[Federal Register Volume 79, Number 180 (Wednesday, September 17, 2014)]
[Proposed Rules]
[Pages 55873-55917]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-21585]
[[Page 55873]]
Vol. 79
Wednesday,
No. 180
September 17, 2014
Part II
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Withdrawal of the
Proposed Rule To Remove the Valley Elderberry Longhorn Beetle From the
Federal List of Endangered and Threatened Wildlife; Proposed Rule
Federal Register / Vol. 79 , No. 180 / Wednesday, September 17, 2014
/ Proposed Rules
[[Page 55874]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R8-ES-2011-0063; FXES11130900000C2-123-FF09E32000]
RIN 1018-AV29
Endangered and Threatened Wildlife and Plants; Withdrawal of the
Proposed Rule To Remove the Valley Elderberry Longhorn Beetle From the
Federal List of Endangered and Threatened Wildlife
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule; withdrawal.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), withdraw the
proposed rule to remove the valley elderberry longhorn beetle
(Desmocerus californicus dimorphus) from the Federal List of Endangered
and Threatened Wildlife under the Endangered Species Act of 1973 (Act),
as amended. This withdrawal is based on our determination that the
proposed rule did not fully analyze the best available information. We
find the best scientific and commercial data available indicate that
the threats to the species and its habitat have not been reduced to the
point where the species no longer meets the statutory definition of an
endangered or threatened species.
DATES: The Service is withdrawing the proposed rule published October
2, 2012 (77 FR 60238) as of September 17, 2014.
ADDRESSES: The withdrawal of our proposed rule, comments and materials
we received, and supplementary documents are available on the Internet
at http://www.regulations.gov at Docket No. FWS-R8-ES-2011-0063. All
comments, materials, and supporting documentation that we considered in
this final agency action are available by appointment, during normal
business hours, at: U.S. Fish and Wildlife Service, Sacramento Fish and
Wildlife Office, 2800 Cottage Way, Suite W-2605, Sacramento, California
95825; telephone 916-414-6600; or facsimile 916-414-6713.
FOR FURTHER INFORMATION CONTACT: Jennifer Norris, Field Supervisor,
Sacramento Fish and Wildlife Office (see ADDRESSES section). Persons
who use a telecommunications device for the deaf (TDD) may call the
Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish this document. Section 4 of the Act and its
implementing regulations (50 CFR part 424) set forth the procedures for
revising the Federal Lists of Endangered and Threatened Wildlife and
Plants. Rulemaking is required to remove a species from the Federal
Lists of Endangered and Threatened Wildlife and Plants, accordingly, we
issued a proposed rule and 12-month petition finding on October 2, 2012
(77 FR 60238) to remove the valley elderberry longhorn beetle as a
threatened species from the List of Endangered and Threatened Wildlife
and to remove the designation of critical habitat for the subspecies.
Based upon our review of public comments, comments from various
Federal, county, and local agencies, peer review comments, comments
from other interested parties, and new information that became
available since the publication of the proposal, we reevaluated
information in our files and our proposed rule. This document withdraws
the proposed rule because the best scientific and commercial data
available, including our reevaluation of information related to the
species' range, population distribution, and population structure,
indicate that threats to the species and its habitat have not been
reduced such that removal of this species from the Federal List of
Endangered and Threatened Wildlife is appropriate.
The basis for our action. A species may warrant protection under
the Act if it is found to be endangered or threatened throughout all or
a significant portion of its range. A species may be determined to be
an endangered species or threatened species because of one or more of
the five factors described in section 4(a)(1) of the Act: (A) The
present or threatened destruction, modification, or curtailment of its
habitat or range; (B) overutilization for commercial, recreational,
scientific, or educational purposes; (C) disease or predation; (D) the
inadequacy of existing regulatory mechanisms; or (E) other natural or
manmade factors affecting its continued existence. Based on our
evaluation of the best scientific and commercial data available
pertinent to threats currently facing the species and threats that
could potentially affect it in the foreseeable future, we determine
that threats have not been reduced such that the species no longer
meets the statutory definition of an endangered or threatened species.
Peer review and public comment. We sought peer review comments from
independent specialists to ensure that our proposed delisting
designation was based on scientifically sound data, assumptions, and
analyses. We invited these peer reviewers to comment on our proposal to
remove the valley elderberry longhorn beetle from the Federal List of
Endangered and Threatened Wildlife. We also considered all other
comments and information received during the public comment periods.
Acronyms and Abbreviations Used in This Document
We use many acronyms and abbreviations throughout this proposed
rule. To assist the reader, we provide a list of these here for easy
reference:
Act = Endangered Species Act of 1973
AFB = Air Force Base
BDCP = Bay Delta Conservation Plan
Cal-IPC = California Invasive Plant Council
CCP = Comprehensive Conservation Plan
CDFG = California Department of Fish and Game (see below)
CDFW = California Department of Fish and Wildlife (formerly CDFG)
CDPR = California Department of Pesticide Regulation
CDWR = California Department of Water Resources
CEQA = California Environmental Quality Act
CFG = California Fish and Game
CFR = Code of Federal Regulations
CNDDB = California Natural Diversity Database
Corps = Army Corps of Engineers
CNLM = Center for Natural Lands Management
CVFPP = Central Valley Flood Protection Plan
CVRMP = Central Valley Riparian Mapping Project
CWA = Clean Water Act
CWP = California Water Plan
DOD = Department of Defense
EO = Element Occurrence
ETL = (Army Corps of Engineers) Engineering Technical Letter
EPA = Environmental Protection Agency
EWPP = Emergency Watershed Protection Program
FR = Federal Register
GCM = global climate model
GHG = greenhouse gas
GIC = Geographic Information Center
GIS = Geographic Information System
HCMP = Habitat Conservation Management Plan
HCP = Habitat Conservation Plan
HRMMP = Habitat Restoration, Monitoring, and Management Program
INRMP = Integrated Natural Resources Management Plan
IPCC = Intergovernmental Panel on Climate Change
LSA = Lake and Streambed Alteration
NAIP = National Agriculture Imagery Program
NEPA = National Environmental Policy Act
NCCP = Natural Community Conservation Planning
NRCS = Natural Resources Conservation Service
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NWR = National Wildlife Refuge
PG&E = Pacific Gas and Electric Company
PGL = (Army Corps of Engineers) Policy Guidance Letter
PVA = Population Viability Analysis
SAMP = Special Area Management Plan
Service = U.S. Fish and Wildlife Service
SPFC = The (California) State Plan of Flood Control
USBR = U.S. Bureau of Reclamation
USDA = U.S. Department of Agriculture
USGS = U.S. Geological Survey
WRCC = Western Regional Climate Center
WRP = Wetland Reserve Program
WRRDA = Water Resources Reform and Development Act
Summary of Changes From the Proposed Rule
Based upon our review of public comments, comments from various
Federal, county, and local agencies, peer review comments, comments
from other interested parties, and new information that became
available since the publication of the proposal (77 FR 60238; October
2, 2012), we reevaluated information in our files and our proposed
rule, making changes as appropriate in this document. Where
appropriate, we incorporated new information that became available
since publishing the proposed rule, information received during the
public comment periods, and in some cases provided additional
discussion of information in our files that may not have been presented
in adequate detail in the proposed rule. This document also provides
important clarifications on the species' biology and threats to the
species. Thus, this determination differs from the proposed rule as
outlined below.
(1) Based on the results of the information received from peer
reviewers and the public, we concluded that some species distribution
information in the proposed rule was incorrectly presented. As a
result, we reevaluated the quality of distribution information
(occurrences) for the valley elderberry longhorn beetle that was
included in our previous summaries (e.g., Valley Elderberry Longhorn
Beetle Recovery Plan (Recovery Plan) (Service 1984, entire); proposed
and final listing rules (43 FR 35636; August 10, 1978; 45 FR 52803;
August 8, 1980); 5-year review (Service 2006a); and proposed delisting
rule (77 FR 60238; October 2, 2012)). This required a reanalysis of the
original data sets in our files throughout the range of the species.
(2) As a result of (1) above and our review of additional sources
of information received during the open public comment periods, we
reexamined existing information in our files. In this document, we
provide either clarifications where necessary, additional or revised
discussions where appropriate (e.g., Population Distribution and
Current Distribution sections under Background), or incorporate and
discuss new information received (e.g., Climate Change and Pesticide
discussion under Factor E, preliminary survey results using aggregation
pheromones under Population Structure in Background).
(3) As a result of (1) and (2) above, as well as information
received after the proposed rule published, we reevaluated and revised
our description of the valley elderberry longhorn beetle's life
history, and its population distribution, range, and occupancy. Our
revised discussions are provided throughout the Background section.
(4) We revised the Summary of Factors Affecting the Species
section, incorporating new or revised information, where appropriate,
in our assessments for these factors. The substantial changes to the
Background section required us to complete a detailed examination of
the five-factor analysis information presented in the proposed rule for
each threat to determine whether the discussions were still valid or
required revisions. Thus, our threats analysis and associated summaries
may differ, where appropriate, from that presented in the proposed
rule.
The primary changes to this document as compared to the proposed
rule are the result of our reanalysis of occurrence and distribution
information of the valley elderberry longhorn beetle. Specifically, we
restructured the five-factor analysis from our proposed rule to reflect
our reanalysis of threats, including additional and more detailed
information (e.g., invasive plants in Factor A and pesticides under
Factor E). We provide a more extensive discussion of effects related to
climate change in Factor A, and incorporate predictions from several
regional climate models for the Central Valley region. We also
incorporate detailed results of several studies (e.g., metapopulation
analysis) and use this information to evaluate the current threats to
the species. Finally, threats related to the effects of pruning
(briefly mentioned in our proposed rule under a Factor E threat (Human
Use) (77 FR 60263; October 2, 2012)) are discussed in this withdrawal
under Factor A.
(5) Based on our reanalysis and the changes described above under
(1) through (4), and primarily as a result of the revised occurrence
and distribution information that affects our evaluation of the factors
impacting the species, we determined that the current and future
threats are of sufficient imminence, intensity, or magnitude to
indicate that the valley elderberry longhorn beetle is likely to become
endangered within the foreseeable future throughout all of its range.
Therefore, the valley elderberry longhorn beetle currently meets the
definition of a threatened species, and we are withdrawing the proposed
rule to delist the valley elderberry longhorn beetle.
Background
Previous Federal Actions
Please refer to the Previous Federal Actions section of the valley
elderberry longhorn beetle proposed delisting rule (77 FR 60238,
October 2, 2012) for a detailed description of the previous Federal
actions concerning this species. On October 2, 2012, we proposed to
remove the designation of the valley elderberry longhorn beetle as a
threatened species under the Act (77 FR 60238). We opened a 60-day
public comment period on the proposed rule that closed on December 3,
2012. On January 23, 2013 (78 FR 4812), we announced a 30-day reopening
of the public comment period for our October 2, 2012, proposed
delisting rule for the species.
Taxonomy and Species Description
The valley elderberry longhorn beetle, Desmocerus californicus
dimorphus, is a member of the family Cerambycidae, subfamily
Lepturinae, and genus Desmocerus (Chemsak 2005, pp. 6-7); adults are
approximately 0.5 to 0.8 inches (in) (13 to 21 millimeters (mm)) long
(Chemsak 2005, p. 6). In North America, the genus Desmocerus includes
three species (D. palliatus, D. californicus, D. aureipennis) and six
subspecies (D. c. californicus, D. c. dimorphus, D. a. aureipennis, D.
a. cribripennis, D. a. piperi, D. a. lacustris) in the United States
and Canada (Chemsak 2005, pp. 4-12). Members of the genus Desmocerus
are brightly colored and sexually dichromatic with antennal tubules
that are not prominently produced at the apex (Chemsak 2005, pp. 2-3).
The protonum (upper surface of the prothorax segment; the midsection
(Evans and Hogue 2006, p. 293)) of the two Desmocerus californicus
subspecies differ from the other two North American species (D.
palliatus, D. aureipennis) with a disk that is densely, confluently
punctate (with small depressions on the disk that flow or run
together), but without large, irregular, and transverse rugae (ridges)
that are about twice as long as broad (Chemsak 2005, p. 3).
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Along the foothills of the eastern edge of the California coast
range and in the southern San Joaquin Valley, the valley elderberry
longhorn beetle range may overlap or abut portions of its range with
the similar-looking California elderberry longhorn beetle (Desmocerus
californicus californicus) (Talley et al. 2006a, p. 5). Prior to 1972,
the valley elderberry longhorn beetle was considered a separate and
valid species (Halstead and Oldham 2000, p. 74). The two elderberry
longhorn beetles are now considered two subspecies (Linsley and Chemsak
1972, pp. 7-8; Chemsak 2005, pp. 5-6). Valley elderberry longhorn
beetle experts indicate that the small number of available specimens
limits the ability to distinguish between the two types based on
characteristics such as body length, elytra length and width, and
antennal hair color (Talley et al. 2006a, p. 5). Thus, the two
subspecies can be identified with certainty only by the adult male
coloration, such that valley elderberry longhorn beetle males have
predominantly red elytra (wing cases) with four dark spots, while
California elderberry longhorn beetle males have dark metallic green to
black elytra with a red border; females of the two subspecies are
similar in appearance (Talley et al. 2006a, p. 4). Atypically colored
(mostly dark) male elderberry longhorn beetles have been observed in
both the center and eastern edge of the valley elderberry longhorn
beetle's range (Talley et al. 2006a, p. 5). Talley et al. (2006a, p. 7)
recommend a systematic geographic morphological and genetic study to
determine the degree of overlap and interbreeding between the two
subspecies.
The obligate larval host plants for both elderberry longhorn
beetles have been described as blue elderberry (Sambucus mexicana) and,
to a lesser extent for the valley elderberry longhorn beetle, red
elderberry (Sambucus racemosa) (Collinge et al. 2001, p. 104; Holyoak
2010, p. 1). However, the current treatment of Sambucus in California
(Family Adoxaceae) describes three taxa: Blue elderberry (S. nigra
subsp. caerulea), black elderberry (S. racemosa var. melanocarpa), and
red elderberry (S. racemosa var. racemosa) (Bell 2012, p. 160). As
noted previously by others (e.g., Talley et al. 2006a, p. 15), the
taxonomic status of Sambucus is imprecise, and blue elderberry is
currently described as ``variable'' and in need of further study (Bell
2012, p. 160). In this rule, we use the more general term, elderberry,
to describe the host plant for the valley elderberry longhorn beetle
since many of the elderberry surveys and their reported results do not
distinguish, or do not identify, the two taxa known to be occupied by
the valley elderberry longhorn beetle (i.e., blue elderberry and red
elderberry). Local climate differences between the more coastal region
occupied by the California elderberry longhorn beetle and the
California Central Valley occupied by the valley elderberry longhorn
beetle may promote different phenologies (e.g., flowering time) of the
host plant and, therefore, differences in time of emergence for the two
subspecies (Talley et al. 2006a, p. 6).
Life History
Similar to other beetles, the valley elderberry longhorn beetle
goes through several developmental stages. These include an egg, four
larval stages (known as ``instars,'' with each instar separated by
molting), pupa, and adult (Greenberg 2009, p. 2).
As reported by Arnold (1984, p. 4), females lay eggs singly on
elderberry leaves and at the junction of leaf stalks and main stems,
with all eggs laid on new growth at the outer tips of elderberry
branches. Based on observations of Desmocerus californicus females
along the Kings River, Halstead and Oldham (1990, p. 24) stated that
females laid eggs at locations on the elderberry branch where the
probing ovipositor (i.e., the female's egg-laying organ) could be
inserted. In a laboratory setting, Barr (1991, p. 46) found that the
majority of eggs laid by a female valley elderberry longhorn beetle
were attached to leaves and stems of foliage (provided as food), with a
preference for leaf petiole-stem junctions, leaf veins, and other areas
containing crevices and depressions. Eggs are approximately 0.09 to
0.12 in (2.3 to 3.0 mm) long and reddish-brown in color with
longitudinal ridges (Barr 1991, p. 4). Eggs are initially white to
bright yellow (Talley et al. 2006a, p. 8) and then darken to brownish
white and reddish brown (Burke 1921, p. 451). Results of captive
studies of Desmocerus californicus indicate the number of eggs produced
per female vary, ranging from 8 to 110 (Burke 1921, p. 25; Arnold 1984,
p. 4; Barr 1991, p. 51). Talley (2003, pp. 153-157) recorded a total of
136 larvae (and an additional 44 eggs that did not hatch) from one
captive female valley elderberry longhorn beetle collected in 2002.
Hatching success has been estimated at 50 to 67 percent of eggs laid,
but survival rates of larvae are unknown (Talley et al. 2006a, p. 7).
In a laboratory setting eggs hatched within a few days of
oviposition (Talley 2003, p. 145), but in the natural setting, the time
to eclosing (development from egg to first instar larvae) is unknown
(Barr 1991, pp. 4-5). Based on laboratory observations, the first
instar larvae may bore immediately into the green tissue of the
elderberry stem at or near the egg site, or larvae may persist on the
shrub surface for several hours (Halstead and Oldham 1990, p. 26).
Previous studies of both subspecies of Desmocerus californicus (Burke
1921, p. 450; Linsley and Chemsak 1972, p. 4) estimated that the larval
development rate inside the plant is 2 years, but laboratory
observations have indicated that a 1-year cycle is possible (Halstead
and Oldham 1990, p. 26). The boring of the larva creates a feeding
gallery (set of tunnels) in the pith at the stem center (Burke 1921, p.
450; Barr 1991, pp. 4-5). While only one larva is found in each feeding
gallery, multiple larvae can occur in one stem if the stem is large
enough to accommodate multiple galleries (Talley et al. 2006a, p. 8).
Prior to pupation, the final (fifth) instar larva chews a larger pupal
cavity in the pith of the stem and creates an exit burrow through the
hardwood just below the surface of the bark of the plant, creating an
exit hole (Halstead and Oldham 1990, p. 23), but then returns inside
the plant stem, plugging the hole with wood shavings (also known as
frass) (Talley et al. 2006a, p. 8). These larvae move back down the
feeding gallery to the enlarged pupal chamber packed with frass, where
they metamorphose into pupae between January and April (Burke 1921, p.
452). Approximately 1 month later, they metamorphose into an adult,
although the adult form may remain in the cavity for several weeks
(Burke 1921, p. 452). The adults chew through the outer bark and emerge
in the spring or early summer through the exit hole, generally
coinciding with the flowering season of the elderberry (Burke 1921, p.
450; Halstead and Oldham 1990, p. 23).
Several studies or surveys have documented the presence of
potential predators (e.g., earwigs, native and nonnative ants) of
valley elderberry longhorn beetle larvae on elderberry shrubs or within
stems (Barr 1991, p. 44; Huxel 2000, pp. 83-84; Holyoak and Graves
2010, pp. 16-17). The Argentine ant (Linepithema humile) is an
invasive, nonnative species that has successfully colonized many areas
of California (Vega and Rust 2001, p. 5), including permanent stream
systems in parts of the Central Valley (Ward 1987, pp. 7-8; Huxel 2000,
p. 84; Klasson et al. 2005, pp. 7-8). Nectar and honeydew are important
food sources for Argentine ants, but studies of feeding behavior have
found that Argentine ants are opportunistic feeders that readily forage
on protein sources such as insect larvae
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or pupae, when available (Rust et al. 2000, p. 209). For example, Way
et al. (1992, pp. 428-431) found that Argentine ants easily located and
removed exposed eggs laid by another arboreal insect borer (Phoracantha
semipunctata (Coleoptera: Cerambycidae)) in studies conducted in
eucalyptus stands in Portugal. See Summary of Factors Affecting the
Species section below for additional discussion of predation threats to
the valley elderberry longhorn beetle.
Collection records indicate that adult valley elderberry longhorn
beetles can be observed from mid-March until early-June, though most
records are from late-April to mid-May (Service 1984, p. 7). However,
the adult stage is rare, both in space and time (Talley et al. 2006b,
p. 649); adults likely die within 3 months (Halstead and Oldham 1990,
p. 22). In a laboratory setting, Arnold (1984, p. 4) recorded females
living up to 3 weeks, but males lived no more than 4 or 5 days.
Similarly, Barr (1991, p. 46) described a life span of 17 days for a
captive male and 25 days for two captive females. Halstead and Oldham
(1990, p. 25) recorded caged adults living from 4 to 66 days in their
experimental studies.
The exit holes created in elderberry stems by the emerging adult
eventually heal, but distinct scars remain on the plant stem (Talley et
al. 2006a, p. 9). Although the presence of exit holes is used to survey
and estimate population size for the valley elderberry longhorn beetle
(Talley et al. 2006a, p. 10) (see additional discussion in Population
Distribution section), this survey technique can be problematic as an
estimate of occupancy for several reasons. First, the exit holes of
both the valley elderberry longhorn beetle and the California
elderberry longhorn beetle are reported to be identical and both
beetles use the same elderberry taxa as their host plants (Arnold
2014b, pers. comm.), making it difficult to determine occupancy of the
two subspecies in areas where their ranges may overlap. Second, surveys
may have included observations of exit holes in dead stems, rather than
only those found in live elderberry stems even though the species uses
only live host plants. Third, once an elderberry stem is abandoned by
the valley elderberry longhorn beetle, other species can occupy the
holes and fill them with frass, making it difficult to confirm that the
feeding chamber was created by the valley elderberry longhorn beetle
(Talley et al. 2006a, p. 10). Finally, birds may also enlarge or rework
valley elderberry longhorn beetle exit holes making them difficult to
identify as such (Jones and Stokes Associates 1987, p. 38).
Adult Behavior and Ecology
Because of the species' rarity, its short-lived adult form, and
difficulty in observing adults in the field, few studies document the
behavior of adult valley elderberry longhorn beetles. Where observed,
adults have been described as feeding on the nectar, flowers, and
leaves of the elderberry plant (Arnold 1984, p. 4; Collinge et al.
2001, p. 105), or flying between trees (Service 1984, p. 7). Mating
likely begins fairly quickly upon emergence. In field studies conducted
in the north Sacramento area, Arnold (1984, p. 4) noted that male adult
valley elderberry longhorn beetles appear more active than female
adults, and males were observed taking short flights both within
elderberry shrubs or to another shrub.
Dispersal distances for the valley elderberry longhorn beetle are
unknown. Based on site occupancy and patterns of colonization and
extinction from 1991 to 1997, Collinge et al. (2001, p. 111) concluded
that the valley elderberry longhorn beetle has limited dispersal
ability. In this and following sections (i.e., Adult Behavior and
Ecology, Population Structure, and Summary under Background), the term
``extinction'' refers to the observations defined and described in the
original citations (e.g., Collinge et al. 2001, entire, and Zisook
2007, entire), and does not refer to extinction of the valley
elderberry longhorn beetle. Talley et al. (2007, p. 28) concluded the
abundance of exit holes was spatially clustered over distances of 33 to
164 feet (ft) (10 to 50 meters (m)) in alluvial plain, riparian
corridors, and upper riparian terrace habitats along portions of the
American River Basin. In this same study, the average distance between
the nearest neighboring (recent) exit hole was estimated at 141 ft (43
m); however, there was a wide range in the distances measured (plus or
minus 144 ft (44 m)) (Talley et al. 2007, p. 28), making it difficult
to draw definitive conclusions for this spatial relationship. Based on
these data, Talley et al. (2007, p. 28) estimated the dispersal
distance of an adult valley elderberry longhorn beetle from its
emergent site to be 164 ft (50 m) or less (Talley et al. 2007, p. 28).
However, Arnold (2014a, pers. comm.) has observed males flying at least
1 mile (mi) (1.6 kilometers (km)) in areas of good habitat. Given the
varying results of these studies (i.e., Collinge et al. 2001; Talley et
al. 2007; Arnold 2014a, pers. comm.) and lack of comprehensive studies
of adult behaviors (e.g., mark and recapture studies), we are not able
to accurately define a precise dispersal distance or assess how
dispersal or other behaviors affect population persistence for this
species. However, we believe that the dispersal ability for this
species range is fairly limited.
Habitat
The valley elderberry longhorn beetle occupies portions of the
Central Valley of California (also known as the Great Valley of
California). The Central Valley is bounded by the Cascade Range to the
north, the Sierra Nevada to the east, the Tehachapi Mountains to the
south, and the coastal ranges and San Francisco Bay to the west. The
valley is a large agricultural region drained by the Sacramento and San
Joaquin Rivers and represents one of the more notable structural
depressions in the world with much of the valley close to sea level in
elevation with very low land surface relief, though elevations are
higher along the valley margins (U.S. Geological Survey (USGS) 2013a).
The climate in the Sacramento Valley and the San Joaquin Basin, which
comprise the northern two-thirds of the Central Valley, can be
characterized by cool, rainy winters and hot, dry summers (USGS 2013a).
The average annual rainfall for the Central Valley ranges from 5 inches
(12.7 centimeters (cm)) at the southern end to over 30 inches (76.2 cm)
at the northern end (U.S. Bureau of Reclamation (USBR) 2014). With more
than three-quarters of this rain coming during a 5-month period
(December through April), seasonal floods are common in the valley due
to heavy winter and spring runoffs. This precipitation pattern often
creates water shortages in the summer and fall when rain is most needed
for irrigation purposes; in low rainfall years, drought conditions are
often observed in the valley (USBR 2014).
In addition to rain falling within the valley itself, snowpack in
the Sierra Nevada Mountains to the east historically provided flows
from numerous rivers and streams into both the Sacramento Valley and
the San Joaquin Valley through late spring (Katibah 1984, p. 24). These
river systems have been altered by artificial levees, river
channelization, dam construction, and water diversions (Katibah 1984,
p. 28).
The primary host plant of the valley elderberry longhorn beetle,
blue elderberry, is an important component of riparian ecosystems in
California (Vaghti et al. 2009, p. 28). As part of the remnant riparian
forests in the Central Valley, elderberry provides wintering, foraging,
and nesting habitat for birds (Gaines 1974, entire; Gaines 1980,
[[Page 55878]]
entire) and supporting habitat for other boring insects and spiders
(Barr 1991, p. 44). Its berries, leaves, and flowers provide food for
wildlife, particularly during dry summer months (Vaghti et al. 2009,
pp. 28-29). Elderberry seeds are likely dispersed by vertebrates,
particularly birds (Talley 2005, p. 57). Elderberry seedlings have
shallow roots, and high rates of mortality have been observed in the
field (Talley 2005, p. 57). Lower seedling mortality rates (about 25
percent in the first year of planting) have been reported from areas
where elderberry plants have been transplanted or where new elderberry
seedlings have been planted (i.e., mitigation sites) where site
conditions are managed (Holyoak et al. 2010, p. 48).
A 1991 survey for the valley elderberry longhorn beetle between the
Central Valley and adjacent foothills recorded elderberry plants (i.e.,
both red and blue elderberry) in habitats ranging from lowland riparian
forest to foothill oak woodland, with elevation ranges from 60 to 2,260
ft (18.3 to 689 m) (Barr 1991, p. 37). Historically, the riparian
forests in the Central Valley consisted of several canopy layers with a
dense undergrowth and included Fremont cottonwood (Populus fremontii),
California sycamore (Platanus racemosa), willows (Salix sp.), valley
oak (Quercus lobata), box elder (Acer negundo var. californicum),
Oregon ash (Fraxinus latifolia), and several species of vines (e.g.,
California grape (Vitis californica) and poison oak (Toxicodendron
diversilobum)) (Service 1984, p. 6). These plant communities encompass
several remaining natural and semi-natural floristic vegetation
alliances and associations within the Great Valley Ecoregion of
California (see Buck-Diaz et al. 2012, pp. 12-23). The 1991 survey
conducted by Barr noted that elderberry was found most frequently in
mixed plant communities, and in several types of habitat, including
non-riparian locations, as both an understory and overstory plant (Barr
1991, pp. 40-41) with adults and exit holes created by the valley
elderberry longhorn beetle found most commonly in riparian woodlands
and savannas (Barr 1991, p. 41). Based on surveys completed along the
Sacramento River, Gilbart (2009, p. 51) concluded that the valley
elderberry longhorn beetle shows a preference for moderate amounts of
cover, but that its occupancy is reduced with some canopy-producing
plants, such as box elders, cottonwoods, and willows.
Nonnative plants observed in vegetation communities containing
elderberry include giant reed (Arundo donax), brome (Bromus spp.), and
bur chervil (Anthriscus caucalis) (Vaghti et al. 2009, pp. 33-35).
Black locust (Robinia pseudoacacia) and black walnut (Juglans hindsii)
have been identified as important invasive species that can displace
native plants in riparian floodplains in the Central Valley (Hunter
2000, p. 275; Vaghti et al. 2009, pp. 33-35) (see Summary of Factors
Affecting the Species section below).
Talley et al. (2006a, p. 10) stated that the valley elderberry
longhorn beetle is found most frequently and most abundantly in areas
that support significant riparian zones (see also Talley et al. 2007,
discussed below). In a study to evaluate the occupancy of the valley
elderberry longhorn beetle (based on exit hole observations) in
roadside habitats in the northern Central Valley (2006-2008), Talley
and Holyoak (2009, p. 8) found that site occupancy rates and rates of
elderberry shrub occupancy within occupied sites were higher in
riparian vegetation compared with non-riparian vegetation. Hydrological
processes, specifically inundation duration and frequency, when
measured by relative elevation above a river or creek floodplain, were
found to significantly influence the distribution of elderberry in the
lower alluvial reaches of the American River, Cache Creek, Cosumnes
River, and Putah Creek (Talley 2005, pp. 52, 55, 66). The highest
frequency of elderberry shrubs was found within an intermediate
relative elevation gradient, that is, between areas influenced by
flooding processes (low elevations) and water availability (higher
elevations) (Talley 2005, pp. 45, 66). Talley (2005, pp. 56-58) also
noted that the differences in relationships between elderberry
abundance (number of shrubs within each elderberry patch), lateral size
(shrub diameter), and stress level (proportion of dead stems per shrub)
within the four river systems studied were attributed to stochastic
(random) processes related to seed dispersal patterns and seedling
mortality.
Several studies have evaluated specific elderberry plant
characteristics (e.g., size of stems, density of stems, and height
above ground) relative to the valley elderberry longhorn beetle's life-
history requirements and its abundance or presence (Jones and Stokes
Associates 1987, pp. 27-32; Barr 1991, pp. 37-42; Collinge et al. 2001,
pp. 107-109; Talley 2005, pp. 14-15, 17-19; Talley et al. 2007, entire;
Holyoak and Koch-Munz 2008, entire). A detailed analysis of habitat and
habitat quality for the valley elderberry longhorn beetle was completed
based on surveys from 2002 to 2004 within one section of the American
River Basin (American River Parkway) (Talley et al. 2007, entire). The
study identified several predictors of habitat occupancy in the area
surveyed and found that, in general, density of elderberry shrubs and
shrub size, number of stems, and range of branch sizes were the most
influential predictor variables (Talley et al. 2007, p. 30). Valley
elderberry longhorn beetle exit holes were observed most frequently in
elderberry stems or branches with a diameter of 0.8 to 2.76 inch (2 to
7 cm) and at a height of 0 to 3.28 ft (0 to 1 m) above ground, which
may be the result of the size of the main stems of elderberry shrubs
(Talley et al. 2007, p. 30). Of the four types of habitats evaluated
within the study area, riparian cover types contained the greater
quality of habitat, specifically upper riparian terrace and lower
alluvial plain habitats (Talley et al. 2007, p. 30).
There are limited studies on the relationship of the valley
elderberry longhorn beetle's life-history features and those of its
host plants, and the significance of this relationship to the ecology
of riparian or other native plant communities where the species is
found. Based on comprehensive surveys of elderberry taxa surveyed
within the Central Valley in 1991, Barr (1991, p. 50) concluded that
the presence of the valley elderberry longhorn beetle was not a factor
in the health of elderberry host plants, nor were unhealthy host plants
a factor determining the presence of the beetle. Gilbart (2009, entire)
evaluated the relationship between the occupancy of the valley
elderberry longhorn beetle and the health of blue elderberry planted at
restoration sites along the Sacramento River (within the Sacramento
River National Wildlife Refuge (NWR)). Results from this study found a
correlation between occupancy and dead biomass (versus between
occupancy and age), which supports results from other studies regarding
the valley elderberry longhorn beetle's preference for plants with
partial bark damage or that are otherwise stressed (e.g., low to
moderate levels of damaged stems from pruning or burning), or for
shrubs with, on average, 25 to 50 percent dead stems (Arnold 1984, p.
4; Holyoak and Koch-Munz 2008, pp. 447-448).
Gilbart (2009, p. 54) stated that valley elderberry longhorn
beetles likely use olfaction to locate host plants and mates, and
volatiles released from the stressed tissue in elderberry shrubs are
likely to be the initial cue used for host plant and mate location.
This analysis also found that, although the exit holes
[[Page 55879]]
created by the valley elderberry longhorn beetle may increase the dead
biomass of elderberry shrubs, an increase in plant cover has a greater
effect on dead biomass and is independent of the occupancy of the
beetle (Gilbart 2009, pp. 53-54). Additional studies are needed to
determine the relationships between the valley elderberry longhorn
beetle's occupancy and: (1) The regenerative ability and timing of
elderberry stem growth; (2) the beetle's observed preference for
elderberry stems of a certain minimum diameter relative to the host
plants' life history; and (3) other factors related to the ecological
role of elderberry found in the species' range in the Central Valley.
In an unpublished evaluation of environmental factors important to
the valley elderberry longhorn beetle, Zisook (2007, entire) evaluated
colonization and extinction events based on survey data from the Talley
et al. (2007, entire) study along the American River Parkway. Zisook
(2007, p. 5) found that colonization events were more likely to occur
on shrubs located on north-facing slopes and on relatively large and
previously occupied shrubs. Extinction events were more likely to be
associated with relatively small elderberry shrubs, shrubs with stem
damage, and in areas with larger floodplain widths (Zisook 2007, p. 5).
In their evaluation of elderberry characteristics at mitigation sites
compared with natural sites, Holyoak and Koch-Munz (2008, pp. 449-450)
noted that, within mitigation sites, the abundance of the valley
elderberry longhorn beetle per elderberry shrub was positively related
to the size and age of the mitigation site, and the species was more
likely to be present in elderberry shrubs with low levels of damage
(e.g., partial bark damage) at these sites (see also discussion in
Adult Behavior and Ecology section above). Relatedly, Talley et al.
(2007, p. 28) found that the presence of recent exit holes was
correlated with previous occupancy (that is, 73 percent of elderberry
shrubs with recent holes also had old holes). A similar result was
found in a 2010 survey effort, in which all but one watershed sampled
had both new holes and old holes (in both dead and live wood) (Holyoak
and Graves 2010, p. 12). Additional habitat characteristics relative to
spatial relationships of elderberry shrubs and occupancy of the valley
elderberry longhorn beetle are summarized in our metapopulation
structure discussion (see Population Distribution section below).
Population Distribution
There are few recorded observations of adult valley elderberry
longhorn beetles; many of the locations for this species in various
references, including previous Service documents, are based exclusively
on observations of exit holes. The population distribution of the
valley elderberry longhorn beetle described in our proposed delisting
rule (77 FR 60238; October 2, 2012) relied heavily on the records
provided in the California Natural Diversity Database (CNDDB) as
Element Occurrences (EOs). The CNDDB, maintained by the California
Department of Fish and Wildlife (CDFW; formerly known as California
Department of Fish and Game (CDFG)), is an ongoing effort to include
observations and survey reports for separate EOs of all of the species
and subspecies tracked by the database. However, because contribution
to the database is not mandatory, some observations or surveys as well
as negative survey results for plants and animals (including the valley
elderberry longhorn beetle) are not included in the database;
therefore, the CNDDB should not be considered an exhaustive or
comprehensive inventory of all rare species in California (CDFW 2014c).
For animals with limited mobility, which includes most invertebrates,
an EO is defined as a location where a specimen was collected or
observed, and is assumed to represent a sample of a breeding population
(CDFG 2007, p. 1). Sequential surveys are accumulated in EO reports for
each location of a species.
There are important limitations to consider when using the CNDDB
records to examine the population distribution and abundance of the
valley elderberry longhorn beetle. First, despite the date (year) of
the observations, CNDDB considers all occurrences of the valley
elderberry longhorn beetle as presumed extant, even though many of
these records are more than 20 years old. Second, the occurrence rank
(a measure of the condition and viability of a particular occurrence
that takes into account population size, viability, habitat quality,
and disturbance) used by CNDDB (based on NatureServe definitions;
NatureServe 2014) for many of the valley elderberry longhorn beetle EOs
are considered ``poor'' (occurrence has a high risk of extirpation) or
``unknown'' (rank not assigned due to lack of sufficient information on
the occurrence). In addition, many of the records described in the
CNDDB report represent only observations of exit holes. As noted above
in Life History section, these observations may represent: (1) Old exit
holes created by the valley elderberry longhorn beetle; (2) exit holes
created by the California elderberry longhorn beetle within areas where
their ranges overlap; or (3) holes created by other species.
Our review of the 2013 CNDDB EO report for the valley elderberry
longhorn beetle found that 72 percent (142 of 196) of the EOs represent
observations of only exit holes, and 23 percent (46 of 201) of the EOs
are described as adult beetles (male, female, or unknown sex) (CNDDB
2013, entire; Arnold 2014a, pers. comm.). Only 12 percent (24 of 201)
of the EOs identify observations of adult males (CNDDB 2013, entire;
Arnold 2014a, pers. comm.), and four of these records (within Tulare
County) are likely to be observations of the California elderberry
longhorn beetle since no typically colored male specimens have been
observed or collected from this County (Talley et al. 2006a, p. 5).
Presumed Historical Range
Prompted by comments received from peer reviewers, local agencies,
the public, and other interested parties during our two open comment
periods on the proposed delisting rule (77 FR 60238; October 2, 2012:
78 FR 4812; January 23, 2013), and our reassessment of the CNDDB
occurrences (CNDDB 2013, entire), and other references (e.g.,
elderberry mitigation or conservation banks, biological opinions
prepared by the Service, and other unpublished reports), we are
defining in this withdrawal notice the presumed historical range of the
valley elderberry longhorn beetle based on:
(1) A georeferenced version (Service 2014, Geographic Information
System (GIS) analysis) of the distribution map illustrated in Chemsak
(2005, p. 7).
(2) The distribution defined in Talley et al. (2006a, pp. 4-6),
which was based on museum specimens and sightings of adult males.
(3) The distribution map (also georeferenced) of museum and other
specimens depicted in Halstead and Oldham (1990, p. 51 (Figure 22)).
(4) Locations of observations of adult male valley elderberry
longhorn beetles described in the CNDDB report (CNDDDB 2013, entire) or
in other survey results not recorded in CNDDB (River Partners 2010,
entire; Arnold and Woollett 2004, p. 8; Arnold 2014a, pers. comm.).
We did not use the locations presented in Halstead and Oldham
(2000, p. 75) to develop this presumed historical range since their
publication did not distinguish between the two subspecies.
[[Page 55880]]
The presumed historical range of the valley elderberry longhorn
beetle represents a patchy distribution from Tehama County to Fresno
County, as shown in Figure 1 below (Service 2014, GIS analysis).
Observations of adult beetles have been reported from Shasta County in
2008 and 2009 (CNDDB EO 218), as well as exit holes in 1991 and 2007
through 2012 (CNDDB EO 218; Holyoak and Graves 2010, p. 23), and an
unconfirmed adult male valley elderberry longhorn beetle in 2013 (Souza
2014, pers. comm.). We did not include Shasta County within our
presumed historical range because of the difficulty in distinguishing
female valley elderberry longhorn beetle from female California
elderberry longhorn beetle, the unconfirmed observation of an adult
male valley elderberry longhorn beetle, and the absence of museum
specimens from this area. However, we acknowledge that the recent
observations of exit holes in portions of Shasta County (along the
Sacramento River) may represent an expansion of the historic range of
the valley elderberry longhorn beetle to this location. With regard to
recorded CNDDB observations of valley elderberry longhorn beetle in
Tulare County, it is important to note that there is significant
uncertainty as to whether the male and female adult beetles observed in
that area represent observations of the valley elderberry longhorn
beetle or the California elderberry longhorn beetle (CNDDB EOs 63, 66,
128, 154). Based on the distribution map prepared by Chemsak (2005, pp.
6-7) and the discussion (and map) presented in Talley et al. (2006a,
pp. 5-6), it is reasonable to conclude that the Tulare County
observations likely represent the California elderberry longhorn
beetle.
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Current Distribution (Since 1997)
The most recent, comprehensive rangewide survey by observers known
to be qualified to detect occupancy of the valley elderberry longhorn
beetle was conducted in 1997 (see Collinge et al. 2001, entire).
Collinge et al. (2001, entire) resampled 65 of 79 sites surveyed by
Barr in 1991 and 7 additional sites within the Central Valley in 1997.
Within the last 10 years, surveys in the Central Valley for the
valley
[[Page 55882]]
elderberry longhorn beetle have included the following:
(1) Examining 4,536 elderberry shrubs in the Lower American River
(14.9 mi) (24 km) and Putah Creek (28 km (17.4 mi)) (Talley 2005,
entire).
(2) Conducting exit hole surveys in 2010 of both elderberry shrubs
(441) and stems (4,247) in 10 watersheds from Shasta to Tulare Counties
(34 sites) (Holyoak and Graves 2010, entire).
(3) Conducting surveys of potential and occupied valley elderberry
longhorn beetle habitat within riparian areas along the Stanislaus
River (59 mi (95 km)) and San Joaquin River (12 mi (19.3 km)) in 2006
(River Partners 2007, entire).
It should be noted that some of the surveys described above were
conducted within areas located adjacent to public roads or within
accessible areas such as public parks (i.e., ``convenience'' sampling)
in order to more easily access and examine shrubs for exit holes, or to
better observe adults. Therefore, survey results should not be
considered as a complete representation of the entire population
distribution (or occupancy) of the valley elderberry longhorn beetle at
the time of the particular survey.
In this withdrawal, we provide a reevaluation of the valley
elderberry longhorn beetle occurrence records described in our proposed
rule, and we also incorporate new information received since the
proposed delisting rule was published on October 2, 2012 (77 FR 60238).
This reanalysis now provides the most accurate assessment of the
presumed extant occurrences of the valley elderberry longhorn beetle
(based on the best available commercial and scientific information) as
compared to what was presented in the proposed rule. Specifically, we
started with identifying CNDDB EOs (adults or exit holes, any age)
observed since 1997 (past 16 years), as this was the year in which the
most recent, comprehensive rangewide survey by observers known to be
qualified to detect occupancy of the species was conducted (Collinge et
al. 2001). Next, a subset of these CNDDB EO records were used if they
had an Occurrence Rank of ``fair'' (occurrence characteristics are non-
optimal, and occurrence persistence is uncertain in current
conditions), ``good'' (occurrence has favorable characteristics and is
likely to persist for the foreseeable future (20-30 years), if current
conditions prevail) or ``excellent'' (occurrence has optimal or
exceptionally favorable characteristics and is very likely to persist
in foreseeable future (20-30 years), if current conditions prevail)
(NatureServe 2014).
In addition, we incorporated into our reanalysis records from:
(1) Observations of exit holes (recent holes only based on level of
detail available) from surveys conducted in 1997 (Collinge et al. 2001,
entire; Collinge 2014 pers. comm.).
(2) Exit hole (any age) and adult beetle locations in four
watersheds (Lower American River, Putah Creek, Cache Creek, Cosumnes
River) from 2002-2005 surveys (Talley 2014a, pers. comm.).
(3) Exit hole (any age) locations from 10 watersheds as described
in Holyoak and Graves (2010, entire).
(4) Exit hole (any age) locations along the Stanislaus and San
Joaquin Rivers from River Partners (2007, entire).
(5) Adult beetle observations along the Feather and Sacramento
Rivers from River Partners (2010 and 2011; entire).
(6) Exit hole (any age based on detailed information available from
recent data sets) locations recorded at Beale Air Force Base
(Department of Defense (DOD 2014, unpublished GIS data)).
Of the currently described 201 CNNDB records (CNDDB 2013, entire)
for the valley elderberry longhorn beetle, 142 EOs represent
observations of only exit holes, 52 EOs represent observations from
1997 to 2013, and 25 EOs represent observations from 1997 to 2013 with
an Occurrence Rank of ``fair,'' ``good,'' or ``excellent.''
We then selected the locations of observations (exit holes or
adults) found within our defined presumed historical range (as shown in
Figure 1) for the valley elderberry longhorn beetle. These locations
(which represent 17 EOs) are summarized in Table 1 by their
geographical location (e.g., hydrological feature) and illustrated in
Figure 2. Of note, we could not locate (using GIS software (Service
2014, GIS analysis) with an acceptable level of accuracy the six
mitigation site survey locations (2005 and 2006) from Holyoak and Koch-
Munz (2008, Appendix A1); thus, these six locations were not included
in Table 1 or Figure 2. However, many, if not all, of these six
mitigation site locations are within watersheds where occupancy (exit
holes) of the valley elderberry longhorn beetle has been observed
within the last 16 years, or are locations that were reported in the
CNDDB EO report (CNDDB 2013, entire).
Table 1--Geographical Locations of Valley Elderberry Longhorn Beetle
Occurrences Since 1997 in California, Grouped by Hydrologic Unit. Based
on Observations (Adults or Exit Holes), Including CNDDB EOS With an
Occurrence Rank of ``Fair, Good, or Excellent,'' and Other Survey
Results Within the Valley Elderberry Longhorn Beetle's Presumed
Historical Range
[See Figure 1]
[Sources: Collinge et al. 2001; Holyoak and Graves 2010; River Partners
2007, 2010, 2011; CNDDB 2013; Collinge 2014, pers. comm.; Talley 2014a,
pers. comm.; DOD 2014.]
------------------------------------------------------------------------
Type of observation
Hydrologic unit Geographical (adult,\1\ exit Year last
location holes) observed
------------------------------------------------------------------------
Thomes Creek-Sacramento River:
Millrace Creek................ Adult (unknown), 2001
Exit Holes.
Salt Creek.................... Adult (both), Exit 2001
Holes.
Sacramento River (SSE of Red Adult (both), Exit 2001
Bluff). Holes.
Big Chico Creek-Sacramento River:
Sacramento River (E of Exit Holes.......... 2010
Corning).
Sacramento River (Glenn-Colusa Adult (male)........ 2002
Irrigation District
Mitigation Site).
Sacramento River Mitigation Exit Holes.......... 2003
Area (aggregation of shrubs,
many exit holes \2\).
Big Chico Creek (two Exit Holes.......... 1997
locations).
Sacramento-Stone Corral:
Sacramento River (N of Colusa) Exit Holes.......... 2010
Honcut Headwaters-Lower Feather:
Feather River (SW of Oroville) Exit Holes.......... 2010
(three locations).
Feather River (Feather River Adult (both)........ 2010
Elderberry Transplant Area).
[[Page 55883]]
Feather River (5 mi N of Exit Holes.......... 1997
Marysville).
Feather River (Star Bend Adult (both)........ 2010
Elderberry Mitigation Site)
(two locations).
Feather River (10 mi SW of Exit Holes.......... 2010
Wheatland) (two locations).
Reeds Creek (Beale AFB)....... Exit Holes.......... 2012
Upper Bear:
Bear River (SSE of Wheatland). Adult (unknown), 2003
Exit Holes.
Bear River (4 mi SW of Exit Holes.......... 2010
Wheatland) (three locations).
Best Slough/Dry Creek (Beale Exit Holes.......... 2005
AFB).
North Fork American:
Folsom Lake (NW Shore)........ Exit Holes.......... 1997
Folsom Lake................... Exit Holes.......... 2010
Lower American:
Miners Ravine (tributary of Exit Holes.......... 1997
Dry Creek).
American River Parkway Adult (female), Exit 2010
(aggregation of shrubs, many Holes.
exit holes).
Upper Cache:
Cache Creek (many locations).. Exit Holes.......... 2003
Lower Sacramento:
Willow Slough (SW of Esparto). Adult (male), Exit 2001
Holes.
RD-900 Canal (W of Sacramento Adult (both)........ 2006
River).
Sacramento River (SW of Adult (male)........ 2005
Sacramento).
Upper Putah:
Putah Creek (aggregation of Adult (unknown), 2010
shrubs, many exit holes). Exit Holes.
Upper Cosumnes:
Cosumnes River (24 locations). Exit Holes.......... 2003
Upper Mokelumne:
South of Mokelumne River...... Exit Holes.......... 2006
Upper Calaveras:
Calaveras River............... Exit Holes.......... 2000
Upper Stanislaus:
Stanislaus River (N of Exit Holes.......... 2010
Modesto) (two locations,
several areas).
Bear Creek (tributary of Adult (female)...... 2002
Stanislaus River).
South of Mountain Pass Creek Adult (female)...... 2007
(S of Yosemite Jct.;
tributary of Stanislaus
River).
Upper Tuolumne:
Tuolumne River................ Exit Holes.......... 1999
Algerine Creek (tributary of Exit Holes.......... 2007
Tuolumne River).
Upper Merced:
Merced River (S of Modesto)... Exit Holes.......... 2010
Tulare Lake Bed:
Kings River (E of Centerville) Adult (both), Exit 1998
Holes.
------------------------------------------------------------------------
\1\ Some adult valley elderberry longhorn beetle observations were not
identified as either male or female, and some observations were
identified to include both males and females.
\2\ The term ``many'' in this table is defined as a value greater than
50.
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Table 1 represents a reevaluation of the 26 ``locations'' listed in
the proposed rule (77 FR 60242-60243 (Table 1); October 2, 2012) based
on our assessment of observations since 1997, while incorporating our
current description of the presumed historical range of the valley
elderberry longhorn beetle (see Presumed Historical Range section
above). This revision of presumed extant occurrences (as
[[Page 55885]]
compared to Table 1 in the proposed delisting rule) is based on: (1) A
review of the quality of the CNDDB EOs (type of observation, the year
of last observation, and occurrence rank); (2) additional data sets (as
discussed above and represented in Figure 2); (3) comments received
from the peer reviewers, Federal, County, and local agencies, the
public, and other interested parties relative to occupancy; and (4) a
new grouping of geographical locations based on hydrologic units
defined by a national watershed boundary dataset (USGS 2013b). Since
some observations did not distinguish between old and recent exit
holes, we include observations of both old (greater than 1 year old)
and recent (i.e., greater than or equal to 1 year) exit holes for most
survey results.
Taken together, these data (presented in Table 1 and Figure 2)
describe an uncommon or rare, but locally clustered, occupancy of the
valley elderberry longhorn beetle within the presumed historical range
over the past 16 years within approximately 18 hydrologic units (USGS
2013b) and 36 geographical locations within the Central Valley. The 36
geographical locations are considered to be discrete from each other
based on a presumed maximum dispersal distance of approximately 1 mi
(1.6 km) based on observations of male beetles from Arnold (2014a,
pers. comm.), but in some areas (e.g., Putah Creek) they include
several areas of elderberry habitat within that location. As shown in
Table 1, 61 percent (22 of 36) of the geographical locations are areas
where only exit holes have been used to define occupancy, which is the
result of both the survey methods used and the difficulty in observing
adult valley elderberry longhorn beetles. Twenty-five percent (9 of 36)
of the geographical locations within 4 hydrologic units represent
observations of adult males recorded since 1997.
Restoration and Mitigation Sites
A large amount of monetary resources has been invested in
floodplain restoration along sections of the Sacramento River for the
purpose of restoring riparian areas that serve as habitats for native
plants and wildlife, including the valley elderberry longhorn beetle
(Golet et al. 2008, p. 2; Golet et al. 2013, entire). Holyoak et al.
(2010, p. 50) estimated that an average of 2.5 mitigation sites were
initiated per year, with more than 1,000 elderberry and 6,000 native
plants planted per year for the 1989-1999 time period. Our proposed
rule described a number of conservation easements or banks, mitigation
and restoration sites, and other conserved areas that have been
established within the current range of the valley elderberry longhorn
beetle, which we estimated to be approximately 21,536 ac (8,715 ha) (77
FR 60256-60258; October 2, 2012).
Mitigation for the valley elderberry longhorn beetle generally
consists of planting elderberry seedlings and associated native plants
and transplanting mature elderberry shrubs from impacted sites to
mitigation sites (Holyoak et al. 2010, pp. 44, 46). In our proposed
rule, we provided an estimate (642 to 1,900 ac (260 to 769 ha)) of
valley elderberry longhorn beetle habitat protected through measures
associated with section 7 consultations or through conservation or
mitigation measures established through Habitat Conservation Plans
permitted under section 10 of the Act (see Factor D discussion below)
(77 FR 60258; October 2, 2012). We also identified another large
riparian area (4,600 ac (1,862 ha)) along the American River (the
American River Parkway) that contains critical habitat for the valley
elderberry longhorn beetle, but the amount of occupied elderberry
habitat is not known (77 FR 60258; October 2, 2012). However, we
indicated in the proposed rule that an unknown proportion within these
areas (i.e., conservation easements, mitigation sites, restoration
sites, etc.) actually contain elderberry shrubs and only a proportion
of that (unknown) estimate contains habitat occupied by the valley
elderberry longhorn beetle.
By mid-2013, approximately 2,698 elderberry shrubs (covering 1,000
ac (405 ha)) were expected to be planted by Pacific Gas and Electric
Company (PG&E) in conservation areas located near or adjacent to
existing elderberry populations in the Central Valley (Ross-Leech 2012,
pers. comm.). Valley elderberry longhorn beetle exit holes have been
recorded at five locations where PG&E is conducting biannual monitoring
(Ross-Leech 2012, pers. comm.). PG&E has established mitigation sites
in several counties to compensate for project-specific effects to the
valley elderberry longhorn beetle. Fifteen sites are located in Tehama
and Yolo Counties, with approximately 1,228 elderberries successfully
established (as of 2002), and occupancy of the valley elderberry
longhorn beetle (adults or exit holes) has been observed at 11 of the
15 sites (Ross-Leech 2012, pers. comm.).
The Center for Natural Lands Management (CNLM) manages four
preserves in the Central Valley where naturally occurring or planted
elderberry are found; CNLM owns three and holds a conservation easement
on the other (Rogers 2012, pers. comm.). Management practices being
implemented at these sites appear to be consistent with maintaining
elderberry habitat; however, the protection and stabilization of the
valley elderberry longhorn beetle is not the primary management
objective for the preserves, and funding is limited for management
activities to specifically support valley elderberry longhorn beetle
conservation (Rogers 2012, pers. comm.) Two of these preserves (Pace
and Keeney in San Joaquin and Butte Counties, respectively) have
recorded valley elderberry longhorn beetle exit holes within the past 3
to 10 years; however, no monitoring for the species has been conducted
within the other two preserves (Oxbow in San Joaquin County and Dublin
Ranch in Alameda County) or within the Mehrton conservation bank
(Sacramento County) that CNLM neither owns nor manages (Rogers 2012,
pers. comm.). We describe restoration efforts of elderberry habitat
located within National Wildlife Refuges in the Central Valley below,
under Factor D, Other Conservation Programs.
Transplanted elderberry shrubs appear to be important in the
colonization of mitigation sites by the valley elderberry longhorn
beetle. For those sites where there was no potential introduction of
the species via transplanted shrubs, one study found a 13.4 percent
colonization rate for transplanted areas as compared to 2.3 percent for
seedlings (Holyoak et al. 2010, p. 49). As noted in this study, it can
take approximately 7 years for elderberry shrubs to grow large enough
to support the life-history requirements of the valley elderberry
longhorn beetle, but monitoring is generally required only for 10-15
years (Holyoak et al. 2010, p. 51). Thus, the observed low colonization
rates are not unexpected, and the authors suggest that prescribed
monitoring periods may not be of long enough duration for the species
to find and use its host plant (Holyoak et al. 2010, p. 51). The study
found that the occupancy for the valley elderberry longhorn beetle was
43 percent for all sites through either introduction associated with
transplanted elderberry shrubs or through colonization (Holyoak et al.
2010, pp. 49-50). Overall, the conclusions from this study suggest that
transplantation of elderberry is important for the species because the
transplanted shrubs can contain the larval stage of the valley
elderberry longhorn beetle or the shrubs are large
[[Page 55886]]
enough for the species to be able to recolonize areas within its range.
Small mitigation sites may not be of sufficient size to support
recolonization of the valley elderberry longhorn beetle. The mitigation
study conducted by Holyoak and Koch-Munz (2008, entire) highlighted the
size differential between mitigation sites established for the valley
elderberry longhorn beetle (mean 1.83 ac (1.74 ha) versus natural areas
(mean 7.5 ac (3 ha)), and the authors concluded that the smaller sites
established for mitigation are contributing to the habitat
fragmentation for this species (Holyoak and Koch-Munz 2008, p. 452).
The mitigation review by Holyoak et al. (2010, p. 51) also emphasized
the importance of using transplants in reproducing populations of the
valley elderberry longhorn beetle, and they recommended shrubs be
transplanted to older mitigation sites that already contain elderberry
plants of sufficient size such that the valley elderberry longhorn
beetle species does not have to rely solely on transplanted shrubs for
its survival. Holyoak et al. (2010, p. 49) reported that the valley
elderberry longhorn beetle most frequently entered mitigation sites
within elderberry shrubs that were transplanted from the site that was
impacted. Their study found that the valley elderberry longhorn beetle
was found at 28 percent of all mitigation sites, but at 88 percent of
mitigation sites to which elderberry shrubs potentially containing
valley elderberry longhorn beetles were transplanted; thus, only 16
percent of sites were colonized by the valley elderberry longhorn
beetle on their own (Holyoak et al. 2010, p. 51). In addition, Holyoak
et al. (2010, p. 51) suggested using transplanted elderberry shrubs
within (not between) watersheds to avoid disruption of potential
genetic population structures. However, we are unaware of studies that
have investigated valley elderberry longhorn beetle genetics between
populations.
Perhaps more importantly, in addition to incorporating appropriate
measures of size and appropriate elderberry characteristics in
achieving successful occupancy of the valley elderberry longhorn beetle
at restoration and mitigation sites, restoring natural riverine
processes is also necessary to achieve functional restoration of
remnant riparian ecosystems (e.g., Golet et al. 2013, entire).
Restoring riverine processes typically requires maintaining a
hydrologic connection of floodplain areas with river systems and
managing a flow regime for both ecological and human needs (Golet et
al. 2008, p. 20). The continued planting of seedlings or
transplantation of shrubs at unsuitable mitigation or restoration sites
is not only costly in resources, but represents a strategy that will
likely not successfully achieve an elderberry shrub age class that
provides a viable conservation value for the valley elderberry longhorn
beetle and other wildlife.
Population Structure
The concepts of metapopulations, metapopulation theory, and the
modeling of metapopulations have become increasingly useful tools for
applying principles of landscape ecology to biological conservation.
Metapopulations are defined as a system of discrete subpopulations that
may exchange individuals through dispersal, migration, or human-
mediated movement (Breininger et al. 2002, p. 405; Nagelkerke et al.
2002, p. 330). Metapopulation models can provide a way to analyze and
predict the response of individual species to habitat fragmentation and
other landscape elements (Beissinger et al. 2006, p. 15).
The effects of spatial diversity (heterogeneity) on the
distribution of the valley elderberry longhorn beetle were assessed
using survey data collected at Central Valley study sites over 2 years
(2002-2004) by Talley (2007, entire) that integrated patch (fine
scale), gradient (broad scale), and hierarchical (mosaic of discrete
multi-scale patches) spatial frameworks. The analysis revealed that a
hierarchical spatial framework explained the most variance in the
occupancy of the valley elderberry longhorn beetle (for the three river
systems in which a spatial framework for the species was identified)
(Talley 2007, p. 1484). However, an integrative approach of all three
spatial frameworks (patch, gradient, and hierarchical) best defined a
population structure for the valley elderberry longhorn beetle (Talley
2007, p. 1486). This population structure can be characterized as
patchy-dynamic, with regional distributions made up of local
aggregations of populations (Talley 2007, p. 1486). These localized
populations are defined by both broad-scale or continuous factors
associated with elderberry shrubs (e.g., shrub age or densities) and
environmental variables associated with riparian ecosystems (e.g.,
elevation, associated trees) that themselves have patch, gradient, and
hierarchical structures (Talley 2007, p. 1486).
Based on surveys conducted from 2002-2004, Talley (2005, pp. 25-26)
concluded that the valley elderberry longhorn beetle vulnerable
developmental stages (i.e., exposure of eggs and larvae) and its rarity
(i.e., low local numbers, low occupancy) are important elements of the
observed metapopulation structure of the species. Talley (2005, pp. 25-
26) further concluded that large-scale catastrophic events and local
changes in random processes or events (i.e., environmental
stochasticity) have the potential to negatively affect riparian systems
and, therefore, the species' vulnerability. Results from several other
surveys of exit holes support the rarity traits such as low local
numbers and low site-occupancy exhibited by the valley elderberry
longhorn beetle:
(1) Estimates of occupancy, as measured by recent (new) exit hole
observations per elderberry groups (or site), in the Central Valley
were reported by Collinge et al. (2001, p. 105), based on surveys
conducted in 1991 and 1997 (see Barr 1991, entire; Collinge et al.
2001, entire). From these two surveys, Collinge et al. (2001, p. 105)
estimated an occupancy rate of approximately 20 percent for both 1991
and 1997.
(2) A 2003 survey of planted elderberry shrubs (planted from 1993
to 2001) within restoration sites on the Sacramento River NWR found 0.6
to 7.9 percent shrubs contained exit holes (average per refuge unit)
(River Partners 2004, pp. 2-3).
(3) A 2007-2008 survey of restoration sites within eight units of
the Sacramento River NWR reported 21 percent occupancy based on
observations of new exit holes (Gilbart 2009, p. 40).
(4) A 2010 survey of valley elderberry longhorn beetle exit holes
within both elderberry shrubs and stems at 34 sites in 10 watersheds
(American River to Tule River) determined the following occupancy
(abundance) estimate information (Holyoak and Graves, 2010, entire;
Holyoak and Graves 2010, Appendix 1):
Forty-seven percent, or 16 of 34 sites, had new exit holes
in elderberry shrubs.
Ninety percent of the watersheds surveyed had new exit
holes (elderberry stem or shrub).
Sixteen percent, or a total of 71 new holes, were found
out of a total of 441 elderberry shrubs surveyed (all sites).
(5) A June 2002 to September 2004 survey of a 14.9-mi (24-km)
riparian corridor along the American River (lower American River Basin)
estimated occupancy rates of the valley elderberry longhorn beetle
ranging from 11.2 percent in lower alluvial plain, to 10.5 percent in
mid-elevation riparian, to 8.7 percent in upper riparian terrace, to
2.9 percent in non-riparian scrub habitat (Talley et al. 2007, pp. 25-
26).
[[Page 55887]]
Although the surveys outlined above are not identical in their
survey sites and sampling methods, the 16 percent abundance estimate
from 2010 (new exit holes for all sites surveyed) and the 21 percent
occupancy estimate from 2007 to 2008 (new exit holes from restoration
sites at the Sacramento River NWR) (Gilbart 2009, p. 40) align closely
with the 20 percent occupancy estimates for 1991 and 1997 presented in
Collinge et al. (2001, p. 105).
Based on a spatial analysis of valley elderberry longhorn beetle
populations in the Central Valley, Talley (2007, p. 1487) concluded
that the several hundred meter (hundreds of feet) distances observed
between local aggregations of the species supports a limited migration
distance for this species, as noted above (see Adult Behavior and
Ecology section). Talley (2007, p. 1487) further concluded that the
clustering of valley elderberry longhorn beetle populations at smaller
scales, tens of meters (tens of yards), is likely due to aggregation
behaviors of this species, and is not the result of: (1) Environmental
variables that occur at larger scales (less than 328 ft (less than 100
m), such as detection of elderberry plants (via plant volatiles); or
(2) distances relevant to mate attraction, which occur at even smaller
scales (few inches (centimeters)). However, additional studies of
movement patterns are needed in order to better describe these
observations of clustering and how these patterns relate to habitat
availability (see Adult Behavior and Ecology section above).
Further support for the clustering or aggregations pattern of
valley elderberry longhorn beetle populations can be found in
colonization and extinction rates developed by Collinge et al. (2001,
pp. 107-109) and Zisook (2007, p. 5). Collinge et al. (2001, p. 107)
found in a comparison of 1991 and 1997 surveys of both old and recent
exit holes in 14 drainages (65 sites, 111 groups of elderberry shrubs),
that two sites (6.5 percent) had long-term extinctions (i.e., no holes
found in 1997 and exit holes of any age observed in 1991) and four
sites (12.9 percent) had long-term colonizations (i.e., recent exit
holes observed in 1997, but no exit holes of any age found in 1991).
The comparative study also described short-term events (extinctions and
colonizations) based only on observations of recent exit holes for both
survey years. Nine sites (29 percent) exhibited short-term extinctions
and six sites (19.4 percent) had short-term colonizations (Collinge et
al. 2001, p. 108). One area (near Black Butte Lake; Stony Creek
drainage) that was occupied in 1991 was found to be unoccupied in the
1997 survey (Collinge et al. 2001, p. 108). The study concluded, based
on observations of only recent exit holes, that 77 percent of the sites
had the same occupancy status for the 2 years, with 23 percent of sites
showing some turnover between the two surveys (Collinge et al. 2001, p.
108). Zisook (2007, entire) presented an unpublished analysis of
extinction and colonization rates for the valley elderberry longhorn
beetle based on elderberry shrub sampling along a 14.9-mi (24-km)
section of the Lower American River. The analysis compares the 2000 to
2004 surveys to re-sampling efforts in 2005. In this study, extinction
was defined when no new (recent) holes were found on the same shrub in
2005 but where any age holes were recorded in 2000-2004; a colonization
event was recorded when there were no new holes found on a shrub in
2000-2004, but a recent hole was found on the same shrub in 2005
(Zisook 2007, p. 4). The analysis estimated an extinction rate of about
57 percent and a colonization rate of 19.1 percent for the population
sampled (Zisook 2007, p. 3).
These evaluations suggest that occupied sites of the valley
elderberry longhorn beetle tend to remain occupied (i.e., 77 percent),
but also exhibit variable long-term extinction rates (between 6.5 to 57
percent), and slightly higher short-term extinction rates. These
occupancy patterns result in a local clustering or aggregations of
regional, but patchy, populations within its range. We caution that
these extinction evaluations/results are from short-term studies at
different locations; therefore, these rates may not be suitable to
illustrate past or current conditions, especially for areas that have
not been recently surveyed for occupancy or colonization.
Rangewide surveys that utilize recent (new) exit holes as a measure
of valley elderberry longhorn beetle occupancy continue to be
challenging, given the species' low population densities and wide, but
discontinuous distribution. Monitoring methods for valley elderberry
longhorn beetle sites were evaluated from surveys conducted in 2010 at
10 watersheds (34 sites), from Shasta County to Kern County (Holyoak
and Graves 2010, entire). The study determined that an occupancy rate
of 1.5 percent of elderberry stems and a sample size of at least 600
elderberry stems for each watershed was needed to detect large (50 to
80 percent) declines in populations of the valley elderberry longhorn
beetle, a condition not met in many areas of the Central Valley
(Holyoak and Graves 2010, p. 2). However, using a sampling rate of 500
elderberry stems and 50 elderberry shrubs per watershed, the study
found that a good estimate of population density (based on the number
of new exit holes present) could be determined for 4 of the 10
watersheds surveyed (or 23 of 34 sites) (Holyoak and Graves 2010, p.
2). The authors recommended that a monitoring program for the valley
elderberry longhorn beetle in the Central Valley include a core group
of sites with the necessary number of elderberry stems to determine
occupancy, in combination with sampling other watershed locations for
presence or absence of new exit holes rather than abundance (Holyoak
and Graves 2010, p. 20).
Pheromone traps using aggregation pheromones (male-produced sex
attractants) (see, for example, Lacey et al. 2004, entire) may provide
an important survey tool for future distribution or taxonomic studies.
In April 2013, after the proposed rule published, field trials were
conducted at a riparian forest restoration site within the Sacramento
River NWR to test the efficacy of synthesized female valley elderberry
longhorn beetle sex pheromone (Arnold 2013, entire). Male valley
elderberry longhorn beetles were attracted almost exclusively to traps
baited with the (R)-desmolactone sex pheromone (33 of 34 males
captured); no female adult beetles were found in the traps (Arnold
2013, p. 4). This pheromone has also been found (under laboratory
conditions and in the field) to be an attractant for male California
elderberry longhorn beetles in San Bernardino County (Ray et al. 2012,
pp. 163-164). In both studies, no other cerambycid species were caught
in traps baited with either (R)- or (S)-desmolactone, which suggests
that (R)-desmolactone may be a pheromone specific to only these two
subspecies (Ray et al. 2012, p. 166; Arnold 2013, p. 4). Observations
of male beetles (confirmed through their sexually dimorphic
characteristics) attracted to these traps could also be used to confirm
the taxonomic identity of the valley elderberry longhorn beetle where
the two subspecies may co-occur (Arnold 2013, p. 4).
Vulnerability Factors
Collinge et al. (2001, p. 111) described the observed distribution
and abundance pattern of the valley elderberry longhorn beetle as an
unusual type of rarity, with small and localized populations where it
occurs within its presumed historical range. Rare species are generally
considered more vulnerable to extinction than
[[Page 55888]]
common species (Sodhi et al. 2009, p. 517). In general, three criteria
of rarity can be used to evaluate a species' vulnerability to
extinction risk when applied to its entire geographic range or to its
distribution and abundance in a specific area: (1) Narrow geographic
range; (2) specific habitat requirements; and (3) small population
size, although within a limited geographical range, a rare species may
be locally abundant (Primack 2006, pp. 155-156).
There is not always a consistent relationship between rarity and
extinction risk resulting from human influences, since the risk of
extinction is a function of more complex interrelationships between the
ecology of a species, its life history, and human activities (Pullin
2002, pp. 199-200). Nevertheless, vulnerability measures (e.g., Kattan
index (Kattan 1992, entire)) have been shown to be good proxies for
extinction risk, as observed for a study of beetles in an Italian
region of the Mediterranean (Fattorini 2013, p. 174).
The valley elderberry longhorn beetle exhibits several life-history
traits that may limit its distribution and population growth, which can
provide an extinction vulnerability profile. These attributes include:
(1) Restriction of the species to specific host plant taxa within
the Central Valley of California (i.e., specialized niche).
(2) Dependence on riparian ecosystems that have been reduced in
size and modified by human activities.
(3) Locally clustered populations with limited dispersal ability
that can be affected by natural and human disturbances.
All of these attributes, but particularly habitat specificity,
represent vulnerabilities for the valley elderberry longhorn beetle.
Vulnerability to extinction can be further complicated by the effects
of a changing climate. Numerous traits associated with climate change
vulnerability have been identified and consolidated into trait sets by
Foden et al. (2013, entire), based on a global assessment of bird,
amphibian, and coral species. Although the trait sets were not specific
to insect taxa, they are similar to variables considered in climate
change vulnerability assessment indices for vertebrate species (Bagne
et al. 2011, entire) and for plant and animal species (Glick et al.
2011, pp. 40-43, 48-50; Young et al. 2011, entire). The trait sets are
as follows: specialized habitat and/or microhabitat specialization;
narrow environmental tolerances; potential for disruption of
environmental triggers if they are important aspects in the life cycle;
disruption of important interspecific interactions; rarity; poor
dispersal potential due to low inherent dispersal ability and/or
extrinsic barriers to dispersal; and poor micro-evolutionary potential
due to low genetic diversity, long generation lengths and/or low
reproductive output (Foden et al. 2013, e65427). In addition to the
effect of any one trait, interactions between life history and spatial
traits also can influence extinction risk due to climate change
(Pearson et al. 2014, entire; Guisan 2014, entire).
Vulnerabilities may separately, or together, exacerbate the risk of
the threats described below in the Summary of Factors Affecting the
Species section.
Population Viability Analysis
Greenberg (2009, entire) developed a population viability analysis
(PVA) for the valley elderberry longhorn beetle using, in part,
demographic information provided from personal communications from
previous researchers. A metapopulation model was constructed to examine
how the spatial arrangement of habitat, dispersal range of adults, and
regulation of local populations (density dependence) based on age
structure affect the persistence of the valley elderberry longhorn
beetle. The results of this PVA model provide useful insights into how
the number and configuration of patches affect population persistence
and highlight the need to better understand migration distance between
patches (Greenberg 2009, p. 55). However, the predictions of population
persistence probabilities for this limited PVA analysis should be used
with caution given the incomplete empirical information and choice of
parameter values used in constructing this particular model. In
addition, this model did not incorporate potential effects related to
climate change. Thus, in this withdrawal, we do not provide additional
discussion of this PVA (and note this analysis has not been peer
reviewed); however, we anticipate using this modeling tool to help
direct future management options.
Summary
When we consider the low estimates of occupancy (Talley et al.
2007, pp. 25-26) and observed extinction and colonization patterns
(Collinge et al., 2001, pp. 107-108; Zisook 2007, p. 5), combined with
our re-evaluation of available data sets describing the distribution of
observations over the past 16 years (since 1997) (see Table 1, Figure
2), it is apparent that the distribution and abundance of the valley
elderberry longhorn beetle is clustered in regional aggregations and
locally uncommon or rare, which is consistent with our understanding of
its rare, patchy distribution pattern across its presumed historical
range in the Central Valley. Although evidence of occupancy (primarily
observations of exit holes) for the species has been documented in
additional locations to those recorded at the time of listing in 1980,
the best available data indicate this is a result of limited data
available at the time of listing and the subsequent surveys conducted
in: (1) The late 1980s (Jones and Stokes 1987, entire); (2) 1991 (Barr
1991, entire); (3) 1997 (Collinge et al. 2001, entire); (4) 2002-2005
(Talley 2014a, pers. comm.); and (5) 2010 (Holyoak and Graves 2010,
entire). These surveys have better defined the presumed historical
range of both elderberry longhorn beetles found in California (see also
Chemsak 2005, pp. 6-7; Figure 1, above). Additional comprehensive
surveys within the Central Valley, particularly locations of adult male
beetles, and the development of long-term population data sets for this
species are needed in order to provide a more complete assessment of
current population size and distribution.
As noted above, the valley elderberry longhorn beetle exhibits
several attributes that may limit its distribution and population size.
These include small numbers in localized populations, low estimates of
occupancy within its range (see Population Structure discussion),
limited dispersal, and dependence on two host plants for its entire
life cycle that are currently found within ecological communities that
have been reduced, fragmented, or otherwise degraded through human-
caused alterations. These attributes, particularly habitat specificity
(i.e., increased specialization), represent important vulnerabilities
for the valley elderberry longhorn beetle, that separately, or
together, may exacerbate any of the threats described below in our
five-factor analysis. Furthermore, environmental factors (e.g.,
additional habitat loss, unfavorable hydrological conditions) or other
types of stressors (e.g., predation) are likely to significantly
influence the species' vulnerability to extinction (see Summary of
Factors Affecting the Species discussions below).
Summary of Factors Affecting the Species
Section 4 of the Act and its implementing regulations (50 CFR part
424) set forth the procedures for adding species to the Federal Lists
of Endangered and Threatened Wildlife and Plants. A species may be
determined to be an endangered species
[[Page 55889]]
or threatened species because of one or more of the five factors
described in section 4(a)(1) of the Act: (A) The present or threatened
destruction, modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. Listing actions may be warranted
based on any of the above threat factors, singly or in combination.
Each of these factors is discussed below.
The five factors listed under section 4(a)(1) of the Act and their
analysis in relation to the valley elderberry longhorn beetle are
presented below. This analysis of threats requires an evaluation of
both the threats currently facing the species and the threats that
could potentially affect it in the foreseeable future. The Act defines
an endangered species as a species that is in danger of extinction
throughout all or a significant portion of its range (16 U.S.C.
1632(6)). A threatened species is one that is likely to become an
endangered species in the foreseeable future throughout all or a
significant portion of its range (16 U.S.C. 1632(20)).
In considering what factors might constitute threats, we must look
beyond the exposure of the species to a particular factor to evaluate
whether the species may respond to the factor in a way that causes
actual impacts to the species. If there is exposure to a factor and the
species responds negatively, the factor may be a threat, and during the
status review, we attempt to determine how significant a threat it is.
The threat is significant if it drives or contributes to the risk of
extinction of the species, such that the species warrants listing as
endangered or threatened as those terms are defined by the Act.
However, the identification of factors that could impact a species
negatively may not be sufficient to compel a finding that the species
warrants listing. The information must include evidence sufficient to
suggest that the potential threat is likely to materialize and that it
has the capacity (i.e., it should be of sufficient magnitude and
extent) to affect the species' status such that it meets the definition
of endangered or threatened under the Act.
The information presented in the five-factor analysis in this
withdrawal differs from that presented in the proposed rule.
Specifically, we restructured the five-factor analysis from our
proposed rule (77 FR 60238; October 2, 2012) to reflect our reanalysis
of threats, including additional and more detailed information (e.g.,
invasive plants in Factor A and pesticides under Factor E). We provide
a more extensive discussion of effects related to climate change in our
analysis of threats (under Factors A and E), including incorporation of
predictions from several regional climate models for the Central Valley
region. We also incorporate detailed results of several studies (e.g.,
metapopulation analysis) and use this information to evaluate the
current threats to the species. We also reiterate our discussion
contained in the proposed rule of small population size under Factor E,
but do not include in this withdrawal an evaluation of loss of
populations resulting from habitat fragmentation because we find that
additional data are needed to adequately or appropriately assess this
threat. Threats related to the effects of pruning, briefly mentioned in
our proposed rule under a Factor E threat (Human Use) (77 FR 60263;
October 2, 2012), are discussed in this withdrawal under Factor A.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
Historical Loss of Riparian Ecosystems
In our final rule listing the valley elderberry longhorn beetle as
threatened and designating critical habitat (45 FR 52803; August 8,
1980), we identified loss of habitat as a significant impact to the
valley elderberry longhorn beetle due to the threats of agriculture
conversion, levee construction, and stream channelization within its
``former'' range. In our proposed rule to delist the valley elderberry
longhorn beetle (77 FR 60250; October 2, 2012), we reviewed the
impacts, or potential impacts, of agricultural and urban development to
the species, primarily in the context of the loss of riparian
vegetation in the Central Valley, as well as impacts, or potential
impacts, related to the effects of levee construction and other flood
protection measures, and road maintenance and dust. In this withdrawal,
we provide a revised description of the impact of habitat loss to the
valley elderberry longhorn beetle based on our analysis of recently
mapped elderberry habitat within the Central Valley (Service 2014, GIS
analysis), in conjunction with new discussion related to the success of
restoration and mitigation sites intended to provide habitat for the
species. Similar to the proposed rule (77 FR 60250-60258; October 2,
2012), we also include separate discussions for Factor A threats that
may result in the destruction or modification of habitat (i.e., levee
and flood protection infrastructure, road and trail use and
maintenance, pruning, effects of climate change, and invasive plants).
Additionally, we note that pruning was only briefly discussed in the
proposed rule under Factor E--Human Use; we have expanded that
discussion and are now including it under Factor A because we consider
pruning activities to be a potential threat related to destruction or
modification of habitat.
Loss of habitat is the leading cause of species extinction (Pimm
and Raven 2000, p. 843). Insects that are considered specialized plant-
feeders or those restricted to one (monophagous) or a few
(oligophagous) plant taxa are especially vulnerable to habitat loss, as
their survival may depend on their ability to make improbable or
impossible host plant shifts (Fonseca 2009, p. 1508). The valley
elderberry longhorn beetle can be considered an oligophage, and is
dependent exclusively on two elderberry taxa (see Habitat section) for
all aspects of its life history.
Prior to settlement by Anglo-Americans, the Central Valley
contained extensive riparian plant communities along unaltered river
systems, including riparian forests comprised primarily of sycamore,
cottonwood, willow, and oak trees and a thick understory of shrubs,
including elderberry (Roberts et al. 1980, pp. 7, 10). A detailed
summary of historical observations (circa 1800s) of riparian forests
along the Sacramento River is presented in Thompson (1961, pp. 301-
307). The majority of this ``timber belt'' was cut as early as 1868
(Tehama County) to supply fuel and timber (e.g., fencing) as the valley
was settled (Thompson 1961, p. 311). In addition to supplying lumber to
a largely treeless valley, the trees that comprised the historic
riparian forests of the Sacramento Valley (and likely other parts of
the Central Valley) provided reinforcement to river banks and greater
stability to stream channels (Thompson 1961, p. 315). These forests
also served as windbreaks, reducing the effects of wind and
evapotranspiration, while providing important wildlife habitat
(Thompson 1961, p. 315).
Much of the historically occurring riparian forests were lost in
the Central Valley prior to the listing of the valley elderberry
longhorn beetle (see summary for the Sacramento Valley by Thompson
1961, pp. 310-315). Katibah (1984, pp. 27-28) estimated approximately
102,000 ac (41,300 ha) of riparian forest remained in the Central
Valley in 1984, a reduction of about 89 percent from an estimated total
of 921,600 ac (373,100 ha) of pre-
[[Page 55890]]
settlement riparian forest area. A Central Valley mapping effort,
initiated in 1978 with legislation that provided funding to study the
riparian resources of the Central Valley and desert (Riparian Mapping
Team 1979, p. 1), presented an initial evaluation of the condition of
riparian vegetation using remote sensing methods in 1981 (Katibah et
al. 1981, entire; see also Katibah et al. 1984, entire), or 1 year
after the listing of the valley elderberry longhorn beetle as
threatened (45 FR 52803; August 8, 1980). This assessment used a
qualitative condition index for each sample site and concluded that the
conditions of riparian systems at that time were either disturbed,
degraded, or severely degraded (85 percent), with 15 percent considered
to be in good or ``apparently unaltered'' condition (Katibah et al.
1981, p. 245). About 34 percent of riparian systems were considered to
be recovering or stable (Katibah et al. 1981, p. 245). Adjacent land
uses (primarily agriculture), stream channelization, and livestock
grazing were reported as important negative influences on riparian
systems (Katibah et al. 1981, p. 244). Specifically, artificial levees,
river channelization, dams, and water diversions were identified as
factors in reducing the original riparian forests to the remnant
habitat described at that time for the Central Valley (Katibah 1984, p.
28).
Since that initial assessment, the Central Valley Historic Mapping
Project has refined their estimates of historic natural vegetation for
the Central Valley and has developed an accessible GIS-based analysis
of vegetation changes over the past 100 years (Geographical Information
Center (GIC) 2003, entire). Four maps (pre-1900, 1945, 1960, 1995) were
created to illustrate eras in which significant land use changes
occurred in the Central Valley, such as Anglo-American settlement and
water diversion projects (GIC 2003, p. 3). Using a variety of methods
and sources, this analysis estimated that 1,021,584 ac (413,420 ha) of
riparian vegetation were found within the valley pre-1900, and about
132,586 ac (53,656 ha) of riparian vegetation remained in the Greater
Central Valley in 2000, a reduction of 87 percent (GIC 2003, p. 14).
Based on results from a 2003 survey of 16 waterways (47 plots) in
the Sacramento Valley (i.e., upper portion of the extant occurrences
observed for the valley elderberry longhorn beetle), Hunter et al.
(2003, p. 41) described the riparian vegetation along these waterways
as ``relatively narrow bands with an open, discontinuous canopy.'' This
survey described many of these riparian zones as disturbed, with
evidence of channel incision, overbank flows, and dumping of trimmed/
cut tree branches, and they frequently contained some type of
infrastructure (Hunter et al. 2003, p. 41). Surrounding land use
(within 820 ft (250 m)) was characterized as 43 percent natural, 38
percent agricultural, and 18 percent developed; only 17 percent of the
plots were surrounded entirely by natural vegetation (Hunter et al.
2003, p. 41).
The Sacramento River represents one river system in the Central
Valley within the northern range of the valley elderberry longhorn
beetle that has been severely degraded through channelization, bank
protection (e.g., levees and riprap), and effects related to the
construction of the Shasta Dam and other foothill storage reservoirs
(Golet et al. 2013, p. 3). Natural, but fragmented, habitats (e.g.,
riparian, grasslands, sloughs, and valley oak woodlands) remain along
the Sacramento River (Golet et al. 2013, p. 5). The middle section of
the river (Red Bluff to Colusa) has been the focus of restoration
efforts following the passage of State legislation in 1986 (Senate Bill
1086), which mandated the development of a management plan to protect,
restore, and enhance riparian vegetation along the river (Sacramento
River Conservation Area Forum 2003, p. v). A comprehensive evaluation
of the success of these efforts indicated that, while progress has been
made in achieving goals related to plant species and communities
(including an increase in elderberry shrubs) and some wildlife taxa,
progress towards restoring stream flows and natural floodplain and
flood processes has been poor (Golet et al. 2013, pp. 19-21). In
addition, this evaluation found that the status of natural riverine
habitats in this portion of the Sacramento River was, in general, poor
and declining, which was attributed to continued human alterations that
constrain the river's hydrologic and geomorphic processes (Golet et al.
2013, p. 22). One of the major factors identified as responsible for
the continued degradation of riverine habitats was the installation of
riprap, which the study indicated has been steadily increasing along
the Sacramento River since the 1930s (Golet et al. 2013, p. 22).
Assessment of Current Elderberry Habitat Relative to Metapopulation
Structure of the Valley Elderberry Longhorn Beetle
As part of the Central Valley Flood protection efforts, Chico State
University, the GIC, and CDFW's Vegetation Classification and Mapping
Program have developed both a medium-scale and fine-scale dataset for
riparian vegetation in the Central Valley (CDWR 2012b, pp. 5-1--5-9).
The medium-scale map illustrates the extent of riparian vegetation
using about 20 general vegetation classes (see CDFW 2014a and Central
Valley Riparian Mapping Project (CVRMP) 2014 for Web site addresses).
The fine-scale version provides a more detailed plant community
resolution such that vegetation associations and alliances containing a
range of probability of elderberry shrub occurrence within those
associations and alliances can be identified; this map is nearly
complete for the entire Central Valley. Both maps were created using
imagery from the U.S. Department of Agriculture (USDA) National
Agriculture Imagery Program (NAIP) from 2009 and current field sampling
(USDA NAIP 2014).
In our proposed rule, we presented an estimate of 46,936 ac (18,994
ha) of protected riparian vegetation, which we stated may or may not
contain elderberry shrubs (77 FR 60256, October 2, 2012). Rather than
infer the amount of elderberry habitat from this gross estimate of
riparian vegetation (which is what was presented in the proposed rule),
we instead use the mapped Sambucus nigra Alliances (described as blue
elderberry) defined in the 2009 Central Valley fine-scale riparian
vegetation data set (CDFW and GIC 2013) to better define the current
extent of elderberry habitat in the Central Valley. We also assess the
size of the defined polygons of elderberry and their location in the
Central Valley relative to the presumed metapopulation structure
identified for the valley elderberry longhorn beetle (Talley et al.
2006a, pp. 10-11). We acknowledge that elderberry shrubs likely occur
in varying degrees of cover and constancy within other mapped
vegetation alliances, but we are unable to accurately determine the
extent and location of these areas based on the spatial information in
these data sets and descriptions provided in Buck-Diaz et al. (2012,
Appendix 4) for these other plant alliances; thus, our estimate of
elderberry habitat is likely to be conservative.
The CDFW/GIC data set contains 39 blue elderberry polygons (124 ac
(50 ha)) located within our presumed historical range for the valley
elderberry longhorn beetle (see Figure 1). Using the metapopulation
spatial parameters presented in Talley et al. (2006a, p. 11) (i.e.,
extent of 1,968-2,625 ft (600-800 m) defined as a cluster), we
identified potential metapopulation clusters in our data set. We first
determined which of the mapped elderberry polygons were less than 1,968
ft (600 m) from their
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nearest neighbor (16 of the 39 polygons), and merged these together to
redefine these larger polygons. This resulted in 16 polygons merging
into 4, for a new total of 27 mapped elderberry polygons. We then
conducted a ``bounding containers'' GIS analysis (Service 2014, GIS
analysis) for these 27 polygons to identify those (now rectangular)
polygons where the diagonal was at least 1,968 ft (600 m), as this is
the minimum distance (i.e., 1,968-2,625 ft (600-800 m)) to meet Talley
et al.'s (2006a, p. 11) criteria as a metapopulation cluster.
Based on this analysis, 3 of the 27 polygons had a longest length
(i.e., diagonal) greater than 1,968 ft (600 m) and, therefore, could be
considered as metapopulation clusters supporting a regional population
of the valley elderberry longhorn beetle (Talley et al. 2006a, p. 11).
These three elderberry clusters were located: (1) Along the Cosumnes
River; (2) south of Marysville at the southern end of Clark's Slough;
and (3) near an unnamed tributary of the Yuba River. All other mapped
elderberry polygons were less than 1,968 ft (600 m) in extent.
We then evaluated the location of exit holes or beetle observations
from 1997 to 2012 (Figure 2) relative to all 39 elderberry polygons.
Based on the level of precision of the mapped locations, we find that
38 survey points out of a total of 1,422 (or less than 3 percent) were
located within the 39 elderberry polygons.
These results could be interpreted in several ways (or in
combination): (1) Relatively few stands of elderberry habitat remain
within the Central Valley and their small size (average of 2.9 ac (1.17
ha)) and spatial arrangement may be insufficient to support the
metapopulation structure defined for the valley elderberry longhorn
beetle (Talley et al. 2006a, p. 11); (2) areas within the species'
range have not been adequately surveyed; (3) the mapping methods used
did not identify all areas of elderberry habitat; or (4) the parameters
that define the presumed metapopulation structure or the life-history
requirements for the species need to be reevaluated. Occupancy surveys
within the mapped elderberry polygons are needed to assess these or
other possibilities.
Occupancy of Restoration and Mitigation Sites
As noted in our proposed rule (77 FR 60256-60258; October 2, 2012),
efforts to establish areas of riparian vegetation (though not
necessarily elderberry habitat) through restoration projects or
mitigation requirements under the Act have been conducted in order to
provide additional areas of habitat for the species. Rather than
present rough estimates of the number of acres of protected riparian
vegetation, as was done in the proposed rule, we are instead providing
in this document a review of assessments of these areas conducted in
the past 10 years. We modified this discussion from what was presented
in the proposed rule based on comments received, as well as evaluated
the success of some of these restoration and mitigation sites based on
estimates of occupancy of the valley elderberry longhorn beetle.
An evaluation of restoration of riparian vegetation along 106 river
km (66 river mi) of the Sacramento River included an assessment of
valley elderberry longhorn beetle occupancy (exit holes) at five
restoration sites (surveys conducted in 2003) (Golet et al. 2008, pp.
7-8). Older restoration sites (greater than 8 years) had a larger
percentage (approximately 10 to 21 percent) of shrubs with exit holes
(River Partners 2004, p. 3), likely due to the size class differential
and observed preferences of the valley elderberry longhorn beetle for
larger stem sizes.
A limited evaluation of (blue) elderberry and other riparian
planting efforts at 30 mitigation sites over approximately 485 ac (196
ha) in the Central Valley (from Tehama County to Madera County) was
undertaken in 2005 and 2006 to evaluate their success in establishing
occupancy of the valley elderberry longhorn beetles (Holyoak and Koch-
Munz 2008, entire). A spatial analysis of exit holes of all ages
determined that the valley elderberry longhorn beetle was present at 16
of the 30 mitigation sites (53 percent) (Holyoak and Koch-Munz 2008, p.
447). As noted above, the abundance of the valley elderberry longhorn
beetle per elderberry shrub and per stem in this study was also found
to be positively related to the age of the mitigation site (Holyoak and
Koch-Munz 2008, p. 449).
Holyoak et al. (2010, entire) reviewed publicly available
mitigation monitoring reports (total of 60) to evaluate the success of
mitigation sites in conserving the valley elderberry longhorn beetle,
as measured by the survival of elderberry plants and how frequently the
species colonized mitigation sites. Although this review noted that
many expected mitigation reports were missing and thus highlighted the
need for better data management practices, they found that the survival
of both elderberry seedlings and transplants was highly variable and
declined over time after planting (Holyoak et al. 2010, p. 48).
Specifically, by year seven, 57 to 64 percent of transplanted
elderberry survived, with 71 percent survival of seedlings (Holyoak et
al. 2010, pp. 48-49). The study also found that the mitigation site
(e.g., location, age) accounted for 25 percent of the variability in
proportion of seedlings that survived, which suggested that the
mitigation site choice can have an important effect on the ability to
establish elderberry plants (Holyoak et al. 2010, p. 49).
Summary of Available Habitat
There has been a significant loss and degradation of riparian and
other natural habitats in the presumed historical range of the valley
elderberry longhorn beetle, much of which occurred prior to the listing
of the species. In our proposed rule, we noted that we could not
accurately determine the potential lost historical range of valley
elderberry longhorn beetle habitat, and that coarse estimates have been
attempted based on historical losses of riparian vegetation (77 FR
60241; October 2, 2012). Rather than infer lost elderberry habitat from
estimates of lost riparian forests, we include here a summary of
current elderberry habitat (based on 2009 imagery) mapped within the
Central Valley, and assess how these mapped areas conform to the
metapopulation structure of the valley elderberry longhorn beetle as
defined by species' experts. This preliminary assessment indicates that
elderberry habitat remains limited in extent within the Central Valley
and may not support the spatial requirements of sustainable
metapopulations presumed for the valley elderberry longhorn beetle. We
note that the results of this assessment do not allow us to draw
definitive conclusions on the valley elderberry longhorn beetle
metapopulation given the limitations of these data.
Occupancy rates of valley elderberry longhorn beetle in riparian
vegetation at some mitigation sites provide some indication that the
species has been successful in colonizing these areas; however,
monitoring is incomplete in both these areas and within restoration
sites. Given the life-history traits defined for the valley elderberry
longhorn beetle, as discussed in the Background section (i.e., habitat
specialist, with limited mobility and a short adult life span, and low
local numbers within a population structure), and the limited and
fragmented habitat within its current range, we reaffirm our conclusion
in the proposed rule that loss of habitat continues to remain a threat
to the species. For this withdrawal, we reevaluated this threat in
combination with the other threats
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described below and determined threats to the species and its habitat
have not been reduced such that delisting is appropriate.
Levee and Flood Protection Infrastructure
As described in our proposed rule, the Central Valley contains an
extensive flood protection system, much of which predates the listing
of the valley elderberry longhorn beetle (77 FR 60251; October 2,
2012). The (California) State Plan of Flood Control (SPFC) represents a
portion of the Central Valley flood management system for which the
State has special responsibilities, as described in the California
Water Code Section 9110(f) (CDWR 2011, pp. 1-7). The SPFC Descriptive
Document provides a detailed inventory and description of the levees
(approximately 1,600 mi (2,575 km)), weirs, bypass channels, pumps,
dams, and other structures included in the SPFC (CDWR 2010, entire).
This flood protection system comprises federally and State-authorized
projects for which the Central Valley Flood Protection Board or the
California Department of Water Resources (CDWR) has provided assurances
of cooperation to the Federal Government. Other flood protection
facilities in the Sacramento River and San Joaquin River watersheds
that are not covered by these assurances are not part of this State-
Federal system (CDWR 2010, p. Guide-1). Thus, the SPFC represents a
portion of the larger system that provides flood protection for the
Central Valley (CDWR 2010, p. Guide-1).
As noted in the proposed rule, ongoing and future maintenance of
these flood protection elements may result in losses of riparian
vegetation and elderberry shrubs in addition to what has been
historically lost; however, we stated that we had no estimate of the
acreage of riparian vegetation (or elderberry shrubs within these
areas) on the flood protection levees or lands that provide additional
flood facilities (77 FR 60252; October 2, 2012).
We also described in our proposed rule new flood control system
maintenance requirements being implemented by the U.S. Army Corps of
Engineers (Corps), specifically, the 2009 Guidelines for Landscape
Planting and Vegetation Management at Levees, Floodwalls, Embankment
Dams, and Appurtenant Structures (Engineering Technical Letter (ETL)
1110-2-571) (Corps 2009, entire). In general, this ETL establishes a
vegetation-free zone for the top of all levees and levee slopes, and 15
ft (4.5 m) on both the water and land sides of levees (Corps 2009, pp.
2-1--2-2, 6-1--6-2), which are practices that could eliminate occupied
or unoccupied elderberry shrubs. On April 30, 2014, the Corps issued a
new Guidelines for Landscape Planting and Vegetation Management at
Levees, Floodwalls, Embankment Dams, and Appurtenant Structures (ETL)
1110-2-583), superseding the 2009 ETL (Corps 2014, entire). The 2014
guidelines maintains the previous ETL guidelines of a vegetation-free
zone for the top of all levees and levee slopes, and 15 ft (4.5 m) on
both the water and land sides of levees (Corps 2014, pp. 2-1--2-3, A2-
A3).
At the time of our proposed rule, we indicated that the final
policy guidance for the issuance of variances from the ETL vegetation
standards for levees and floodwalls had not been released; therefore,
we were unable to determine if this variance process would have an
effect on levee segments containing woody vegetation (77 FR 60253;
October 2, 2012). In this document, we provide an update to our
discussion of this threat and include additional information relative
to policies being implemented by CDWR to address levee vegetation
management.
On February 17, 2012 (77 FR 9637), the Corps issued a notice for a
Policy Guidance Letter (PGL) outlining the process for requesting this
variance. The PGL applies to levees within the Corps' Levee Safety
Program including those operated or maintained by the Corps, those that
are federally authorized and locally operated and maintained, and those
locally constructed and locally operated and maintained, but associated
with the Corps' Rehabilitation and Inspection Program (77 FR 9637;
February 17, 2012). However, in practice, the variance process has been
described as time intensive and costly, even for just a few miles of
levee (Qualley 2014, pers. comm.). Therefore, securing variances for
the protection of elderberry shrubs or other riparian vegetation found
on levees under the Corps' jurisdiction may not be a practical option
at this time.
The CDWR's Central Valley Flood Protection Plan (CVFPP) includes a
Levee Vegetation Management Strategy to address the vegetation-free
guidelines set out within the Corps' ETL (CDWR 2011, pp. 4-13--4-16).
The approach states that it ``reflects a flexible and adaptive
management strategy that meets public safety goals, and protects and
enhances sensitive habitats in the Central Valley'' (CDWR 2012a, p. 1).
Specifically, new levees would be constructed and managed consistent
with the new policy, however, those levees with ``legacy'' trees would
be managed to allow existing large trees and other woody vegetation to
continue their normal life cycle unless they were considered to be an
unacceptable threat to levee integrity (CDWR 2012a, p. 1). The CVFPP
strategy also allows for the retention of waterside vegetation below
the vegetation management zone (generally beyond the 20-ft (6.1-m)
slope length from the levee crown) (CDWR 2011, p. 4-14). This CVFPP
strategy is likely to provide, at least in the short term, a more
protective mechanism for riparian vegetation, including elderberry
shrubs, than the variance process outlined in the PGL (which as stated
above is intensive, costly, and likely not practical).
The potential for the Corps to issue variances under the ETL
guidance along with CDWR's strategy to address levee vegetation
management do not change CDWR's obligation to meet Federal and State
law with regard to valley elderberry longhorn beetle habitat and
riparian vegetation (see Factor D) (Qualley 2014, pers. comm.).
The Water Resources Reform and Development Act (WRRDA) of 2014
(Pub. L. 113-121) contains a vegetation management policy provision
(Title III, Subtitle B-Levee Safety, Section 3013) that requires the
Corps to conduct a comprehensive review of its policy guidelines (i.e.,
ETL 1110-2-583 and PGL for requesting variances, as noted above) for
management of vegetation on levees in consultation with other
applicable Federal agencies, representatives of State, regional, local,
and tribal governments, appropriate nongovernmental organizations, and
the public. This may allow for more appropriate regional variances from
the single national ETL standard currently outlined in the Corps'
vegetation management policies. The WRRDA 2014 vegetation management
policy provision also includes a requirement for the Corps to solicit
and consider the views of independent experts on the engineering,
environmental, and institutional considerations underlying the
guidelines.
In summary, as we concluded in our proposed rule (77 FR 60254;
October 2, 2012) and reaffirm in this document, levee vegetation
management actions are expected to continue to impact elderberry shrubs
within the range of the valley elderberry longhorn beetle. Threats
related to removal of elderberry vegetation may be reduced in the
future in some locations within the Central Valley based on revisions
to the Corps' vegetation management policies as outlined in the 2014
WRRDA. Long-
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term impacts of levee vegetation management actions may be offset with
implementation of mitigation (e.g., establishment of mitigation sites
or restrictions on pruning); however, as described above and in our
Background section, the success of mitigation sites in establishing
occupancy of the valley elderberry longhorn beetle has not been fully
evaluated, so its success is currently indeterminable.
Road and Trail Use and Their Maintenance
Road and trail use and their maintenance and the effects of dust
related to these activities are identified in our Recovery Plan and in
Biological Opinions as threats to the quality of valley elderberry
longhorn beetle habitat (Service 1984, p. 41; Service 2002, p. 3). As
described in our proposed rule, machinery used in road maintenance
activities can crush adjacent elderberry shrubs, or cause indirect
stress to plants (e.g., leaf shading, blocked stomata) through the
raising of dust (77 FR 60254; October 2, 2012). Similarly, dust can
originate from access roads and recreational trails within riparian
corridors where elderberry habitat is often found (Talley et al. 2006b,
p. 648). Dust could also affect the survival and behavior of the valley
elderberry longhorn beetle by smothering adults or larvae, disrupting
chemical cues important for mating and detecting host plants, or
creating unpalatable leaves or flowers (Talley et al. 2006b, p. 649).
As noted in our proposed rule (77 FR 60254, October 2, 2012), a
rangewide study on the effects of dust to the valley elderberry
longhorn beetle or its host plant has not been conducted. To better
address this topic, we provide a summary of a study that evaluated dust
effects that was not described in the proposed rule.
A study to test the effects of dust from dirt trails relative to
paved trails was conducted along the American River Parkway in 2003
(Talley et al. 2006b, entire). The study found similar dust settlement
rates and leaf dust accumulation along dirt and paved trails, but when
data from all sites were pooled, elderberry plants tended to be more
stressed (e.g., shorter plants, lower percent leaf water content,
thicker leaves, higher percentage of dead stems) near dirt trails than
paved surfaces (Talley et al. 2006b, p. 651), a result the authors
attributed to factors other than dust (Talley et al. 2006b, p. 653).
Talley et al. (2006b, p. 653) concluded the difference in elderberry
characteristics near dirt trails was likely due to reduced water
availability (less surface runoff than near paved surfaces) and less
soil water (further distances from water sources). The authors also
suggested that the effects of dust may be more significant over larger
spatial scales given the variability of dust levels among and between
the sites studied (Talley et al. 2006b, p. 653).
The study also looked at the relationships between the presence or
absence of valley elderberry longhorn beetle and distances from dirt
and paved surfaces. The authors found that the presence of new and 1-
year-old valley elderberry longhorn beetle exit holes was independent
of both trail location and surface type (Talley et al. 2006b, p. 654).
Further, the study noted that valley elderberry longhorn beetle exit
holes were found at all sites despite higher dust levels at some study
sites, and concluded that levels of dust from dirt trails, paved
trails, and access roads did not have a negative association with the
presence of the species, despite the variability in condition of
elderberry plants (Talley et al. 2006b, pp. 654-655).
In another study, Talley and Holyoak (2009, entire) evaluated how
the proximity to highways and highway construction activities affects
the occupancy of the valley elderberry longhorn beetle and condition of
elderberry shrubs. Field surveys from 2006 to 2008 were used to
evaluate the effects of particulates, pollutants, and noise along
portions of several highways in the northern Central Valley of
California (Talley and Holyoak 2009, pp. 2-3). The study included a
laboratory analysis of effects to elderberry leaves (i.e., dust levels,
leaf area, carbon to nitrogen ratios, and exhaust elements) and an
evaluation of statistical relationships between the distances from
either a construction site or highway edge and both dust accumulation
rates and elderberry characteristics (Talley and Holyoak 2009, p. 4).
The study found no effect of the proximity of highways on dust
accumulations and few effects related to potentially toxic elements in
elderberry leaves (Talley and Holyoak 2009, p. 9). Noise levels were
found to decrease with distance from highways; however, noise levels
were similar at sites located immediately adjacent to highways, despite
differences in traffic volume (Talley and Holyoak 2009, p. 6).
The researchers determined that the type of habitat and
availability of elderberry shrubs were the primary factors influencing
the likelihood of the presence of either recent or total (recent and
old) valley elderberry longhorn beetle exit holes; no relationships
were observed between distance from highways and distribution of exit
holes (Talley and Holyoak 2009, p. 6). However, the amount of available
elderberry habitat was found to be significantly lower along roadsides,
and elderberry stem densities were smaller in sites immediately
adjacent to highways when compared to riparian or control sites, or
compared to remnant riparian and non-riparian scrub areas (Talley and
Holyoak 2009, pp. 8-9). This was attributed to right-of-way management
activities (e.g., mowing, pruning) rather than a direct stress effect
of being located adjacent to highways (Talley and Holyoak 2009, p. 9).
These findings reinforce results of other studies in which a range
of both elderberry quality and quantity characteristics have been found
to influence the presence and abundance of the valley elderberry
longhorn beetle (Talley and Holyoak 2009, p. 8; see Habitat discussion
above in Background section). The authors of the highway study noted
the need for additional larger scale studies as well as controlled
experimental studies to test specific effects on valley elderberry
longhorn beetle survival (e.g., an evaluation of whether roadside
patches act as population sinks that attract individuals into areas
that are not able to sustain populations (Pulliam 1988, pp. 658-660))
(Talley and Holyoak 2009, p. 11).
In summary, threats related to road and trail uses, and the effects
of dust, do not represent significant impacts to the valley elderberry
longhorn beetle. However, removal of elderberry shrubs along the
roadways (for right-of-way management activities) is a more important
factor and is discussed in more detail below (see discussion under
Pruning).
Pruning
In our proposed rule, we briefly discussed pruning as part of a
Factor E threat, termed Human Use (77 FR 60263; October 2, 2012).
Because we consider pruning activities to be a potential threat related
to destruction or modification of habitat, we discuss pruning as a
separate Factor A threat and include results from a study that was not
discussed in the proposed rule. Pruning or trimming of elderberry
shrubs for highway or trail maintenance, or other purposes, is a common
activity within the presumed extant occurrences of the valley
elderberry longhorn beetle. Talley and Holyoak (2009, entire) conducted
an experimental study to measure the effects of pruning of elderberry
shrubs on the valley elderberry longhorn beetle and its host plant. Two
experimental techniques (pruning and topping) were used within
elderberry habitat found along portions
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of the American River Parkway (Talley and Holyoak 2009, p. 29). The
pruning experiment was designed to mimic the trimming (i.e., 50 percent
of all branches 1 in (2.5 cm) or less in diameter) of elderberry shrubs
that overhang roads and trails, while the topping experiment was
designed to evaluate the removal of the top 3.28 ft (1 m) of a shrub or
group of shrubs that often occurs beneath power lines and overhead
obstructions (Talley and Holyoak 2009, p. 30). The experiments used
measures of elderberry survival, growth, and condition as well as the
presence and abundance of new valley elderberry longhorn beetle exit
holes (Talley and Holyoak 2009, p. 30). The study found no ``short-
term'' (2-4 weeks) changes in the survival, growth, or condition in
response to the two experiments (Talley and Holyoak 2009, p. 32).
In addition, laboratory analyses to evaluate nutrient and defense
chemical content indicated that neither experimental treatment had
detectable effects on elderberry nutrition (Talley and Holyoak 2009, p.
32). The study also found that neither colonization nor loss of valley
elderberry longhorn beetles from elderberry shrubs was affected by
pruning or topping experiments; that is, the declines and increases in
occupied shrubs was independent of trimming, and, if anything, was
likely related to the initial presence of the species (Talley and
Holyoak 2009, p. 31). The only negative effect reported from this
experimental study was a temporary loss of habitat from the removal of
stems, but these stems regrew, on average, within 3 to 4 years (Talley
and Holyoak 2009, p. 33).
Based on the potential impacts from pruning described in the
proposed rule, the pruning of elderberry shrubs, when conducted in
accordance with the findings of experimental studies presented by
Talley and Holyoak (2009, pp. 29-33), will likely have temporary
impacts to the valley elderberry longhorn beetle. Additional
experimental studies of the effects of pruning (e.g., at mitigation or
restoration sites) would provide a more complete evaluation of the
magnitude of this threat to the species.
Effects Related to Climate Change
In our proposed rule, we discussed the effects of climate change
under Factors A and E (77 FR 60254-60255, 60262; October 2, 2012). We
stated that we did not have information that would allow us to make
meaningful predictions of the effects of changes in temperature and
precipitation patterns relative to potential changes in elderberry
habitat (77 FR 60255; October 2, 2012). We concluded in Factor E that
climate change was not a significant factor affecting the persistence
of the valley elderberry longhorn beetle (77 FR 60262; October 2,
2012).
In this withdrawal, we discuss threats related to the effects of
climate change in Factors A and E. In Factor A, we provide a more
robust discussion of both observed and predicted effects to
hydrological patterns related to climate change effects for the Central
Valley based on state-wide and regional probabilistic estimates of
temperature and precipitation changes for California (using downscaled
data from both global circulation models and nested regional climate
models), and also present results of climate assessment tools to
illustrate these predicted effects. In Factor E, we discuss the effects
of climate change related to the survivorship and reproductive success
of the valley elderberry longhorn beetle.
Our analyses under the Act include consideration of observed or
likely environmental changes resulting from ongoing and projected
changes in climate. As defined by the Intergovernmental Panel on
Climate Change (IPCC), the term ``climate'' refers to the mean and
variability of different types of weather conditions over time, with 30
years being a typical period for such measurements, although shorter or
longer periods also may be used (IPCC 2013a, p. 1450). The term
``climate change'' thus refers to a change in the mean or the
variability of relevant properties, which persists for an extended
period, typically decades or longer, due to natural conditions (e.g.,
solar cycles) or human-caused changes in the composition of atmosphere
or in land use (IPCC 2013a, p. 1450).
Scientific measurements spanning several decades demonstrate that
changes in climate are occurring. In particular, warming of the climate
system is unequivocal and many of the observed changes in the last 60
years are unprecedented over decades to millennia (IPCC 2013b, p. 4).
The current rate of climate change may be as fast as any extended
warming period over the past 65 million years and is projected to
accelerate in the next 30 to 80 years (National Research Council 2013,
p. 5). Thus, rapid climate change is adding to other sources of
extinction pressures, such as land use and invasive species, which will
likely place extinction rates in this era among just a handful of the
severe biodiversity crises observed in Earth's geological record
(American Association for the Advancement of Sciences (AAAS) 2014, p.
17).
Examples of various other observed and projected changes in climate
and associated effects and risks, and the bases for them, are provided
for global and regional scales in recent reports issued by the IPCC
(2013c, 2014), and similar types of information for the United States
and regions within it can be found in the National Climate Assessment
(Melillo et al. 2014, entire).
Results of scientific analyses presented by the IPCC show that most
of the observed increase in global average temperature since the mid-
20th century cannot be explained by natural variability in climate and
is ``extremely likely'' (defined by the IPCC as 95 to 100 percent
likelihood) due to the observed increase in greenhouse gas (GHG)
concentrations in the atmosphere as a result of human activities,
particularly carbon dioxide emissions from fossil fuel use (IPCC 2013b,
p. 17 and related citations).
Scientists use a variety of climate models, which include
consideration of natural processes and variability, as well as various
scenarios of potential levels and timing of GHG emissions, to evaluate
the causes of changes already observed and to project future changes in
temperature and other climate conditions. Model results yield very
similar projections of average global warming until about 2030, and
thereafter the magnitude and rate of warming vary through the end of
the Century depending on the assumptions about population levels,
emissions of GHGs, and other factors that influence climate change.
Thus, absent extremely rapid stabilization of GHGs at a global level,
there is strong scientific support for projections that warming will
continue through the 21st century, and that the magnitude and rate of
change will be influenced substantially by human actions regarding GHG
emissions (IPCC 2013b, 2014; entire).
Global climate projections are informative, and, in some cases, the
only or the best scientific information available for us to use.
However, projected changes in climate and related impacts can vary
substantially across and within different regions of the world (e.g.,
IPCC 2013c, 2014; entire) and within the United States (Melillo et al.
2014; entire). Therefore, we use ``downscaled'' projections when they
are available and have been developed through appropriate scientific
procedures, because such projections provide higher resolution
information that is more relevant to spatial scales used for analyses
of a given species (see Glick et al. 2011, pp. 58-61, for a discussion
of downscaling).
[[Page 55895]]
Various changes in climate may have direct or indirect effects on
species. These may be positive, neutral, or negative, and they may
change over time, depending on the species and other relevant
considerations, such as interactions of climate with other variables
such as habitat fragmentation (for examples, see Franco et al. 2006;
Forister et al. 2010; Galbraith et al. 2010; Chen et al. 2011;
Bertelsmeier et al. 2013, entire). In addition to considering
individual species, scientists are evaluating potential climate change-
related impacts to, and responses of, ecological systems, habitat
conditions, and groups of species (e.g., Deutsch et al. 2008; Berg et
al. 2010; Euskirchen et al. 2009; McKechnie and Wolf 2010; Sinervo et
al. 2010; Beaumont et al. 2011; McKelvey et al. 2011; Rogers and
Schindler 2011; Bellard et al. 2012).
As an example, Hickling et al. (2006, entire) analyzed the changes
in distributions of groups of vertebrates and invertebrates, including
longhorn beetles, in Great Britain to determine whether range shifts
(both in latitude and elevation) have occurred over an approximately
25-year time span. For 11 species of longhorn beetles, the study found
that, for grid squares (6.2 mi (10 km)) considered to be well-recorded
(i.e., those that had at least 10 percent of that group recorded
present in both study time periods), there was an average shift
northward of 27 mi (43 km) and an average elevational shift of 86 ft
(26 m) from 1960-1970 to 1985-1995 (Hickling et al. 2006, pp. 451-453).
The authors stressed the importance of recognizing that observed
distribution shifts due to climate change are occurring concurrently
with changes in land use and other environmental factors (Hickling et
al. 2006, p. 454).
Effects from climate change in California, with its watersheds
dominated by snowmelt hydrology, are expected to have important impacts
to hydrological processes that will cascade into human and ecological
systems at many scales (Kiparsky et al. 2014, p. 1). Likely effects
include a reduction in snowpack and stream flow as well as changes in
stream flow patterns, all of which present significant challenges in a
State in which water, energy, agricultural, and ecological systems are
linked together (Barnett et al. 2008, p. 1082). These effects have
recently been summarized by hydrologic region in the California
Department of Water Resources Public Review Draft of the California
Water Plan (CWP) Update 2013 (CDWR 2013). The CWP describes future
actions that are intended to move California toward a more sustainable
management of water resources and more resilient water management
systems, and identifies objectives to support environmental stewardship
(CDWR 2013, p. ES-1). Two hydrologic regions--the Sacramento River and
the San Joaquin River--defined in the CWP encompass nearly all of our
presumed extant occurrences (Figure 2) of the valley elderberry
longhorn beetle (Fresno County not included). A summary of climate
change effects projected for these two regions is described in the
paragraphs below.
Regional temperature observations for assessing climate change are
often used as an indicator of how climate is changing, and the Western
Regional Climate Center (WRCC) has defined 11 climate regions for
evaluating various climate trends in California (Abatzoglou et al.
2009, p. 1535). These climate regions have different boundaries for
California than the CWP hydrologic regions, but are considered to be
more representative of California's diverse climatic regimes than
standard climate divisions (Pierce et al. 2013, p. 843). The relevant
WRCC climate regions for the distribution of the valley elderberry
longhorn beetle are the Sacramento-Delta and the San Joaquin Valley
regions.
Two indicators of temperature, the increase in mean temperature and
the increase in maximum temperature, are important for evaluating
trends in climate change in California. For the Sacramento-Delta
climate region, linear trends (evaluated over a 100-year time period)
indicate an increase in mean temperatures (Jan-Dec) of approximately
1.96 [deg]F (1.09 [deg]C) since 1895, and 3.0 [deg]F (1.67 [deg]C)
since 1949 (WRCC 2014a). For the San Joaquin Valley climate region, the
100-year trend in mean temperature (Jan-Dec) indicates an increase of
approximately 1.4 [deg]F (0.78 [deg]C) since 1895, and 2.62 [deg]F
(1.45 [deg]C) since 1949 (WRCC 2014c). Similarly, the maximum
temperature 100-year trend for the Sacramento-Delta region shows an
increase of about 1.42 [deg]F (0.8 [deg]C) since 1895, and 1.92 [deg]F
(1.07 [deg]C) since 1949 (WRCC 2014b). The maximum temperature 100-year
trend for the San Joaquin Valley climate region shows an increase of
about 0.38 [deg]F (0.21 [deg]C) since 1895, and 1.09 [deg]F (0.60
[deg]C) since 1949 (WRCC 2014d). It is logical to assume the rate of
temperature increase for both regions is higher for the second time
period (since 1949) than for the first time period (since 1895) due to
the increased use of fossil fuels in the 20th century.
Although these observed trends provide information relative to how
climate has changed in the past, climate science models are used to
simulate and develop future climate projections (CDWR 2013, p. SR-76).
Pierce et al. (2013, entire) presented both state-wide and regional
probabilistic estimates of temperature and precipitation changes for
California (by the 2060s) using downscaled data from 16 global
circulation models and 3 nested regional climate models. The study
looked at a historical (1985-1994) and a future (2060-2069) time period
using the IPCC Special Report on Emission Scenarios A2 (Pierce et al.
2013, p. 841), which is an IPCC-defined scenario used for the IPCC's
Third and Fourth Assessment reports, and is based on a global
population growth scenario and economic conditions that result in a
relatively high level of atmospheric GHGs by 2100 (IPCC 2000, pp. 4-5;
see Stocker et al. 2013, pp. 60-68, and Walsh et al. 2014, pp. 25-28,
for discussions and comparisons of the prior and current IPCC
approaches and outcomes). Importantly, the projections included daily
distributions and natural internal climate variability (Pierce et al.
2013, pp. 852-853).
Simulations using these downscaling methods project an increase in
yearly temperature for the Sacramento-Delta climate region ranging from
1.9 [deg]C (3.42 [deg]F) to 2.8 [deg]C (5.04 [deg]F) by the 2060s time
period (Pierce et al. 2013, p. 844), compared to 1985-1994. For the San
Joaquin Valley climate region, the simulations show an increase in
average yearly temperature ranging from 3.6 [deg]F (2.0 [deg]C) to 5.04
[deg]F (2.8 [deg]C) by the 2060s (Pierce et al. 2013, p. 844). The
simulations indicated an upper temperature increase of 4.14 [deg]F (2.3
[deg]C) from 1985-1994 to 2060-2069 (averaged across models) for both
the Sacramento-Delta and San Joaquin Valley regions (Pierce et al.
2013, p. 842).
We also reviewed projections from Cal-Adapt, a web-based, climate
adaptation planning tool that synthesizes existing downscaled climate
change scenarios and climate impact research, and presents the
predictions in an interactive, graphical layout (California Energy
Commission 2011). Projections of changes in annual averages in
temperature for the Central Valley using the Cal-Adapt Climate tool
indicate an increase in temperature ranging from about 3.4-3.8 [deg]F
(2.0-2.1 [deg]C) under the IPCC low emissions scenario (B1), to an
increase in temperature ranging from 6.0-6.6 [deg]F (3.4-3.7 [deg]C)
under the IPCC higher emissions scenario (A2) (Cal-Adapt 2014a). Both
of these scenarios represent comparisons between the baseline period
(1961-1990) and the end-of-century period (2070-2090). The
[[Page 55896]]
Cal-Adapt projection of an increase of about 2.0 [deg]C (3.4 [deg]F) in
annual average temperature is very similar to the lower end of the
range of yearly temperature simulations presented by Pierce et al.
(2013, entire) for both regions with the A2 emissions scenario.
Precipitation patterns for California are quite variable year to
year. Based on paleoclimatic data (e.g., tree-ring reconstructions of
streamflow and precipitation), hydrologic conditions in California (and
the west) are naturally widely varying, and include a pattern of
recurring and extended droughts (CDWR 2008, p. 3). However, the 100-
year trends for the Sacramento-Delta and San Joaquin Valley regions
indicate a large change in the rate of increase (or, in some cases, a
decrease) in precipitation over the winter months (December-February),
which is generally when the Central Valley receives the bulk of its
rainfall for the year. For the Sacramento-Delta region, rainfall data
from WRCC show a 100-year linear trend in winter of an increase in
precipitation of 2.26 in (5.74 cm) from 1895 to present (February
2014), but an increase of only 0.53 in (1.35 cm) from 1975 to present
(WRCC 2014e). Similar precipitation patterns are found in the San
Joaquin Valley region; that is, in winter months, there is an increase
in precipitation of 0.52 in (1.35 cm) for the 100-year trend beginning
in 1895 to present, but a 1.05 in (2.67 cm) decrease for the 100-year
trend beginning in 1975 to present (WRCC 2014f). The 100-year trends
beginning in 1975 and ending at present (February 2014) for both
regions show great variability, which is likely due, in part, to the
shorter time period being evaluated. However, observed changes in
hydrologic patterns (i.e., low-frequency changes in the hydrological
cycle such as river flow, temperature, and snowpack) over the western
United States from 1950 to 1999 have been found to be partially
attributed to the effects of climate change (Barnett et al. 2008, p.
1080).
Downscaled probabilistic climate models were also used by Pierce et
al. (2013, pp. 848-852) to evaluate changes in precipitation patterns
for California resulting from the effects of climate change. Annual
averages show different patterns in precipitation changes than those by
season; that is, model results indicate increases in winter (December-
February) precipitation for the Sacramento-Delta and San Joaquin Valley
climate regions of 5 percent and 1 percent, respectively (averaged
across all models, comparing the mean over the 1985-1994 time period to
the mean over 2060-2069) (Pierce et al. 2013, p. 849). However, these
wetter conditions in winter are largely offset by drier conditions
predicted for the remainder of the year (e.g., 4 to 20 percent decrease
in precipitation for the Sacramento-Delta region) (Pierce et al. 2013,
p. 849). Model results for the yearly change in precipitation indicate
a 3 percent decrease in precipitation for the Sacramento-Delta, and a 6
percent decrease for the San Joaquin Valley region (averaged across all
models, using mean changes over the 1985-1994 time period compared to
2060-2069) (Pierce et al. 2013, pp. 848-849).
Changing precipitation patterns and resultant changes in hydrologic
conditions are already being observed for California. In the last
century, the average early spring snowpack in the Sierra Nevada
decreased by about 10 percent, which represents a loss of 1.5 million
acre-feet of snowpack storage (CDWR 2008, p. 3). We reviewed Cal-Adapt
projections for snowpack for the western Sierra Nevada region of
California, which supplies water to many of the river systems within
the eastern portion of the Central Valley. Projected changes in April
snow water equivalence across the western Sierra Nevada region (eastern
edge of the Central Valley) indicate about an 80 percent reduction in
snow moisture under a low emissions scenario (B1); and about a 90
percent reduction in snow moisture under a high emissions scenario
(A2), between a baseline time period (1961 to 1990) and an end-of-
century period (2070 to 2090) (Cal-Adapt 2014b).
A downscaled simulation of the potential impacts of climate warming
on hydrology and water supply operations was developed expressly for
the Tuolumne and Merced River basins in California (Kiparsky et al.
2014, entire), which includes the southeastern portion of the valley
elderberry longhorn beetle's current range. Although the simulation
model (based on a Water Evaluation and Planning model) was developed
primarily to evaluate water supply concerns for urban, agricultural,
and environmental uses, the results are important as they relate to
predicted effects to streamflow and timing of hydrological events in
this portion of the Central Valley. In response to climate warming
scenarios (2 [deg]C, 4 [deg]C, and 6 [deg]C increases), the simulation
indicated a shift in timing and magnitude of seasonal flows for these
two basins; that is, earlier snowmelt and a subsequent 3-month earlier
shift in the water year for peak flows (Kiparsky et al. 2014, p. 10).
Finally, Huang et al. (2012, entire) conducted a hydrologic and
sensitivity analysis specifically for a portion of the Sacramento River
climate region, the Upper Feather River watershed, which represents
another snow-dominated watershed in California. Using six global
climate models (GCMs) with two IPCC emissions scenarios (A2 and B1),
the results of a model based on a Precipitation-Runoff Modeling System
indicate significant changes in streamflow timing and increases in both
frequency and magnitude of extreme flows (Huang et al. 2012, p. 138).
Although the authors stress the uncertainty in the model results, the
simulation found, for example, that with a 4 [deg]C (7.2[emsp14][deg]F)
warming, there was an 11 percent increase in the 100-year annual
maximum daily flow and a 35 percent decrease in the 10-year minimum 7-
day flow (i.e., drought condition) (Huang et al. 2012, p. 147). The
increase in annual peak flow was attributed to the combined effect of
more rainfall and less snowmelt with climate warming during winter
months (January-March) (Huang et al. 2012, p. 147).
As described above, the survival and reproduction of the valley
elderberry longhorn beetle, is dependent on two elderberry taxa, which
in turn are dependent upon ecological processes supported by climatic
conditions (precipitation and temperature) and other environmental
factors (e.g., elevation). Effects from climate change on the riparian
ecosystems upon which the valley elderberry longhorn beetle depends are
expected to include an increase in the intensity of both wet and dry
periods due to changes in hydrologic conditions within those California
watersheds driven by snowmelt, which is likely to alter streamflow
patterns for the riverine systems that occupy the Sacramento-Delta and
San Joaquin Valley regions (CDWR 2013, pp. SJR-73-SJR-75, SR-76-SR-78
and references cited therein). Altered flow regimes (both volume and
timing) will influence the mechanisms that support riparian plant
communities, including elderberry habitat. Shifts in location and
species composition of riparian vegetation can occur due to changes in
groundwater and surface water levels (Kl[oslash]ve et al. 2013, p. 3).
The effects of climate change are also expected to result in
increased temperatures for the Central Valley, and, when combined with
current trends and future changes in hydrologic patterns (e.g., timing
of snowmelt and peak flows), will result in an increase in the
frequency and duration of drought conditions in California. Hanson et
al. (2012, entire) presented a supply and demand modeling framework to
[[Page 55897]]
simulate and analyze potential climate change effects on conjunctive
uses of water resources within California's Central Valley from 2000-
2100. This simulation and analysis (linking downscaled GCM simulation
results, the A2 or rapidly increasing GHG emissions scenario, with
regional hydrologic models) includes the demands, uses, and movements
of water for irrigation and natural vegetation, runoff from local
mountains, and the responses of supply from groundwater and streamflow
(Hanson et al. 2012, p. 3).
Results from the simulation include intermittent climatic droughts
from 2000-2050 and sustained droughts in 2050-2100 due to reduced
precipitation (Hanson et al. 2012, p. 11). The drought events were
found to have significant effects on surface water and groundwater
deliveries and are likely to produce secondary effects, including a
reduction in water for riparian vegetation and surface water deliveries
(Hanson et al. 2012, pp. 11, 19). The simulated changes also produce
large declines in flows draining into the Central Valley from the
surrounding mountain watersheds, with a decline of over 45 percent of
potential total basin discharge by 2100 (Hanson et al. 2012, p. 11).
Reductions in streamflow diversions in this scenario are, therefore,
expected for riparian vegetation and irrigation uses, including the
Tuolumne River, the San Joaquin Basin, and Bear River in the Sacramento
Valley Tulare Basin (Hanson et al. 2012, p. 12). Additionally, the
reduction in surface water diversions increases the demand for
groundwater pumping, negatively affecting groundwater levels (Hanson et
al. 2012, p. 12) and further reducing water levels within riparian
systems, and likely causing significant land subsidence along the
southeastern San Joaquin and Sacramento Valleys (Hanson et al. 2012, p.
20).
Other predictions of riparian vegetation changes related to
climate-driven hydrological changes have found reductions in species-
rich riparian forests (boreal river system in northern Sweden)
(Str[ouml]m et al. 2012, pp. 54-56) or shifts in successional phases of
riparian vegetation (Mediterranean rivers) (Rivaes et al. 2013,
entire).
Predicted effects on both surface and groundwater availability are
likely to negatively affect the regeneration and sustainability of
riparian vegetation, including elderberry shrubs, though we are unaware
of any comprehensive evaluation of specific responses of this host
plant. The predicted changes in hydrologic conditions are also likely
to favor the spread of invasive plants.
In summary, the best available data indicate that climate change
effects will add to the destruction and modification of habitat for the
valley elderberry longhorn beetle both currently and in the future.
Although, we are unable to assess in specific quantitative terms the
magnitude of the impact due to the uncertainty relative to climate
change effects that will occur and the degree to which hydrology and
water diversions will be affected, the best available data indicate
long-term climate change effects will continue to have an overall
negative effect on the available habitat throughout the range of the
valley elderberry longhorn beetle.
Invasive Plants
Competition for resources between elderberry plants and invasive
plants and effects to elderberry habitat from invasive plants were not
included as potential threats in our 2006 5-year review (Service 2006a,
entire) or in our proposed rule, though we concluded in the proposed
rule that these threats were not well-studied and had not been
identified as widespread threats to the species or its habitat (77 FR
60250, October 2, 2012). However, the natural plant communities of the
Central Valley have been altered by removal of native trees, as
described above, and by the rapid spread of invasive plants following
the influx of immigrants and livestock into the area during the gold
rush era (Mack 1989, p. 165). As an example, the replacement of native
plants, particularly within grassland communities, by nonnative annual
grasses was nearly complete by 1880 (Mack 1989, p. 166). Based on
comments received from peer reviewers and additional information not
assessed in the proposed rule, we include here an updated and more
detailed discussion of effects to the valley elderberry longhorn beetle
from invasive plants to better assess this potential threat.
The Central Valley, as with other parts of California, continues to
experience new invasions (e.g., California Invasive Plant Council
Symposium 2003, entire). The California Invasive Plant Council (Cal-
IPC) has developed an interactive Web site (CalWeedMapper 2014) that
illustrates invasive plant distributions based on occurrence data and
suitable range modeling using climate data. CalWeedMapper was designed
as a strategic tool to identify management opportunities for control
and eradication of invasive plants. County and regional species maps
and associated reports can be created for individual invasive species
that describe their abundance, trends, and spatial distribution.
Although the information may contain errors (i.e., misidentifications
or imprecise location information), the maps provide useful information
on current distributions and trends of invasive plants in California.
Talley (2005, p. 18) observed a short-term positive effect to the
valley elderberry longhorn beetle from the invasive black locust
(Robinia pseudoacacia) (a nitrogen-fixing tree); however, this plant
has the potential to displace native plants in riparian communities
(Hunter 2000, p. 275), which can negatively affect the long-term
survival of elderberry plants (Talley 2005, p. 33). Using
CalWeedMapper, we were able to create a regional (Central Valley)
report and map for black locust (Cal-IPC 2014b). Within the presumed
extant occurrences of the valley elderberry longhorn beetle, there is a
spreading trend for this invasive plant in Butte County (Cal-IPC
2014b). This invasive plant is also considered to be ``medium'' in
abundance in parts of Sacramento County and is ``low'' in several other
areas within the northern portion of the Central Valley where the
valley elderberry longhorn beetle has been observed (Cal-IPC 2014a).
Black locust is also illustrated as ``spreading'' in several areas of
California outside of the Central Valley (Cal-IPC 2014b).
The spread of invasive plant species is expected to become more
severe in association with future changes in climate, such as drought
(e.g., Bradley et al. 2010, entire). For example, the black locust is
described as being drought tolerant, and as propagating easily from
seeds and having seeds that spread easily (Benesperi et al. 2012, p.
3556; see also Temperate Climate Permaculture 2014). In studies
elsewhere, forest plant diversity has been shown to decrease in areas
where the black locust has spread Benesperi et al. 2012, pp. 3560-
3561), and a recent experimental study concluded that its nitrogen-
fixing ability appears to give this species a competitive advantage
under drought conditions (Wurzburger and Miniat 2013, pp. 1120-1125). A
commercial horticulture Web site describes black locust as a species
that is suitable for use in times of climate change due to its
adaptability to heat and water stress (SilvaSelect 2014). As noted
above, the CalWeedMapper provides maps with general information on
current distributions and trends of invasive plants in California; the
maps do not, however, include projections of future distribution in
relation to climate change projections. Based on the available
scientific information about the black locust, we expect that its range
[[Page 55898]]
will continue to expand in response to increased temperatures and
drought projected for the range of the valley elderberry longhorn
beetle (see above for climate change projections).
Black walnut (Juglans hindsii), an invasive plant found on riparian
floodplains along the Sacramento River, is strongly associated with
elderberry and may also be invading formerly open elderberry habitat
(Vaghti et al. 2009, pp. 33-35). Black walnut is also considered a
nonnative woody plant in the Sacramento Valley, having become
established in riparian zones since its introduction into the valley in
the latter 19th and early 20th centuries as an ornamental plant or as
root stock for English walnut (Juglans regia) (Hunter et al. 2003, p.
41). As such, black walnut has been described as the most widespread
nonnative in the Sacramento Valley, based on 47 plots surveyed along 16
streams in the valley and adjacent foothills in 2003 (Hunter et al.
2003, pp. 39-46), including many areas where the valley elderberry
longhorn beetle has been observed (e.g., Feather River, American River,
Butte Creek, Big Chico Creek).
Chinese tallowtree (Triadica sebifera, formerly Sapium sebiferum)
is a deciduous tree native to east Asia that has become a major
invasive species in the southeastern United States and, since its
introduction as a shade tree in urban areas of California, has now
begun to spread in riparian areas of California (Cal-IPC 2014c). This
invasive plant has been difficult to eradicate once established (Bower
et al. 2009, p. 393). Bower et al. (2009, entire) evaluated the
invasion potential of Chinese tallowtree in California's Central
Valley. This study found that this invasive species can colonize areas
that are immediately adjacent to water sources; though drought-
intolerant seedlings appear to restrict colonization in drier (higher
elevation) areas (Bower et al. 2009, pp. 387, 393). CalWeedMapper
illustrates a spreading trend of Chinese tallowtree for areas within
Butte, Yuba, Sutter, and Sacramento Counties (Cal-IPC 2014c). Bower et
al. (2009, p. 387) reported naturalizing populations of this invasive
species along the Sacramento, San Joaquin, and American Rivers.
Hunter et al. (2003, pp. 42, 45) also described a patchy
distribution of a large number of other woody nonnative plants (i.e.,
not including black walnut) in these riparian zones, but with
relatively low abundance (less than 1 to 15 percent mean cover).
However, the study indicated that some species (e.g., tree-of-heaven
(Ailanthus altissima), Chinese tallowtree, scarlet wisteria (Sesbania
punicea), tamarisk (Tamarix sp.)) are likely expanding their ranges and
increasing in abundance in the Central Valley (Hunter et al. 2003, p.
42). In addition, this study also noted that the nonnative Himalayan
blackberry (Rubus discolor) was the typical dominant plant in the well-
developed shrub layer of the riparian zones surveyed (34 percent mean
cover, where present; observed in 70 percent of the plots surveyed)
(Hunter et al. 2003, p. 42). Finally, Golet et al. (2013, pp. 14, 17)
found that the areal extent of several nonnative, invasive plants had
increased in riparian zones along one section of the Sacramento River
(Red Bluff to Colusa) from 1999 to 2007, including an increase in black
walnut within restoration and remnant riparian sites.
Vegetation type conversion or other shifts in native plant
communities due to invasive plants represents environmental changes
that are likely to have a negative effect on the metapopulation
dynamics of the valley elderberry longhorn beetle. Although there are
reported trends of expansions of invasive and nonnative plants (e.g.,
black locust, black walnut) within the presumed extant occurrences of
the valley elderberry longhorn beetle, we are not aware of
comprehensive studies evaluating their range-wide effects on occupied
or suitable habitat of the valley elderberry longhorn beetle.
In summary, at this time, the best available scientific and
commercial information indicates potential impacts from invasive
nonnative plants (i.e., competition of resources to the host plant) to
the valley elderberry longhorn beetle and its habitat. Although
additional studies are needed to better characterize the magnitude or
impact of this threat to the species both in localized areas as well as
across the species' range, the best available data indicates that
without control of invasive nonnative plants, their spread is
anticipated to increase and will result in further degradation of
habitat and loss of host plants for the valley elderberry longhorn
beetle.
Summary of Factor A
We identified in the proposed rule and reaffirm in this document
that there has been significant loss and degradation of riparian and
other natural habitats in the presumed historical range of the valley
elderberry longhorn beetle, much of which occurred prior to the listing
of the species. Based on the best available information, occupancy
estimates of the valley elderberry longhorn beetle range between 16 and
21 percent within its historical range, within fragmented riparian
vegetation (see Background section). Our preliminary analysis of mapped
elderberry habitat presented in this document indicates that limited
areas of elderberry plant communities remain in the Central Valley and
their spatial arrangement may not support valley elderberry longhorn
beetles' presumed metapopulation structure. Restoration and mitigation
sites have contributed to available habitat, with one evaluation
indicating a long-term mitigation trend for survival of elderberry
plants of 57 to 71 percent and an occupancy rate of the valley
elderberry longhorn beetle (based on observations of exit holes only)
of 43 to 53 percent (see also discussion in Background section).
However, comprehensive surveys have not been completed at all
conservation areas, including restoration sites and preserves.
Colonization rates, where measured, are relatively low at many of these
sites. Our new assessment of habitat (occupied or unoccupied) presented
in this document, when considered in the context of the limited
occurrence records (based on our reevaluation of occurrence information
presented in the proposed rule and described in the Background section
above), confirms a rare, patchy distribution pattern of the valley
elderberry longhorn beetle across its presumed historical range in the
Central Valley.
Threats to the valley elderberry longhorn beetle's host plant due
to effects related to levee vegetation management are likely to
continue given the Corps levee vegetation management guidance and the
difficulty in obtaining a variance for this policy. A levee vegetation
strategy defined by CDWR for some facilities in the Central Valley may,
in the short term, result in fewer impacts to elderberry shrubs found
on flood control levees. However, we are uncertain if this strategy
will be effective in providing protection to elderberry shrubs found
within these areas of the Central Valley.
Impacts related to road and trail uses, and the effects of dust
from roads, trails, or highways adjacent to host plants or beetles are
not considered to be threats to the species or its habitat, but loss of
habitat at locations adjacent to roads, trails, and associated
infrastructure remains a threat. Pruning activities, if conducted
appropriately, can result in a temporary loss of the host plant of the
valley elderberry longhorn beetle and monitoring of these activities is
necessary to ensure that elderberry characteristics important to the
life history of the beetle are preserved.
[[Page 55899]]
Invasive nonnative plants may be impacting the species through
modification or loss of habitat due to competition for space and
resources with its host plant, but additional information is needed to
evaluate the magnitude of this threat.
Climate models developed for evaluating climate change effects in
California, including the Central Valley, indicate increased
temperatures and significant changes to hydrologic conditions as a
result of the effects of climate change. These changes are expected to
affect riparian systems and other habitats where the presence of the
valley elderberry longhorn beetle has been observed in the Central
Valley, and will be compounded by water supply needs for urban and
agricultural uses. Drought conditions are also likely to become more
common in California and will affect the survival of elderberry. At
this time, the best available data indicate that climate change effects
include the threatened destruction or modification of habitat through
at least the 2060s for the valley elderberry longhorn beetle.
In summary, the loss or modification of additional habitat
represents a continued threat to this population structure (see
Cumulative Effects below for additional discussion). Therefore, the
best scientific and commercial information available indicates that the
destruction, modification, or curtailment of the valley elderberry
longhorn beetle's habitat or range is likely to continue to be a threat
to the species now and in the future.
Factor B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We did not identify collecting or overutilization for any purpose
as a threat to the valley elderberry longhorn beetle in our final
listing rule (45 FR 52805; August 8, 1980) or in our proposed rule to
delist the species (77 FR 60259; October 2, 2012). Based on our review
of the available scientific and commercial information, we believe that
overutilization for commercial, recreational, scientific, or
educational purposes is not a threat to the valley elderberry longhorn
beetle at the present time nor do we anticipate this activity to be a
threat in the future.
Factor C. Disease or Predation
At the time of listing, we did not identify disease or predation as
factors affecting the status of the valley elderberry longhorn beetle
(45 FR 52805; August 8, 1980). We know of no diseases that represent
current threats to the valley elderberry longhorn beetle.
In our 5-year review and in the proposed delisting rule, we
indicated that Argentine ants may be a potential predator of the valley
elderberry longhorn beetle (Service 2006a, pp. 12-13; 77 FR 60259,
October 2, 2012). In this withdrawal, we reexamine the available
information regarding this potential predator as a threat to the
species and include information from additional studies not evaluated
in the proposed rule.
Based on sampling at sites within Putah Creek, a negative
relationship was observed between the presence of Argentine ants and
the valley elderberry longhorn beetle, which was attributed to: (1)
Native ants were found to be positively associated with the valley
elderberry longhorn beetle; and (2) native ants were found at only one
site in which Argentine ants were present (Huxel 2000, pp. 83-84).
Argentine ants were recorded at 14 of 15 mitigation sites along the
American River Parkway during surveys in 2003 and 2004 (Klasson et al.
2005, p. 8); their presence was attributed to introduction of ants with
elderberry seedlings supplied from nurseries and the use of irrigation
at these sites, the latter of which is suspected of encouraging an
increase in ant populations (Klasson et al. 2005, p. 8).
Argentine ants have rapidly expanded their range in California
since first recorded in San Bernardino County in 1905 (Vega and Rust
2001, p. 5). Within its native Argentina, Argentine ants coexist with
many ant species (Suarez et al. 1999, p. 51), including competitive
dominants such as imported red fire ants (Solenopsis invicta) and black
fire ants (S. richteri) (Holway et al. 2002, p. 195). However, in
riparian communities in California, Argentine ant colonies are known to
displace native ants (Kennedy 1998, pp. 347-348) and have the potential
to displace other native insects (see review by Holway et al. 2002,
entire). Thus, the absence of the native competitors throughout much of
the introduced range of the Argentine ant is likely an important factor
influencing its high abundance and expansion (Holway et al. 2002, p.
195). An additional concern is that climate-based modelling conducted
to examine potential changes in the global distribution of the
Argentine ant by mid-century shows that California will be one of the
areas with the most suitable conditions for this species (Roura-Pascual
et al. 2004, pp. 2531-2532), and additional modeling has yielded very
similar results (Hartley et al. 2006, pp. 1073-1077; Roura-Pascual et
al. 2011, p. 223). Although these modeling efforts cannot provide
precise locations of suitability (see Menke et al. 2009, entire), they
nevertheless provide consistent indications of the general area in
central California where climate conditions will be favorable for
Argentine ants. Also, in addition to climate, the establishment and
spread of Argentine ants is related to human-modified habitats (Roura-
Pascual et al. 2011, p. 223; Fitzgerald and Gordon 2012, pp. 534-536),
which are prevalent within the range of the valley elderberry longhorn
beetle.
In New Zealand, where the Argentine ant has been an invasive
species for more than 30 years, populations of the species disappeared
after 10-20 years (with persistence near the high end of this range
being associated with areas having warmer temperatures) at about 40
percent of 150 surveyed sites, and populations were reduced in some
other areas (Cooling et al. 2011, p. 431). The reasons for this change
are not known, and we do not know of any data indicating something
similar is occurring in California.
Argentine ants are opportunistic in their feeding behavior (Rust et
al. 2000, p. 209). Experiments in which mealworm larvae were tethered
(tied) to live elderberry stems next to traps (made from sticky tape)
conducted by Klasson et al. (2005, pp. 7-8) along the American River
Parkway area found that, when provided the opportunity, the Argentine
ant will increase its mortality (predation) of vulnerable larvae.
Specifically, the study found a significant correlation between both a
decrease of intact larvae and an increase in partially eaten larvae
with an increase in Argentine ant density (Klasson et al. 2005, p. 8).
Field experiments have shown that, when valley elderberry longhorn
beetle larvae were placed on elderberry plants, they were readily
attacked by Argentine ants (Talley 2014c, pers. comm.). Argentine ants
have also been observed interfering with adult behaviors of the valley
elderberry longhorn beetle (Talley 2014b, pers. comm.).
Relatively high densities of Argentine ants (based on the ant
traps) have been reported at mitigation sites (Klasson et al. 2005, p.
8). Elderberry plants are found in areas that are also favorable to the
establishment of Argentine ants (i.e., areas with moisture), and
Argentine ants can easily colonize natural riparian plant communities
from adjacent residential areas (Talley 2014b, pers. comm.). Argentine
ants were found on 13 percent of elderberry shrubs within 6 of 10
Central Valley watersheds surveyed in 2010 (Holyoak and Graves 2010, p.
16; Table 2). Forty-one percent of the total number of Argentine ants
observed on elderberry shrubs in these
[[Page 55900]]
six watersheds were from sites within the Putah Creek watershed
(Holyoak and Graves 2010, p. 16), similar to earlier results described
for this watershed by Huxel (2000, p. 83). Huxel et al. (2003, p. 458)
concluded that the isolation of some valley elderberry longhorn beetle
mitigation sites in conjunction with the presence of Argentine ant
colonies at some of these sites is contributing to a lower success rate
for these areas in establishing occupancy of the valley elderberry
longhorn beetle (Huxel et al. 2003, p. 458).
Successful treatment and control of Argentine ants in urban,
agricultural, and natural landscapes has been difficult (Silverman and
Brightwell 2008, pp. 234-237). Choe et al. (2014, entire) recently
described a pheromone-assisted technique that may provide an
economically viable control of Argentine ants by maximizing the
efficacy of conventional insecticide sprays; however, this technique
has not yet been evaluated as an option in natural environments. Given
the lack of safe and effective controls, it is likely that the
Argentine ant will continue to expand its range in California,
including the Central Valley.
In our 2006 5-year review and in our proposed rule, we identified
other potential predators of the valley elderberry longhorn beetle
(Service 2006a, p. 13; 77 FR 60260; October 2, 2012). This assessment
was based primarily on observations within the American River watershed
(American River Parkway), as described in an unpublished report
prepared by Klasson et al. (2005, pp. 7-8). The European earwig
(Forficula auricularia) and the western fence lizard (Sceloporus
occidentalis) were identified as potential predators of larval life
stages of the valley elderberry longhorn beetle (Klasson et al. 2005,
p. 8). The report suggested that high densities of Argentine ants and
earwigs at mitigation sites could be subsidizing higher abundances of
lizards, creating additional predation pressure on invertebrates in
these areas, though this has not been formally evaluated (Klasson et
al. 2005, p. 8). Predation of larvae by birds (woodpeckers) has been
described (Halstead and Oldham 1990, p. 25), but the small prey size
and the overall rarity of the species present a low chance of encounter
and, therefore, a low mortality risk (Talley et al. 2006a, p. 36).
However, as noted in our proposed rule, we have no empirical studies
with which to evaluate the level of predation threat from these
potential predators.
Summary of Factor C
We have no information to indicate that disease is negatively
affecting the valley elderberry longhorn beetle population. Invasive
Argentine ants have been confirmed at several locations occupied by the
valley elderberry longhorn beetle (Holyoak and Graves 2010, p. 16;
Table 2). Projections from climate change modeling indicate suitable
conditions will occur for Argentine ants to continue to spread in
California during the next several decades (Roura-Pascual et al. 2004,
pp. 2531-2532; Hartley et al. 2006, pp. 1073-1077; Roura-Pascual et al.
2011, p. 223). Studies show that Argentine ants will attack and consume
exposed insect larvae, including valley elderberry longhorn beetle
larvae. The predation threat from Argentine ants is likely to increase
in the Central Valley as colonies further expand into the species'
range unless additional methods of successful control within natural
settings become available (e.g., Choe et al. 2014, entire). Although
additional studies are needed to better characterize the level of
predation threat to the valley elderberry longhorn beetle from
Argentine ants, the best available data indicates that this invasive
species is a predation threat to the valley elderberry longhorn beetle,
and it is likely to expand to additional areas within the range of the
valley elderberry longhorn beetle in the foreseeable future.
Factor D. The Inadequacy of Existing Regulatory Mechanisms
The Act requires us to examine the inadequacy of existing
regulatory mechanisms with respect to extant threats that place the
valley elderberry longhorn beetle in danger of becoming either an
endangered or threatened species. The regulatory mechanisms affecting
the species fall into two general categories: (1) State regulatory
mechanisms; and (2) Federal regulatory mechanisms. In this withdrawal,
we incorporate additional detail and new information pertaining to
these regulatory mechanisms from what was presented in the proposed
rule. We are unaware of any local regulatory mechanisms (e.g., County
or City ordinances) that provide protections to the valley elderberry
longhorn beetle or its habitat.
State Regulatory Mechanisms
California Endangered Species Act
The California Endangered Species Act (Division 3, Chapter 1.5,
section 2050-2069 of the California Fish and Game (CFG) Code) does not
provide protections to insects and therefore would not provide
protection to the valley elderberry longhorn beetle.
The Natural Community Conservation Planning (NCCP) Act
The NCCP program is a cooperative effort between the State of
California and numerous private and public partners with the goal of
protecting habitats and species. An NCCP program identifies and
provides for the regional or area-wide protection of plants, animals,
and their habitats, while allowing compatible and appropriate economic
activity. The primary objective of the NCCP program is to conserve
natural communities at the ecosystem scale while accommodating
compatible land uses (CDFW 2014b). Regional NCCPs provide protection to
federally listed species by conserving native habitats upon which the
species depend. Many NCCPs are developed in conjunction with Habitat
Conservation Plans (HCPs) prepared pursuant to the [Endangered Species]
Act.
At present, two regional conservation plans, the San Joaquin County
Multi-Species Habitat Conservation and Open Space Plan and the Natomas
Basin HCP (revised), are located within the presumed extant occurrences
of the valley elderberry longhorn beetle, and have been permitted by
the State through the NCCP Program. Another seven regional conservation
plans within this range are currently under development. The latter
include: Butte County NCCP/HCP, Placer County NCCP/HCP, South
Sacramento HCP, Yuba-Sutter County HCP/NCCP, Yolo County HCP/NCCP,
Solano County HCP, and the Fresno County HCP. However, although Fresno
County initiated planning efforts for developing an HCP in 2007,
development of this HCP has been intermittent and it is uncertain
whether an application will be submitted to the Service (Thomas 2014,
pers. comm.). All but one of these plans (Fresno County HCP) is located
in the northern portion of the species' range in the Central Valley.
Site-specific or project-level conservation plans that have addressed
effects to the valley elderberry longhorn beetle have also been
completed within the presumed extant occurrences of the species, though
these are generally low-effect HCPs and encompass much smaller areas;
most of those are now completed (Thomas 2014, pers. comm.).
In summary, because the valley elderberry longhorn beetle is a
covered species in existing NCCPs and anticipated to be a covered
species in other NCCPs under development, the species receives
protections under the plans, including obligations to continue
[[Page 55901]]
to implement the conservation plans in their entirety under the terms
of their permits. If the valley elderberry longhorn beetle was
delisted, habitat protections and coverage under existing NCCPs would
remain unless they are amended to remove such protections. However, the
species would likely not be included as a covered species in future
NCCP/HCPs; thus, the NCCP program may not be an effective regulatory
mechanism on its own.
California Environmental Quality Act (CEQA)
CEQA (California Public Resources Code 21000-21177) is the
principal statute mandating environmental assessment of projects in
California. The purpose of CEQA is to evaluate whether a proposed
project may have an adverse effect on the environment and, if so, to
determine whether that effect can be reduced or eliminated by pursuing
an alternative course of action, or through mitigation. CEQA applies to
certain activities of State and local public agencies; a public agency
must comply with CEQA when it undertakes an activity defined under CEQA
as a ``project.'' A project is defined as an activity undertaken by a
public agency or a private activity that requires some discretionary
approval (i.e., the agency has the authority to deny or approve the
requested permit) from a government agency, and which may cause either
a direct physical change in the environment or a reasonably foreseeable
indirect change in the environment. Most proposals for physical
development in California are subject to the provisions of CEQA, as are
many governmental decisions such as adoption of a general or community
plan. Development projects that require a discretionary governmental
approval require some level of environmental review under CEQA, unless
an exemption applies (California Environmental Resources Evaluation
System (CERES) 2014). If significant effects are identified, the lead
agency has the option of requiring mitigation through changes in the
project or to decide that overriding considerations make mitigation
infeasible (Public Resources Code 21000; CEQA Guidelines at California
Code of Regulations, Title 14, Division 6, Chapter 3, sections 15000-
15387).
Take of a federally listed species, including the valley elderberry
longhorn beetle, is considered to be a ``significant effect'' under
CEQA's implementing regulations, thereby creating either a requirement
for mitigation or the identification of overriding considerations by
the CEQA lead agency. While mitigation for this class of significant
effect normally takes the form of an obligation on the part of the
project proponent to notify the Service and to take whatever action the
Service deems necessary to receive take authorization, the CEQA
obligation is an additional regulatory mechanism that frequently
provides enhanced protection when the species is listed. However, if
the valley elderberry longhorn beetle was delisted, State lead agencies
would no longer be subject to making a mandated finding of significant
effect, and therefore not otherwise be obligated to provide
conservation measures for the beetle through the CEQA process.
California Lake and Streambed Alteration Program
The Lake and Streambed Alteration (LSA) Program (CFG Code sections
1600-1616) provides protection of floodplains through its permitting
process. Section 1602 of the CFG Code requires an entity to notify the
CDFW of any proposed activity that may substantially modify a river,
stream, or lake, to include: Substantially diverting or obstructing the
natural flow of any river, stream, or lake; substantially change or use
any material from the bed, channel, or bank of, any river, stream, or
lake; or deposit or dispose of debris, waste, or other material
containing crumbled, flaked, or ground pavement where it may pass into
any river, stream, or lake. If the CDFW determines that the activity
may substantially adversely affect fish and wildlife resources, an LSA
Agreement (Agreement) is prepared. In practice, the conditions of the
LSA Agreement are negotiated with the applicant by CDFW. Although there
can be disagreement on these conditions, CDFW works with applicants to
ensure that certain wildlife protections (e.g., bird surveys during
nesting season before tree cutting) are included; arbitration is rarely
required for this process (Kennedy 2014c, pers. comm.).
We contacted CDFW staff from the agency's North Central region to
assess the level and applicability of this program to elderberry
habitat within the presumed extant occurrences in this portion of the
Central Valley. CDFW indicated that they receive up to 30 applications
per year under the LSA program for some areas within the range of the
species for activities such as construction or maintenance of bridges
and culverts, or for trail improvements (Kennedy, 2014a and 2014b,
pers. comm.; Sheya 2014, pers. comm.). Generally, the diameter of the
vegetation and amount of riparian vegetation impacted are used to
evaluate the need for an LSA agreement (Kennedy 2014b, pers. comm.).
Applicants are asked and expected to contact the Service if elderberry
shrubs will be affected (Sheya, 2014, pers. comm.; Kennedy 2014b, pers.
comm.). Should the valley elderberry longhorn beetle be delisted, there
would likely be little or no heightened concern or scrutiny under the
LSA program relative to potential impacts to its habitat (i.e.,
elderberry shrubs).
Summary of State Regulatory Mechanisms
In summary, CEQA and the LSA Program work synergistically with the
Act to provide protections to the species and its habitat. Without the
protections provided to the valley elderberry longhorn beetle under the
Act (that is, if the species was delisted), these State regulatory
mechanisms would not provide an additional level of scrutiny in the
evaluation of potential effects to the species or to its habitat from
future proposed activities. Under the NCCP Program, the valley
elderberry longhorn beetle receives protections under permitted plans,
including obligations to continue to implement the conservation plans
in their entirety under the terms of their permits. If the valley
elderberry longhorn beetle was delisted, habitat protections and
coverage under existing NCCPs would remain unless the conservation
plans were amended to remove such protections. However, the species
would likely not be included as a covered species in future NCCP/HCPs;
thus, the NCCP program may not be an effective regulatory mechanism on
its own.
Federal Regulatory Mechanisms
National Environmental Policy Act (NEPA)
All Federal agencies are required to adhere to the NEPA of 1970 (42
U.S.C. 4321 et seq.) for projects they fund, authorize, or carry out.
Prior to implementation of such projects with a Federal nexus, NEPA
requires the agency to analyze the project for potential impacts to the
human environment, including natural resources. The Council on
Environmental Quality's regulations for implementing NEPA state that
agencies shall include a discussion on the environmental impacts of the
various project alternatives (including the proposed action), any
adverse environmental effects that cannot be avoided, and any
irreversible or irretrievable commitments of resources involved (40 CFR
part 1502). The public
[[Page 55902]]
notice provisions of NEPA provide an opportunity for the Service and
other interested parties to review proposed actions and provide
recommendations to the implementing agency. NEPA does not impose
substantive environmental obligations on Federal agencies--it merely
prohibits an uninformed agency action. However, if an Environmental
Impact Statement is prepared for an agency action, the agency must take
a ``hard look'' at the consequences of this action and must consider
all potentially significant environmental impacts. The effects on
endangered and threatened species is an important element for
determining the significance of an impact of an agency action (40 CFR
1508.27). Thus, although NEPA does not itself regulate activities that
might affect the valley elderberry longhorn beetle, it does require
full evaluation and disclosure of information regarding the effects of
contemplated Federal actions on sensitive species and their habitats.
Federal agencies may also include mitigation measures in the final
Environmental Impact Statement as a result of the NEPA process that
help to conserve the valley elderberry longhorn beetle and its habitat
and these may include measures that are different than those required
through the Act's section 7 consultation process. If the valley
elderberry longhorn beetle were to be delisted, the species and its
habitat would receive no more scrutiny than other plant and wildlife
resources during the NEPA process and associated analyses of a
project's potential impacts to the human environment.
Clean Water Act
Congress passed the Federal Water Pollution Control Act Amendments
of 1972 and the CWA of 1977 to provide for the restoration and
maintenance of the chemical, physical, and biological integrity of the
nation's lakes, streams, and coastal waters. Primary authority for the
implementation and enforcement of the CWA rests with the U.S.
Environmental Protection Agency and the Corps. Section 404 of the CWA
is the principal Federal program that regulates activities affecting
the integrity of wetlands. Section 404 prohibits the discharge of
dredged or fill material in jurisdictional waters of the United States,
unless permitted by the Corps under Sec. 404(a) (individual permits),
404(e) (general permits), or unless the discharge is exempt from
regulation as designated in Sec. 404(f). The limits of jurisdictional
waters of the United States are determined by: (1) In the absence of
adjacent wetlands, jurisdiction extends to the ordinary high-water
mark; (2) when adjacent wetlands are present, jurisdiction extends
beyond the ordinary high-water mark to the limit of the adjacent
wetlands; or (3) when the water of the United States consists only of
wetlands, jurisdiction extends to the limit of the wetland. The CWA may
provide protections to elderberry because the taxon is found within
seasonal floodplain habitat. However, a site-specific jurisdictional
delineation will be required to determine whether a section 404 CWA
permit from the Corps would be required for proposed discharge of fill
material in these areas.
In addition to the measures authorized before 1972, the CWA
implements a variety of programs, including: Federal effluent
limitations and State water quality standards, permits for the
discharge of pollutants and dredged and fill materials into navigable
waters, and enforcement mechanisms. These programs may provide
additional protections of water quality within the floodplains and
riparian vegetation in which the valley elderberry longhorn beetle
occurs. Without the protections afforded by the Act, if a proposed
project area included the valley elderberry longhorn beetle or
elderberry shrubs, there would be no additional level of scrutiny of
the project's effects beyond that provided to other riparian vegetation
and floodplain resources.
Clean Air Act
With respect to regulatory mechanisms that address climate change,
there are no regulatory mechanisms in place at the national or
international levels that directly and effectively address the ongoing
or projected effects of climate change on the valley elderberry
longhorn beetle. In the United States, on December 15, 2009, the
Environmental Protection Agency (EPA) published in the Federal Register
(74 FR 66496) a rule titled: ``Endangerment and Cause or Contribute
Findings for Greenhouse Gases Under Section 202(a) of the Clean Air
Act.'' In this rule, the EPA Administrator found that the current and
projected concentrations of the six long-lived and directly emitted
GHGs--carbon dioxide, methane, nitrous oxide, hydrofluorocarbons,
perfluorocarbons, and sulfur hexafluoride--in the atmosphere threaten
the public health and welfare of current and future generations; and
that the combined emissions of these GHGs from new motor vehicles and
new motor vehicle engines contribute to the GHG pollution that
threatens public health and welfare (74 FR 66496). In effect, the EPA
has concluded that the GHGs linked to climate change are pollutants,
whose emissions can now be subject to the Clean Air Act (42 U.S.C. 7401
et seq.) (74 FR 66496; December 15, 2009). As part of its Clean Power
Plan proposal, EPA recently published proposed regulations to limit GHG
emissions for power plants (79 FR 34830, June 18, 2014), with a 120-day
comment period. However, these regulations have not been finalized.
Endangered Species Act of 1973, as Amended (Act)
Upon its listing as threatened, the valley elderberry longhorn
beetle benefited from the protections of the Act, which include the
prohibition against take and the requirement for interagency
consultation for Federal actions that may affect the species. Section 9
of the Act and Federal regulations prohibit the take of endangered and
threatened species without special exemption. The Act defines ``take''
as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or
collect, or to attempt to engage in any such conduct (16 U.S.C.
1532(19)). Our regulations define ``harm'' to include significant
habitat modification or degradation that results in death or injury to
listed species by significantly impairing essential behavioral
patterns, including breeding, feeding, or sheltering (50 CFR 17.3). Our
regulations also define ``harass'' as intentional or negligent actions
that create the likelihood of injury to a listed species by annoying it
to such an extent as to significantly disrupt normal behavior patterns,
which include, but are not limited to, breeding, feeding, or sheltering
(50 CFR 17.3). Section 7(a)(1) of the Act requires all Federal agencies
to utilize their authorities in furtherance of the purposes of the Act
by carrying out programs for the conservation of endangered species and
threatened species. Section 7(a)(2) of the Act requires Federal
agencies to ensure that any action they authorize, fund, or carry out
is not likely to jeopardize the continued existence of listed species
or destroy or adversely modify their critical habitat. As an example,
the U.S. Forest Service consults with the Service on effects of
proposed activities (e.g., vegetation management, grazing, invasive
species removal, recreational trail maintenance) to elderberry habitat
found within the Sierra National Forest; however, most of these
activities are designed so as to avoid elderberry shrubs, and are
therefore found to have no effect to the valley elderberry longhorn
beetle (Moore 2012, pers. comm.).
[[Page 55903]]
Section 6 of the Act authorizes us to enter into cooperative
conservation agreements with States and to allocate funds for
conservation programs to benefit endangered or threatened species,
which provides another potential benefit. Neither section 6 of the Act
nor Service policy gives higher priority to endangered species over
threatened species for conservation funding.
Thus, listing the valley elderberry longhorn beetle under the Act
provided a variety of protections, including the prohibition against
take and the conservation mandates of section 7 for all Federal
agencies. Because the Service has regulations that prohibit take of all
threatened wildlife species (50 CFR 17.31(a)), unless modified by a
special rule issued under section 4(d) of the Act (50 CFR 17.31(c)),
the regulatory protections of the Act are largely the same for wildlife
species listed as endangered and as threatened; thus, the protections
provided by the Act will remain in place for the duration of time that
the valley elderberry longhorn beetle remains on the Federal List of
Endangered or Threatened Wildlife.
National Wildlife Refuge System
The National Wildlife Refuge System Improvement Act of 1997 (Pub.
L. 105-57) (which amended the National Wildlife Refuge System
Administration Act of 1966 (16 U.S.C. 668dd et seq.)), expressly states
that wildlife conservation is the priority of National Wildlife Refuge
(NWR) System lands and that the Secretary shall ensure that the
biological integrity, diversity, and environmental health of refuge
lands are maintained. Each NWR is managed to fulfill the specific
purposes for which the refuge was established and the NWR System
mission; thus, the first priority of each refuge is to conserve,
manage, and, if needed, restore fish and wildlife populations and
habitats according to its purpose. This legislation requires the
development of a Comprehensive Conservation Plan (CCP) for all NWR
units (outside of Alaska). A CCP includes management actions that can
provide conservation benefits to federally listed and non-federally
listed fish and wildlife. The Sacramento River NWR, San Joaquin River
NWR, the Merced NWR, and nearly all of the lands within the San Luis
NWR are found within the presumed extant occurrences of the valley
elderberry longhorn beetle. NWR efforts to conserve the valley
elderberry longhorn beetle and its habitat are summarized in the
following paragraphs.
The Sacramento River NWR was established to conserve and manage up
to 18,000 ac (7,284 ha) of riparian or floodplain vegetation from Red
Bluff to Colusa in Tehama, Glenn, and Colusa Counties, and contains 30
different units, each with its own specific projects and management
needs (Service 2005a, p. 12). Wildlife and habitat management goals for
the Sacramento River NWR include preparing and implementing restoration
plans to restore riparian vegetation (including elderberry plants), and
maintaining existing and restored riparian vegetation (Service 2005a,
pp. 139-140; Service 2005b, p. 1, Appendix 1). The valley elderberry
longhorn beetle is the only terrestrial endemic organism found on the
Sacramento River NWR, and elderberry provides important habitat for
other taxa found there, especially other insects, migratory birds, and
the western fence lizard (Silveira 2014a, pers. comm.). Management for
the valley elderberry longhorn beetle on the Sacramento River NWR is
implemented through the management actions implemented for elderberry
habitat found throughout the refuge in riparian forests as well as with
plantings at restoration sites in mixed-riparian forest and elderberry
savanna habitats (Service 2005a, p. 118).
Occurrences of valley elderberry longhorn beetle exit holes have
been reported within the Sacramento River NWR in the CNDDB (CNDDB 2013,
entire) and from other sources (e.g., Service 2005a, p. 92). In 2004,
River Partners (2004, entire) documented the successful colonization of
the valley elderberry longhorn beetle as defined by observations of
exit holes in planted elderberries within five different units of the
refuge. At that time, the percent of elderberry shrubs with exit holes
ranged from 0.6 to 7.9 (average per refuge unit) (River Partners 2004,
pp. 2-3). Since 1993, over 100,000 elderberry plants have been planted
within 13 units of the Sacramento River NWR with an additional 14,270
plantings in another 9 units (since 1999) (Silveira 2014a and 2014b,
pers. comm.). Mean survival rates of elderberry plants range from 42
percent to 100 percent, with a combined average for all sites of about
90 percent (Silveira 2014a and 2014b, pers. comm.). The long-term
survival of elderberry at the refuge's restoration sites depends on
several factors including soil type and profile characteristics, as
well as the type of vegetation planted with elderberry; that is,
elderberry shrubs are found to be more persistent in valley oak
woodland and open savanna habitats and much less persistent in closed-
canopy mixed riparian forest (Silveira 2014a, pers. comm.).
In 2007 and 2008, Gilbart (2009, entire) surveyed 432 planted
elderberry shrubs within 8 units of the Sacramento River NWR for
occupancy (new and old exit holes) of the valley elderberry longhorn
beetle. The study found that 21 percent of all shrubs searched had new
holes, but only 33 percent of shrubs with old exit holes showed
sustained or current occupation (i.e., presence of new exit holes)
(Gilbart 2009, p. 40). Finally, although Golet et al. (2013, pp. 9, 21)
reported an increase in occupancy of the valley elderberry longhorn
beetle through colonization at restoration sites on the refuge (see
River Partners 2004, entire), they found that the ``importance value''
of elderberry, or the sum of relative density plus relative basal area,
had actually declined as restoration sites matured, suggesting that
long-term availability of suitable elderberry habitat at these sites is
uncertain.
The Sacramento River NWR has also implemented a 100-ft (30.5-m)
buffer between elderberry shrubs at its restoration sites and private
orchards, levees, or roadways to reduce the potential for colonization
on adjacent lands (Service 2005b, p. 34). This boundary was also
designed to ensure that agricultural pesticide drift from neighboring
private orchards and facility maintenance operations will not affect
valley elderberry longhorn beetle habitat within restoration sites or
adjacent landowner activities (Service 2005b, p. R-15, Appendix 2).
Monitoring and evaluation of the use of restored habitat by targeted
federally listed species, including the valley elderberry longhorn
beetle, are also established objectives for the refuge (Service 2005a,
p. 146; Service 2005b, p. 5, Appendix 1). End-of-season monitoring of
elderberry restoration sites are conducted on the Sacramento River NWR
by River Partners or The Nature Conservancy and results are provided in
annual restoration reports prepared for the refuge (Silveira 2014a and
2014b, pers. comm.).
The San Joaquin River NWR is located within the San Joaquin Valley
of the Central Valley of California and was established in 1987 to
primarily protect and manage wintering habitat for the Aleutian Canada
goose (Branta canadensis leucopareia), a former federally endangered
species (Service 2006b, p. 2). The focus of the San Joaquin River NWR
has since expanded to include other endangered or threatened species,
migratory birds, wildlife dependent on wetlands and riparian floodplain
habitat, and restoration of habitat and ecological
[[Page 55904]]
processes (Service 2006b, p. 2). The San Joaquin River NWR currently
provides habitat for both wetland- and upland-dependent wildlife
species of California's Central Valley (Service 2006b, p. 1).
Elderberry shrubs are relatively abundant on the San Joaquin River
NWR east of the San Joaquin River, but are limited west of the river
(Service 2006b, p. 171). However, there have been no comprehensive
surveys to document occupancy of the valley elderberry longhorn beetle
(Service 2006b, p. 51). The CNDDB (CNDDB 2013) includes one element
occurrence (EO 157) where exit holes were observed in surveys in May
and June of 1984; no adults were seen.
Management objectives identified in the CCP for the San Joaquin
River NWR include surveys for the valley elderberry longhorn beetle
and, if necessary, a management plan would be prepared for the species
and its habitat (Service 2006b, p. 69). However, the San Joaquin NWR
has already implemented conservation actions for the valley elderberry
longhorn beetle, including planting of elderberry shrubs on the west
side of the refuge. A large-scale (800-ac (324-ha)) restoration effort,
including several fields of elderberry plantings, was initiated on the
San Joaquin River NWR in 2002 (River Partners 2007, pp. 4, 57). In
2006, approximately 235 ac (95 ha) or 185 individual elderberry plants
(planted in 2003) were surveyed, and surveyors found that many of these
elderberry plants died as a result of prolonged flooding during the
spring and early summer of 2006 (River Partners 2007, pp. v, 4).
Subsequently, additional elderberry shrubs were planted on about 120 ac
(49 ha) at a higher elevation (77 FR 60256; October 2, 2012). As
reported in our proposed rule, much of the San Joaquin River NWR is at
an elevation such that during a wet winter and spring, flooding can
extend from 1 to 6 months over most of the refuge, which is generally
too long of an inundation time for elderberry to survive (Griggs 2007,
pers. comm.). However, the non-maintained areas of the levee system
within the refuge are also being planted with elderberry (Griggs 2007,
pers. comm.).
There are no records of exit hole observations or adult valley
elderberry longhorn beetles in either the San Luis NWR or Merced NWR
(CNDDB 2013, entire; Service 2014, GIS Analysis; Woolington 2014, pers.
comm.). Neither the San Luis NWR nor the Merced NWR has completed a
final CCP. However, a total of 1,000 elderberry plants have been
planted at both refuges, and these efforts are expected to continue in
the future (Woolington 2014, pers. comm.).
Natural Resources Conservation Service
As noted in our proposed rule, grants and loan programs implemented
through the Natural Resources Conservation Service (NRCS) and the
Service (e.g., Partners for Fish and Wildlife) can provide
opportunities for habitat enhancement of valley elderberry longhorn
beetle in the Central Valley. Under its Wetland Reserve Program (WRP)
and Emergency Watershed Protection Program (EWPP), the NRCS reported in
2011 that 1,671 ac (676 ha) in seven counties in the Central Valley
support elderberry and associated riparian plants of elderberry habitat
within either WRP perpetual easements or EWPP Flood Plain easements
(Moore 2011, pers. comm.). Although these programs are not regulatory
mechanisms because their implementation is subject to funding
availability, they are important conservation programs that benefit
both the environment and agricultural producers in the Central Valley.
The NRCS also provides financial assistance to farmers and ranchers
for planting elderberry plants, including hedgerow plantings. Since
2005, the NRCS has funded 220 hedgerow projects, creating 38 mi (61 km)
of hedgerows; an additional 100 projects encompassing 29 mi (47 km) of
hedgerows were expected to be completed by 2013 (Moore 2011, pers.
comm.). However, not all of these projects provide for planting of
elderberry. Only those hedgerow projects located in areas covered by
valley elderberry longhorn beetle Safe Harbor Agreements (San Joaquin
and Yolo Counties) are consistently planted with elderberry shrubs
(Moore 2011, pers. comm.). We have no information on the occupancy of
the valley elderberry longhorn beetle within WRP perpetual or EWPP
Flood Plain easements or hedgerow plantings.
Sikes Act and Other Department of Defense Programs
The Sikes Act (16 U.S.C. 670a-670f, as amended) directs the
Secretary of Defense, in cooperation with the Service and State fish
and wildlife agencies, to carry out a program for the conservation and
rehabilitation of natural resources on military installations. The
Sikes Act Improvement Act of 1997 (Pub. L. 105-85) broadened the scope
of military natural resources programs, integrated natural resources
programs with operations and training, embraced the tenets of
conservation biology, invited public review, strengthened funding for
conservation activities on military lands, and required the development
and implementation of an Integrated Natural Resources Management Plan
(INRMP) for relevant installations, which are reviewed every 5 years.
INRMPs incorporate, to the maximum extent practicable, ecosystem
management principles, provide for the management of natural resources
(including fish, wildlife, and plants), allow multipurpose uses of
resources, and provide public access necessary and appropriate for
those uses without a net loss in the capability of an installation to
support its military mission. Although INRMP implementation is
technically not a regulatory mechanism because its implementation is
subject to funding availability, it is an important guidance document
that helps to integrate natural resource protection with military
readiness and training. In addition to technical assistance that the
Service provides to the military, the Service can enter into
interagency agreements with installations to help implement an INRMP.
These INRMP implementation projects can include wildlife and habitat
assessments and surveys, fish stocking, exotic species control, and
hunting and fishing program management.
Beale Air Force Base (Beale AFB) is located in Yuba County, in the
northeastern part of the Sacramento Valley, approximately 13 mi (21 km)
east of Marysville and 40 mi (64 km) north of Sacramento. Beale AFB is
located within an ecological and geographic transition zone between the
flat agricultural lands of the Sacramento Valley to the west and the
foothills of the western slope of the Sierra Nevada to the east; three
tributaries to the Bear River (Reeds, Hutchinson, and Dry Creeks) run
through the base (DOD 2011, p. 33). Several areas of elderberry shrubs
are found on Beale AFB, including shrubs planted within conservation
areas for compensation and habitat restoration purposes (Capra 2011,
pers. comm.).
In 2011, an updated INRMP was prepared, which underwent an annual
review in 2013 by the installation in coordination with the Service and
CDFW (DOD 2011, entire). The Beale AFB INRMP Work Plan includes goals
and objectives to maintain or increase populations of special status
species and improve their habitat conditions (DOD 2011, p. 164).
Specifically, the Work Plan includes monitoring of the valley
elderberry longhorn beetle in compliance with a Special Area Management
Plan (SAMP) Habitat Restoration, Monitoring and Management Program
(HRMMP) (DOD
[[Page 55905]]
2011, p. 165). The SAMP establishes a framework for habitat
conservation, compensation, and watershed management and designates
areas on the base that are, or will be, protected and preserved (DOD
2011, p. 23). A programmatic biological opinion was developed with the
Service to establish a predictable process for federally listed species
consultation and compensation on the base, and one in which future
routine consultations would be shortened (DOD 2011, p. 27). In October
2012, the Service completed a formal consultation for effects to the
valley elderberry longhorn beetle related to activities implemented
under the SAMP (Service 2012, entire). The monitoring program
established within the SAMP HRMMP includes sampling a random selection
of 25 percent of mapped elderberry shrubs every 2 years and a notation
of the physical condition of the monitored shrubs and the presence or
absence of exit holes (DOD 2011, page A9-24).
As described in the INRMP, approximately 697 elderberry shrub
locations were identified as occurring on Beale AFB, and the largest
shrubs were surveyed in 2005 to determine the potential presence of
valley elderberry longhorn beetle on base (DOD 2011, A2-29). Exit holes
were found in 25 percent (13 of 51) of shrubs sampled in a riparian
preservation area, but no adult beetles were observed (DOD 2011, pp.
A2-29--A2-30). Exit holes were also found in 2012 in elderberry habitat
at another location on the base (DOD 2014). Since fiscal year 1996, the
base has received $73,000 to $400,000 per year for Habitat Conservation
Management Plan (HCMP) implementation and monitoring (DOD 2011, p. A2-
44). Based on this funding history, it is likely that HCMP projects
will continue to be implemented in the future as funds are approved,
and the INRMP/HCMP continues to provide a conservation benefit to the
valley elderberry longhorn beetle (DOD 2011, p. A2-44). Without the
protections provided to the species and its habitat under the Act (that
is, if the valley elderberry longhorn beetle was delisted), there would
be no regulatory incentive for the INRMP and HCMP to continue to
include important provisions (e.g., monitoring) that provide
conservation benefits to the species, beyond that provided under a
larger integrated natural resource management strategy at Beale AFB.
Summary of Factor D
State regulatory mechanisms provide a limited amount of protection
against current threats to valley elderberry longhorn beetle. The
requirements of CEQA and the LSA program may provide limited
protections for the valley elderberry longhorn beetle and its host
plant. However, without the protections provided to the valley
elderberry longhorn beetle under the Act (that is, if the species was
delisted), these State regulatory mechanisms would not provide an
additional level of conservation benefit to the species or to its
habitat. The NCCP program can provide important protections through
implementation of management actions and conservation measures when the
valley elderberry longhorn beetle and its host plant are incorporated
in regional or project-level conservation plans, including obligations
to continue to implement the conservation plans in their entirety under
the terms of their permits. If the valley elderberry longhorn beetle
was delisted, habitat protections and coverage under existing NCCPs
would remain unless the conservation plans were amended to remove such
protections. However, the species would likely not be included as a
covered species in future NCCP/HCPs; thus, the NCCP program may not be
an effective regulatory mechanism on its own.
A variety of Federal regulatory mechanisms exist throughout the
range of the valley elderberry longhorn beetle. NEPA does not itself
regulate activities that might affect the valley elderberry longhorn
beetle, but it does require full evaluation and disclosure of
information regarding the effects of contemplated Federal actions on
sensitive species and their habitats. The CWA may provide protections
to elderberry because the taxon is found within seasonal floodplain
habitat. However, a site-specific jurisdictional delineation will be
required to determine whether a section 404 CWA permit from the Corps
would be required for actions proposed for these areas. While the Clean
Air Act gives the EPA authority to limit GHGs linked to climate change,
the regulations that the EPA has proposed regarding GHG emissions from
power plants have yet to be finalized and thus cannot be considered
existing regulatory mechanisms. At this time, we are not aware of any
regulatory mechanisms in place at the international or national levels
that address the ongoing or projected effects of climate change on the
valley elderberry longhorn beetle.
We expect management actions currently being implemented and,
depending on funding, planned for the future for the Sacramento River
NWR and San Joaquin River NWR will continue to provide important
conservation benefits to the valley elderberry longhorn beetle,
although occupancy (based on exit holes) for these locations has been
very low. In addition, comprehensive surveys for adults or exit holes
have not been conducted on refuge lands or at easements established
under NRCS programs. The Department of Defense also provides some
protections to valley elderberry longhorn beetle and its habitat in the
Central Valley at Beale AFB through implementation of its INRMP under
the Sikes Act.
Overall, although regulatory mechanisms are in place and provide
some protection to the valley elderberry longhorn beetle and its
habitat, absent the protections of the Act (e.g., section 7 and section
10(a)(1)(B)), these mechanisms would not provide adequate protection
from the threats currently acting on the species.
Factor E. Other Natural or Manmade Factors Affecting Its Continued
Existence
Natural and manmade factors affecting the valley elderberry
longhorn beetle evaluated in this section include some effects related
to climate change (related to temperature changes) and pesticides that
may impact the survivorship or reproductive success of the species. See
additional discussion on potential effects of climate change above
under Factor A. In the proposed rule, we presented a general discussion
of pesticide use in the Central Valley, but stated that we did not have
information that confirmed pesticide use was a significant threat to
the valley elderberry longhorn beetle (77 FR 60262-60263; October 2,
2012). In this withdrawal, we present more recent information regarding
pesticide usage trends in the Central Valley and include a detailed
discussion of effects of one class of pesticides to insects relative to
their potential effects to the valley elderberry longhorn beetle.
Additionally, we provide an updated summary discussion of small
population size as a potential threat, as was discussed in the proposed
rule (77 FR 60263; October 2, 2012).
In this revised Factor E analysis, we do not include a discussion
of loss of populations resulting from habitat fragmentation as
described in the proposed rule (77 FR 60264; October 2, 2012). We
indicated in the proposed rule that we were not aware of any
information that would support robust conclusions regarding the extent
of isolation of valley elderberry longhorn beetle populations at
distances greater than a presumed recolonization distance of 25 mi (40
km) (77 FR 60264; October
[[Page 55906]]
2, 2012). At present, we have no population trends for the valley
elderberry longhorn beetle to draw conclusions regarding loss of
specific populations within the range of the species, and we are
unaware of any viable tools to evaluate potential fragmentation of
elderberry habitat in order for us to evaluate this potential threat.
Temperature and Other Effects of Climate Change
As described above (see Factor A), increased temperatures are
projected for the current range of the valley elderberry longhorn
beetle. At this time we do not know what temperature levels (in terms
of either isolated heat spikes or extended periods of high heat) are
lethal for the species, or whether and how such changes may affect
survivorship or reproductive success. We also do not have information
to assess the near- or long-term adaptive capacity of this species in
relation to climate change effects. Specifically in the near term we do
not have information about its ability to make behavioral or
physiological changes that will allow individuals to persist as
temperatures increase within its current range. In this regard, we also
are concerned by the relatively limited dispersal ability of the
species, which could limit its ability to undertake range shifts in
response to changing climate conditions. The range shifts in latitude
and elevation reported for some other species of longhorn beetles in
Great Britain (Hickling et al. 2006, pp. 451-453) are of interest, but
we do not know whether this is applicable to the valley elderberry
longhorn beetle and the habitat fragmentation and other conditions it
faces. Also, at this time we have no information on the possibility of
genetic (evolutionary) adaptation that could influence population- and
species-level persistence over generations in the face of changing
temperatures or other physical effects of a changing climate.
Pesticides
In our 2006 5-year review and our 2012 proposed rule, we evaluated
pesticide use in the Central Valley as a potential threat to the valley
elderberry longhorn beetle (Service 2006a, pp. 18-19; 77 FR 60262;
October 2, 2012). As noted in our proposed rule, there have been
reports of potential effects to elderberry shrubs (yellowing of leaves)
adjacent to cultivated fields recently treated by aerial crop dusting
(Barr 1991, p. 27). We concluded in our proposed rule that we lacked
information confirming that pesticide use was a significant threat to
the valley elderberry longhorn beetle (77 FR 60263; October 2, 2012).
In this withdrawal, we provide an updated and more detailed discussion
of this potential threat based on peer reviewer comments and species'
experts (e.g., Talley et al. (2006b, p. 44)) conclusions that pesticide
impacts to the species and its habitat are likely given the level of
pesticide use (both urban and agricultural uses) in parts of the
Central Valley and the proximity of agriculture to riparian vegetation.
Pesticide use in California varies from year to year and is
dependent on a number of factors, with weather conditions being
particularly important (California Department of Pesticide Regulation
(CDPR) 2014, p. 70). Short time periods (3 to 5 years) can suggest
either an upward or downward trend in pesticide use; however,
regression analyses of usage from 1998 to 2012 have not revealed a
significant trend in either direction (CDPR 2014, p. 17). Pesticide use
(pounds of active ingredient) in the lower portion of the San Joaquin
Valley) are among the highest in the State (based on county reports)
(CDPR 2014, pp. 12-13), though with the exception of San Joaquin
County, much of this portion of the Central Valley is considered to be
outside the area defined by the presumed extant occurrences of the
valley elderberry longhorn beetle. However, in the northern portion of
the range of the valley elderberry longhorn beetle (Tehama County south
to Sacramento County), pesticide use ranks relatively high (in the top
20) for several counties (CDPR 2014, pp. 12-13). Based on the amount
applied, the most-used pesticide types are combination fungicide/
insecticides (mostly sulfur), fumigants, and insecticides (CDPR 2014,
p. 66). Based on cumulative area treated, the most-used types are
insecticides, herbicides, and fungicides (CDPR 2014, p. 66).
Neonicotinoid insecticides such as imidacloprid are used
extensively for some crops in California (e.g., wine grapes; CDPR 2014,
p. 76). They are also widely used as seed treatments (Goulson 2013, p.
978). The use of imidacloprid on agricultural land in the Central
Valley of California was estimated at over 0.24 pounds per square mile
in 2011 (USGS 2014); CDPR reported a total of 297,384 pounds of
imidacloprid were applied in California in 2012, encompassing 64,209
agricultural applications (CDPR 2014, pp. 413-416).
Neonicotinoids are particularly toxic to insects in small
quantities (Goulson 2013, p. 977). Experimental studies have also found
important sublethal effects to Asian longhorned beetles in response to
imidacloprid, including a reduction in the number of viable eggs (Ugine
et al. 2011, p. 1948) and a decrease in food consumption (Russell et
al. 2010, p. 308). A lack of sufficient locomotor control is suspected
as the cause of some of the changed behaviors, rather than the
palatability of food (Ugine et al. 2011, p. 1,948). Concerns regarding
the environmental risks of neonicotinoid insecticides to honeybees have
prompted recent efforts to provide additional control of their usage
(e.g., application restrictions; EPA 2013, entire).
Studies of exposure to neonicotinoids have also shown differential
effects to the behaviors and community dynamics of ants (Barbieri et
al. 2013, entire). Interspecific aggressive behavior and colony fitness
differences after exposure to imidacloprid were observed for the
invasive Argentine ant and a native ant (Monomorium antarcticum)
(Barbieri et al. 2013, p. 5). The study results suggest that in areas
in which a native ant species has been previously exposed to
neonicotinoid insecticides, the Argentine ant could have an advantage
in securing food resources and overall survival (Barbieri et al. 2013,
p. 5). Altered behaviors in ant populations due to pesticide exposure
may be an important contributing factor to the predation threat of
Argentine ants for those areas where occupancy of the valley elderberry
longhorn beetle has been shown to co-occur with this invasive ant.
However, these effects have not been formally evaluated.
The timing of pesticide applications are also likely to coincide
with vulnerable life stages (adult activity, exposure of eggs and
larvae) of the valley elderberry longhorn beetle (Talley et al. 2006b,
p. 43). However, we are unaware of any specific studies of either
exposure, or responses to exposure, to pesticides for the valley
elderberry longhorn beetle.
We evaluated information that indicates pesticides are likely
present in areas around and adjacent to valley elderberry longhorn
beetle habitat, including areas occupied by the species, which creates
the potential for exposure of the beetle and its habitat to harmful
pesticides through unintended drift from applications, as well as
potential secondary effects to insect communities in riparian
vegetation that may create an advantage for potential predators (i.e.,
Argentine ants) of the valley elderberry longhorn beetle. Based on our
evaluation presented in the proposed rule and updated information
presented above, the best available scientific and
[[Page 55907]]
commercial information indicates potential impacts from pesticides to
the valley elderberry longhorn beetle and its habitat; however, further
studies are needed to characterize the magnitude or impact of
pesticides to the species both in localized areas as well as across the
species' range.
Small Population Size
In our proposed rule, we concluded that the best available
information did not indicate small population size was a significant
concern at that time or in the future (77 FR 60263; October 2, 2012).
We provide in this withdrawal a reiteration of this potential threat
without making inferences based on incomplete data regarding population
size, locations of populations, and population trends.
Although we do not have data from which to draw conclusions
regarding the population size of the valley elderberry longhorn beetle,
we nonetheless consider whether rarity might pose a potential threat to
the species. While small populations are generally at greater risk of
extirpation from normal population fluctuations due to predation,
disease, changing food supply, and stochastic (random) events such as
fire, corroborating information regarding threats beyond rarity is
needed to meet the information threshold indicating that the species
may warrant listing. In the absence of information identifying threats
to the species and linking those threats to the rarity of the species,
the Service does not consider rarity alone to be a threat. Further, a
species that has always had small population sizes or has always been
rare, yet continues to survive (as is the case for the valley
elderberry longhorn beetle; see Background section) could be well-
equipped to continue to exist into the future.
Many naturally rare species have persisted for long periods within
small geographic areas, and many naturally rare species exhibit traits
that allow them to persist despite their small population sizes.
Consequently, the fact that a species is rare or has small populations
does not necessarily indicate that it may be in danger of extinction
now or in the future. We need to consider specific potential threats
that might be exacerbated by rarity or small population size. Although
low genetic variability and reduced fitness from inbreeding could
occur, at this time we have no evidence of genetic problems with the
valley elderberry longhorn beetle. The valley elderberry longhorn
beetle is known to be endemic to the Central Valley since at least 1921
(Fisher 1921, p. 207), and has historically survived fires, drought,
and other stochastic events. We have no data to indicate that rarity or
small population size, in and of themselves, pose a threat to the
species at this time or in the future.
Summary of Factor E
Based on the best scientific information available, we do not know
whether increased temperature and other projected effects associated
with a changing climate in the coming decades (per projections for the
2060s) will exceed lethal levels or influence the survivorship and
reproductive success of the valley elderberry longhorn beetle. We also
do not know what adaptive capacity the species has, which will
influence its response to increased temperature and other physical
changes in climate.
The best available scientific information indicates potential
impacts from pesticides to the valley elderberry longhorn beetle and
its habitat; however, further studies are needed to characterize the
magnitude or impact of pesticides to the species both in localized
areas as well as across the species' range. Pesticide use in the
Central Valley remains high and could increase due to climate change
effects (e.g., warmer temperatures) that may enhance the pathogenicity
of crop pests for agricultural fields that are commonly found adjacent
to remnant riparian vegetation.
We do not believe that small population size constitutes a threat
to the valley elderberry beetle throughout all or a significant portion
of its range currently or in the future.
Cumulative Effects
Threats can work in concert with one another to cumulatively create
conditions that will impact the valley elderberry longhorn beetle
beyond the scope of each individual threat. Some of the threats
discussed in the proposed rule and reevaluated in this document are
expected to work in concert with one another to cumulatively create
situations that are likely currently impacting and likely will impact
the valley elderberry longhorn beetle or its habitat beyond the scope
of the individual threats that we have already analyzed.
For some species, vulnerabilities to climate change effects have
been found to be dependent on interactions between life-history traits
and spatial characteristics (Pearson et al. 2014, p. 218), and it is
likely that this is also true for other taxa, including the valley
elderberry longhorn beetle. Climate change effects (e.g., warmer
temperatures, increase in drought events, and changes in precipitation
patterns) are likely to increase the extinction risk of the valley
elderberry longhorn beetle and can also affect its host plant, e.g., by
creating conditions that favor the expansion of invasive species in the
Central Valley, or by outright reduction in host plants if the effects
of climate change are more than elderberries can tolerate. An increase
in temperature expected before the end of this century will also take
place in concert with changes in land use and other environmental
factors such as pesticide use, altered habitat due to invasive plant
species, predation threats, and secondary effects of climate change
(altered hydrologic conditions). Although distributional shifts of the
valley elderberry longhorn beetle (e.g., in both elevation and
latitude) might be observed in the future given the alteration of
climate, especially with increases in temperature, the limited
remaining fragmented habitat and relatively limited dispersal ability
of the species may restrict any such range shift. Data from long-term
population trends of the beetle and its habitat will be needed to
evaluate these types of potential cumulative effects.
Determination
As required by the Act, we considered the five factors in assessing
whether the valley elderberry longhorn beetle meets the definition of
an endangered or threatened species. We examined the best scientific
and commercial information available regarding the past, present, and
foreseeable future threats faced by the species. Based on our review of
the best available scientific and commercial information, we find that
the current and future threats are of sufficient imminence, intensity,
or magnitude to indicate that the valley elderberry longhorn beetle
remains likely to become endangered within the foreseeable future
throughout all of its range. Therefore, the valley elderberry longhorn
beetle currently meets the definition of a threatened species, and we
are withdrawing the proposed rule to delist the valley elderberry
longhorn beetle. Our rationale for this finding is outlined below.
We presented valley elderberry longhorn beetle occurrence (adult
beetle and exit hole data) and distribution information in the proposed
rule (77 FR 60238; October 2, 2012) that we determined to be the best
available scientific and commercial information at that time. However,
based on the peer review and public comments received on the proposed
rule, including new information received, we reevaluated
[[Page 55908]]
the beetle's biological information and the five-factor analysis
prepared for the proposed rule to determine where clarifications,
corrections, or revisions were necessary. In this rule, we provide a
revised description of the location of observations of adult valley
elderberry longhorn beetles or exit holes and present an updated
distribution map based on surveys conducted since 1997. Our reanalysis
of survey reports and published studies (including a reexamination of
the best available data) helped us assess the relative quality of the
species' occurrence (e.g., CNDDB records), location, and occupancy data
presented in the proposed rule. As noted above (see Background
section), the population structure for the valley elderberry longhorn
beetle has been characterized as patchy-dynamic; that is, one
controlled by both broad-scale factors associated with elderberry
shrubs (e.g., shrub age) and riparian-associated environmental
variables, which have patch, gradient, and hierarchical features (e.g.,
relative elevation) (Talley 2007, p. 1486). The valley elderberry
longhorn beetle remains localized in its distribution, with limited
dispersal ability, and we estimate it occupies less than 25 percent of
the remaining elderberry habitat found within fragmented riparian
areas.
Our reanalysis of information in our files and new information
received during the open comment periods changed our evaluation of the
threats to the species. In this withdrawal we conclude that the valley
elderberry longhorn beetle continues to be threatened by habitat loss
or degradation (Factor A) and predation (Factor C) throughout all of
its range. Additional environmental factors (e.g., additional habitat
loss) and other stressors (e.g., effects related to pesticide use,
competition to its host plant from invasive species) are likely to
influence the species' distribution and likelihood of extinction in the
foreseeable future.
Despite the fact that we are not delisting the valley elderberry
longhorn beetle, our reanalysis of information in our files and new
information received has helped us better define our management actions
directed at conserving the species, such as: (1) Improve our survey
techniques to better define its distribution and abundance; (2)
implement data management practices to better evaluate conservation
measures being implemented at mitigation and restoration sites; (3)
refine our evaluation of potential threats to the species (e.g., those
related to climate change effects); (4) continue to promote restoration
of riparian habitat; and (5) work with our partners to identify and
implement key research needs to improve our understanding of the
species.
The valley elderberry longhorn beetle remains likely to become an
endangered species in the foreseeable future because it is a habitat
specialist, with limited dispersal ability and a short adult life span,
and it possesses rarity traits such as low local numbers within a
population structure that has become fragmented within its historical
range, and continues to be fragmented further by ongoing impacts to its
habitat.
Although evidence of occupancy (primarily observations of exit
holes) for the species has been documented in additional locations than
those recorded at the time of listing in 1980 (as discussed in the
proposed rule), we believe this is the result of limited data available
at the time of listing, combined with subsequent surveys that have
better defined the presumed historical range of the valley elderberry
longhorn beetle. Following our reexamination of the original surveyor
data sets (as described in the Population Distribution section above),
new occurrence information received (i.e., Arnold 2014a, pers. comm.,
2014; DOD 2014; River Partners 2011), an examination of the quality of
valley elderberry longhorn beetle records contained in the CNDDB, and
an evaluation of occupancy estimates based on several surveys (Collinge
et al. 2001, p. 111; Talley et al. 2007, pp. 25-26; Gilbart 2009, p.
40; Holyoak and Graves, 2010, entire; Holyoak and Graves 2010, Appendix
1), we conclude there are extant occurrences of the valley elderberry
longhorn beetle at 36 geographical locations in the Central Valley.
However, these locations are based in large part on observations of
exit holes, which may not be an accurate depiction of occupancy (see
Life History discussion in Background section). When considering data
of adult male occurrences (which may be a more accurate depiction of
occupancy), only 25 percent (9 of the 36 locations) of these records,
within 4 hydrologic units, represent observations of adult male beetles
recorded since 1997. In making our determination, we also assessed the
amount and spatial arrangement of mapped elderberry habitat within the
Central Valley. However, we acknowledge that there are no current
estimates of population size or trends in population numbers for the
valley elderberry longhorn beetle.
Restoration and mitigation efforts have provided elderberry habitat
for the valley elderberry longhorn beetle, but very little
comprehensive monitoring has been conducted to evaluate the success of
these sites, both in terms of habitat of value to the species and
occupancy of these habitats. Comprehensive monitoring at restoration
and mitigation sites as well as natural sites remaining in the Central
Valley is needed in order to produce definitive population trends of
occupancy for this species. A second year of trial surveys for the
valley elderberry longhorn beetle using pheromone attractants is
currently under way (Sanchez 2014, pers. comm.) to further evaluate
this method to assess the status of this species within its presumed
range. This survey technique could also provide valuable information on
populations of both elderberry longhorn beetles (Desmocerus
californicus dimorphus, D. californicus californicus).
As described in our Factor D analysis, conservation plans and
programs are currently in place or planned for some portions of the
valley elderberry longhorn beetle's range. State regulatory mechanisms,
such as CEQA and the LSA, may provide limited protections for the
species' host plant as they work synergistically with the Act to
provide protections to the species and its habitat.
Although Federal regulatory mechanisms other than the Act can offer
protection to the valley elderberry longhorn beetle in small areas of
the species' range, we believe that the Act represents the primary
regulatory mechanism for conservation of the valley elderberry longhorn
beetle. If the valley elderberry longhorn beetle were to be delisted,
it would not receive the substantial protections provided to the
species and its habitat under the Act.
Based on our review of the best available scientific and commercial
data, we conclude that the valley elderberry longhorn beetle currently
meets the definition of a threatened species because current and future
threats including present and continued loss or modification of its
habitat, predation, and threats related to the effects of climate
change are of sufficient imminence, intensity, or magnitude to indicate
that the valley elderberry longhorn beetle is likely to become
endangered within the foreseeable future throughout all or a
significant portion of its range.
Significant Portion of the Range
In determining whether a species is endangered or threatened in a
significant portion of its range, we first identify any portions of the
range of the species that warrant further consideration. The range of a
species can theoretically be divided into
[[Page 55909]]
portions an infinite number of ways. However, there is no purpose to
analyzing portions of the range that are not reasonably likely to be
both: (1) Significant, and (2) endangered or threatened. To identify
only those portions that warrant further consideration, we determine
whether there is substantial information indicating that: (1) The
portions may be significant, and (2) the species may be in danger of
extinction there or likely to become so within the foreseeable future.
In practice, a key part of this analysis is whether the threats are
geographically concentrated in some way. If the threats to the species
are essentially uniform throughout its range, no portion is likely to
warrant further consideration. Moreover, if any concentration of
threats applies only to portions of the species' range that are not
significant, such portions will not warrant further consideration.
If we identify portions that warrant further consideration, we then
determine whether the species is endangered or threatened in these
portions of its range. Depending on the biology of the species, its
range, and the threats it faces, the Service may address either the
significance question or the status question first. Thus, if the
Service considers significance first and determines that a portion of
the range is not significant, the Service need not determine whether
the species is endangered or threatened there. Likewise, if the Service
considers status first and determines that the species is not
endangered or threatened in a portion of its range, the Service need
not determine if that portion is significant. However, if the Service
determines that both a portion of the range of a species is significant
and the species is endangered or threatened there, the Service will
specify that portion of the range as endangered or threatened under
section 4(c)(1) of the Act.
The primary threats to the valley elderberry longhorn beetle occur
throughout the species' range and are not restricted to, or
concentrated in, any particular portion of that range. The primary
threats of loss or modification of habitat, invasive plants, predation,
and pesticides are impacting valley elderberry longhorn beetle
populations throughout the species' range. The effects of climate
change are also acting on the valley elderberry longhorn beetle
throughout its range. Thus, we conclude that threats impacting the
valley elderberry longhorn beetle are not concentrated in certain
areas, and, thus, there are no significant portions of its range where
the species should be classified as an endangered species. Accordingly,
this withdrawal and our determination that the valley elderberry
longhorn beetle remains listed as a threatened species applies
throughout the species' entire range.
Summary of Comments and Recommendations
In the proposed rule published on October 2, 2012 (77 FR 60238), we
requested that all interested parties submit written comments on the
proposal by December 3, 2012. We also contacted appropriate Federal and
State agencies, scientific experts and organizations, and other
interested parties and invited them to comment on the proposal. A
newspaper notice inviting general public comment was published in the
Sacramento Bee on October 12, 2012. We did not receive any requests for
a public hearing. We reopened the comment period on January 23, 2013
(78 FR 4812) to allow all interested parties an additional opportunity
to comment on the proposed rule and to submit information on the status
of the species. The final comment period closed February 22, 2013.
During the two comment periods for the proposed rule, we received
comments from 35 different entities or individuals (not including peer
review comments) addressing the proposed delisting of the valley
elderberry longhorn beetle. Submitted comments were both supportive of
and against delisting the species. All substantive information provided
during the comment periods has either been incorporated directly into
this withdrawal or addressed below.
Peer Review
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270) and the Office of Management and Budget's December 16,
2004, Final Information Quality Bulletin for Peer Review, we solicited
expert opinion from four appropriate and independent specialists with
scientific expertise of the life history and biology of the valley
elderberry longhorn beetle and riparian systems in the Central valley
of California. The peer review process was facilitated by Atkins, North
America, and a final report of the peer review, including all comments,
was prepared in January 2013 (Atkins 2013, entire), and made available
on the Internet at http://www.regulations.gov at Docket No. FWS-R8-ES-
2011-0063.
We used the 10 questions posed to the peer reviewers as described
in the final peer review report (Atkins 2013, entire) to organize and
summarize the comments received from the four peer reviewers, including
substantive issues and new information relevant to the valley
elderberry longhorn beetle. The peer review comments are summarized and
addressed in the following section based on 10 questions posed to the
peer reviewers by the Service. Relevant information contained in both
the summary of the peer reviewer comments and by individual peer
reviewers has been incorporated into this rule, where appropriate.
Peer Review Comments
(1) Comment: All four peer reviewers identified instances in which
the descriptions, analyses, and biological findings and conclusions
presented in the proposed rule are not supported by the available data,
and stated that further explanation is needed on the limitations of the
data, assumptions, and rationale for dismissing certain topics. Two
peer reviewers questioned the conclusions in the proposed rule
regarding the range of the valley elderberry longhorn beetle, and all
reviewers noted that the CNDDB records used to define the locations of
extant locations of the species are outdated, may not be accurate, or
may be misidentified for the non-listed California elderberry longhorn
beetle. For example, two peer reviewers questioned the validity of the
CNDDB use of exit holes in elderberry stems as a measure of the
presence of the valley elderberry longhorn beetle. Three peer reviewers
also commented on the lack of population size and trend estimates and
the lack of available data for newer mitigation and restoration sites.
Our Response: For this rule, we reevaluated the quality and
addressed the limitations of the available species occurrence
information. We then developed a revised description of the location of
observations of adult valley elderberry longhorn beetles or exit holes,
and prepared new distribution maps based on surveys conducted since
1997 (16 years). We believe this time period represents a conservative,
but reasonable period for evaluating available occurrence information
as this was the year in which the most recent, comprehensive rangewide
survey was conducted by observers known to be qualified to detect
occupancy of the species. We included a more detailed description of
our analyses including how we reevaluated the available occurrence
information, including those locations that may represent observations
of the other subspecies found in California (see Population
Distribution, Presumed Historical Range, and Current Distribution
(since 1997) sections), thus addressing the peer
[[Page 55910]]
reviewers concerns related to outdated, inaccurate, or misidentified
CNDDB records. We also included available summaries of observations
from both mitigation and restoration sites, and acknowledged the
limitations with these and other data sets (e.g., see Restoration and
Mitigation Sites section).
(2) Comment: All four peer reviewers stated that different
conclusions than those presented in the proposed rule could be drawn
due to limitations of available data (data gaps), and our over-
simplification and over-estimation of the available data. Specifically,
one peer reviewer stated that we overlooked important and well-
documented uncertainties in the available data, while another stated
that there may be fewer than the 26 locations identified in the
proposed rule, which would affect our conclusions concerning the
effects of threats. Another peer reviewer stated that many of the 26
locations should be disregarded given the lack of current information
and that our characterization of habitat at some of these locations was
questionable.
Our Response: To address all of these concerns (e.g., the potential
to draw different conclusions, uncertainties in the best available
data, the locations for the species based on occurrence records), we
reevaluated all available spatial data and provided an updated
historical distribution map based on Chemsak's (2005, p. 7)
distributional map and observations of only adult male valley
elderberry longhorn beetles (see Current Distribution (since 1997)
section). Based on that analysis, we selected data sets (1) within this
revised distribution; (2) within the past 16 years; and (3) those
records from CNDDB (2013, entire) ranked fair, good, or excellent to
develop a depiction of the presumed extant occurrences map for the
species (see Figure 2), while acknowledging the limitations with these
data. We also incorporated studies documenting the essential life-
history and habitat requirements for both the host plant and the valley
elderberry longhorn beetle, and described the species' distribution in
the context of a metapopulation structure and fragmented habitat.
We then prepared a new summary of the valley elderberry longhorn
beetle's occurrence in the Central Valley and identified the areas of
presumed occupancy based on hydrologic unit as well as geographic
location (see Table 1). For this reevaluation, we did not compare these
areas to those identified at listing. Although evidence of occupancy
(primarily observations of exit holes) for the species has been
documented in additional locations than recorded at the time of listing
in 1980, we believe this is the result of limited data available at the
time of listing and the subsequent surveys that have better defined the
presumed historical range of the valley elderberry longhorn beetle (see
Population Distribution, Presumed Historical Range, and Current
Distribution (since 1997) sections). We acknowledge in this withdrawal
that there are no current estimates of population size or trends in
population numbers for the valley elderberry longhorn beetle, but we
have included and evaluated estimates of occupancy, where available, in
our discussion of population distribution and in our analysis of
threats.
(3) Comment: All four peer reviewers expressed concerns regarding
the accuracy and balance of our review and analysis of factors relating
to threats to the valley elderberry longhorn beetle. One peer reviewer
stated that the proposed rule did not provide accurate and balanced
reviews, and analyses of factors relating to the threats of the
species, and other reviewers stated that a more thorough analysis
incorporating key omissions could result in different conclusions
regarding the threats to the species and population trends.
Specifically, one reviewer recommended that the rule broaden the
discussion of effects of climate change, while two others stated that
potential threats posed by invasive plants should be discussed. One
peer reviewer also stated that a discussion of potential effects of
pesticides and genetic issues was incomplete and possibly misleading.
Two peer reviewers stated that the discussion of threats from Argentine
ants was not adequate in the proposed rule and we did not provide an
accurate assessment of this threat. Finally, another reviewer stated
that there were no analyses of combined threats at each location.
Our Response: In this document, we prepared a revised analysis of
potential threats to the species, and have provided additional or
revised discussions of potential threats related to climate change
effects, as well as invasive plants, pesticides, and predatory ants
(see the specific sections provided under Summary of Factors Affecting
the Species above).
Currently, the best available data do not indicate that genetic
issues are a potential threat to the population structure of the valley
elderberry longhorn beetle, and we are unaware of studies that have
investigated valley elderberry longhorn beetle genetics related to the
population structure described for this species. We also note that
Talley et al. (2006a, p. 7) recommended a systematic geographic
morphological and genetic study to determine the degree of overlap and
interbreeding between valley elderberry longhorn beetle and the
California elderberry longhorn beetle.
(4) Comment: All peer reviewers commented on the limitations of the
30-year-old Recovery Plan (Service 1984) and, therefore, the difficulty
in assessing whether those objectives had been met as discussed in our
proposed rule. The peer reviewers indicated that the delisting criteria
we refer to in the proposed rule (i.e., number of sites and populations
necessary to delist the species) were not established in the Recovery
Plan and the proposed rule does not assess quantitative data from
recent (within the past 2 years) censuses and habitat evaluations to
address an important (interim) recovery objective.
Our Response: We recognize that the Recovery Plan identified only
interim objectives. Because we are withdrawing our proposal to delist
the valley elderberry longhorn beetle, we did not address recovery
objectives, implementation, and evaluation in this document. However,
we will consider the information provided by the peer reviewers,
results from studies and surveys that were not available at the time
the Recovery Plan was written, and our reanalysis of the threats
presented in this document in any revision of the Recovery Plan for the
valley elderberry longhorn beetle.
(5) Comment: All peer reviewers provided examples of conclusions in
the proposed rule that they believe were not supported by the best
available science. Specifically, one peer reviewer stated that no
published studies unambiguously support the continued existence of the
valley elderberry longhorn beetle at no more than 12 locations and that
our evaluation of threats to the species from the nonnative Argentine
ant is contrary to published studies. Another peer reviewer noted that
the conclusions in the proposed rule do not agree with the findings of
Chemsak (2005) for the valley elderberry longhorn beetle, and that this
important reference was not included in the proposed rule. One peer
reviewer stated that we did not include more recent studies and that we
overlooked the concept of habitat dynamics and effects on
metapopulations. Another peer reviewer stated that we disregarded
negative data or conclusions, particularly when these data were limited
to a few sites.
Our Response: In this document, we reevaluated the occurrence data
for the valley elderberry longhorn beetle and developed a new presumed
historical
[[Page 55911]]
range map based on observations of adult males (see our response to
Comments (1) and (2) above). We reviewed the quality and limitations of
occurrence records for the past 16 years and their geographical
locations, and present a revised summary of the locations of these
records based on hydrologic units (see Table 1 in Current Distribution
(since 1997) section) and presumed extant occurrences map (Figure 2).
With regard to Chemsak (2005), we did not have access to this
information during the preparation of the proposed rule because it was
not publicly available, but we were able to locate it from the
publisher and used this reference in preparing our presumed historical
range map (Figure 1). We included a revised discussion of the potential
threats posed to the valley elderberry longhorn beetle from predators
such as the nonnative Argentine ant (see Summary of Factors Affecting
the Species above). In our Background section, we included a more
detailed discussion of the species' habitat and population structure,
including a summary of studies identifying its metapopulation
characteristics.
Following a revised analysis of the best available biological
information, including new information received, and a revised five-
factor analysis of the potential threats to the valley elderberry
longhorn beetle, we concluded that threats related to loss or
modification of additional habitat from levee and flood protection
measures and the effects of climate change, predation, and cumulative
effects of stressors have not been sufficiently reduced; therefore,
delisting is not warranted for this species at this time.
(6) Comment: All of the peer reviewers provided examples of
significant peer-reviewed scientific papers that were not included in
the proposed rule and that they believed would enhance the scientific
quality of our assessment. A total of 11 additional papers were
provided in the peer review report, with Chemsak (2005) being the most
noteworthy example of new information because of its distributional
information for both the valley elderberry longhorn beetle and the
California elderberry longhorn beetle.
Our Response: We were unable to obtain the Chemsak (2005) reference
prior to conducting our analysis for the proposed delisting rule. The
Chemsak (2005) reference is not currently in print, but we were able to
obtain a copy of the relevant sections for the Desmocerus genus in
California from the publisher (Nuckols 2013, pers. comm.). We
georeferenced the distribution maps from this publication for the two
elderberry longhorn beetles and used these results as the starting
point for developing and preparing our presumed historical range map
(Service 2014, GIS Analysis; see also the Presumed Historical Range
section above). While preparing this rule, we also reviewed and
incorporated information from relevant references and studies suggested
by the peer reviewers as well as other studies or survey reports that
were not included in our proposed rule. As stated previously, following
a revised analysis of the best available scientific information,
including the information provided by the peer reviewers, we concluded
that delisting is not warranted for this species at this time (see
Determination section above).
(7) Comment: Peer reviewers provided a number of responses as to
whether we accurately assessed the efficacy of past and ongoing valley
elderberry longhorn beetle management activities relative to its
overall conservation and recovery. One peer reviewer indicated that
management activities are described in detail in the proposed rule, but
stated that estimates of success were based on the amount of habitat
acquired, protected, or restored, rather than monitoring results. The
reviewer also noted that at some of these sites, the valley elderberry
longhorn beetle populations appeared to be declining. Another peer
reviewer highlighted two studies where approximately 25 percent of
suitable habitat was occupied and discussed the potential for incorrect
interpretations in our analyses and findings presented in the proposed
rule when relying on exit holes instead of adult observations. A third
peer reviewer stated that our assessment of the efficacy of management
activities was appropriately addressed, but a fourth peer reviewer said
that we had not done so, and added that we had not adequately monitored
and managed for the valley elderberry longhorn beetle, including
reviewing mitigation reports to evaluate the success of those sites.
Our Response: With regard to restoration, mitigation, and
management activities for valley elderberry longhorn beetle, we
included specific discussions in this document, as well as the
conclusions from studies that evaluated the success of these management
actions (see Restoration and Mitigation Sites in the Background section
and our Factor D discussion of restoration efforts at National Wildlife
Refuges). We also noted there are gaps in monitoring at mitigation
sites and there is a need for better data management, including
locating missing monitoring reports (as described by the review
presented in Holyoak et al. (2010, entire)) that could be important for
future analyses (see Background section). To address the comment
regarding occupancy and interpretation of the data sets using only exit
holes, we summarized estimates of occupancy for the valley elderberry
longhorn beetle (see Population Structure section), and as noted in our
response to Comments 1, 2, 5, and 6, we reviewed the quality and
limitations of occurrence records for the past 16 years and their
geographical locations, and presented a revised summary of the
locations of these records based on hydrologic units (see Table 1 in
Current Distribution (since 1997) section) and presumed extant
occurrences map (Figure 2).
(8) Comment: The peer reviewers indicated that, in general, the
proposed rule was sufficient relative to the level of detail provided.
However, one peer reviewer found the rule contained too much detail on
habitat protection and restoration for sites where the valley
elderberry longhorn beetle has not been reported, while another found
that additional analysis was needed on the potential threat of climate
change.
Our Response: We restructured much of the information presented in
the proposed rule such that irrelevant details were removed and
replaced with new and more relevant information. We presented a new
analysis of the range of the valley elderberry longhorn beetle, while
acknowledging the limitations of the available data and the need to
collect additional information regarding its current abundance and
distribution. We also provided an extensive discussion of climate
change effects in our analysis of threats, and incorporated predictions
from several regional climate models for the Central Valley region. We
incorporated details of results of several studies (e.g.,
metapopulation analysis) and used this information to evaluate the
current threats to the species.
(9) Comment: All peer reviewers found the scientific foundation of
the proposed rule to be fundamentally unsound due to important
omissions, old and missing data, and potentially erroneous conclusions.
The peer reviewers provided several suggestions for improving the
scientific foundation of our analysis prior to making a subsequent
final determination. These include: providing a better evaluation of
the current locations of populations, using specimen records or adult
beetle observations rather than relying on exit holes and old records,
and evaluating the status of the species in a way that incorporates
concepts of
[[Page 55912]]
metapopulation dynamics or spatial ecology.
Our Response: As noted above (see responses to Comments 1, 2, 5,
and 6), this document incorporated new analyses, additional
information, and included a discussion on the population structure (see
Population Structure section) that species experts have defined for the
valley elderberry longhorn beetle. We reevaluated the threats to the
species and concluded that the threats have not been reduced such that
the protections of the Act are no longer necessary. Thus, we determined
that delisting is not warranted for this species, and we are
withdrawing our proposed rule.
(10) Comment: All peer reviewers highlighted several uncertainties
with the data upon which we based our assessment of the current status
of the valley elderberry longhorn beetle in the proposed rule,
including its range and the effects of climate change on the species.
Our Response: We reanalyzed the historical and presumed extant
occurrences of the valley elderberry longhorn beetle (see response to
Comments 1 and 2), while acknowledging the limitations of the available
data and the need to conduct additional studies in order to develop
population trends for this species and its habitat (see Population
Structure Section). As noted above (see response to Comment 8), we also
included an extensive discussion of climate change effects in our
analysis of threats, and incorporated predictions from several regional
climate models for the Central Valley region (see Climate Change
discussion under Factor A above).
County and Local Agency Comments
(11) Comment: Eleven different agencies submitted comments
supporting the proposed rule to delist the valley elderberry longhorn
beetle. The primary reasons for support include:
(a) Conclusions presented in the proposed rule that indicate that
population numbers of the valley elderberry longhorn beetle have
increased to the point where continued Federal protection is no longer
necessary and that the species is now found in more protected
locations.
(b) Monetary and time costs to flood control and other projects
proposed or maintained by these agencies associated with addressing the
regulatory requirements for the federally listed valley elderberry
longhorn beetle, including compliance with the Service's Conservation
Guidelines for the Valley Elderberry Longhorn Beetle (Conservation
Guidelines) (Service 1999, entire), extensive surveys of individual
elderberry shrubs, and mitigation requirements (Mitigation Guidelines
for the Valley Elderberry Longhorn Beetle; Service 1996, entire).
Specific comments on this issue were provided to support their position
such as the need for a flexible and efficient regulatory framework to
facilitate construction of utilities and other projects, and a balance
between habitat conservation policies and public needs (including
publicly funded projects).
(c) The Service recommended delisting the species in its 2006 5-
year review (Service 2006a).
Our Response: Under the Act, we determine that a species is an
endangered or threatened species based on any of five factors: (A) The
present or threatened destruction, modification, or curtailment of its
habitat or range; (B) overutilization for commercial, recreational,
scientific, or educational purposes; (C) disease or predation; (D) the
inadequacy of existing regulatory mechanisms; or (E) other natural or
manmade factors affecting its continued existence. Following our
revised analysis of these factors, including the new information
received during the open comment period related to occupancy estimates
of the valley elderberry longhorn beetle and its occurrence records,
the best available data indicate that the species remains likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range. Thus, we are withdrawing our
proposal to delist the valley elderberry longhorn beetle. Our next 5-
year review will reflect the analyses presented in this rule and any
other new information we receive regarding the status of the species.
We appreciate the comments received citing the monetary and time
costs in response to protections to the valley elderberry longhorn
beetle under the Act. We recognize the need to update our Conservation
Guidelines (Service 1996, 1999) to allow for additional flexibility as
well as to incorporate new information on the species regarding
presumed historical range and scientific studies completed and
published since 1999 that have evaluated threats to the species and its
habitat. We have initiated the process to revise these guidelines in
concert with our reanalysis of our proposed rule. We also appreciate
the willingness expressed by some of the commenters to consider
revising these policies rather than delisting in order to ensure the
recovery of the species and conservation of its habitat. We will
continue to work with local governments, levee districts, and other
entities with responsibilities to maintain flood control structures and
other infrastructure to secure the appropriate permits and
authorizations under the Act when it becomes necessary to maintain the
structures.
(12) Comment: Four agencies submitted comments stating that
maintaining a federally protected status (i.e., as an endangered or
threatened species under the Act) for the valley elderberry longhorn
beetle has created disincentives that inhibit the creation and
protection of elderberry habitat. In other words, the commenters
believe that more habitat would exist for the species without the
protections required under the Act because floodplain management
entities do not want operations and maintenance restrictions that
result from having valley elderberry longhorn beetle within their areas
of responsibility. Three of the agencies stated that naturally
colonized elderberry shrubs (seedlings) are removed and elderberry
plantings are not being included within restoration and mitigation
plans. One of the commenters further stated that delisting the species
would give flood management entities greater flexibility in vegetation
removal, which in turn could allow for increased elderberry shrub
proliferation that may benefit both flood control operation goals and
conservation of the valley elderberry longhorn beetle.
Our Response: We are aware of the opinions provided by these
commenters, and we will continue to work with various agencies to
create or enhance partnerships (see Factor D above) to reduce perceived
disincentives and provide solutions to these issues.
(13) Comment: A commenter stated that the Service's delay in
identifying and removing the valley elderberry longhorn beetle from the
Federal List of Endangered and Threatened Wildlife has eroded public
confidence and support for the species and the Act. The commenter also
stated that, during the development of a post-delisting monitoring
plan, it is imperative that local agencies and private partners
(including local landowners) have an equal voice with Federal and State
agencies so that private property rights and disadvantaged communities
are not unduly and adversely impacted.
Our Response: We appreciate the commenter's feedback regarding our
evaluation process under section 4(a) of the Act. The Act requires us
to use the best commercial and scientific information available to make
determinations as to whether a species
[[Page 55913]]
may be considered endangered or threatened. In this document, we
reevaluated the best scientific and commercial information available
for the valley elderberry longhorn beetle, including peer review
comments on the scientific findings in the proposed rule, agency
comments, and public or other interested party comments, and new
information on occurrences, distribution, and threats to the valley
elderberry longhorn beetle. Our reanalysis of the five factors that
determine if a species meets the definition of endangered or threatened
(according to section 4(a) of the Act) that is presented in this
document indicates that the valley elderberry longhorn beetle continues
to meet the definition of a threatened species (i.e., it is likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range). Thus, we are withdrawing
our proposal to delist the species and ceasing preparation of a post-
delisting monitoring plan, which is no longer appropriate at this time.
(14) Comment: We received a combined comment from two agencies
stating that the removal of the species from the Federal List of
Endangered and Threatened Wildlife would result in larger social and
ecological benefits by enabling the use of limited Federal resources on
other high-priority conservation actions. The commenters referenced the
draft Bay Delta Conservation Plan (BDCP), which is currently under
development. The commenters requested that final action on the proposed
delisting be completed as soon as possible in order to avoid
unnecessary commitments of resources in the development of the BDCP and
with their efforts to comply with Federal and State environmental laws.
Our Response: See response to Comment 11. The Draft BDCP and
associated Draft Environmental Impact Report/Environmental Impact
Statement are being made available to the public for review and comment
for a 228-day review period (December 13, 2013 through July 29, 2014).
We will continue to work with our partners during the development and
finalization of the BDCP.
(15) Comment: One commenter stated they had significant delays in
consulting with the Service on the valley elderberry longhorn beetle,
including performing environmental analyses and complying with
conservation protocols, which they believe greatly lengthened the time
to implement flood protection measures. The commenter also noted that
in those cases where entities choose to mitigate impacts to the valley
elderberry longhorn beetle onsite, the costs of monitoring and
protecting the elderberry plants are ongoing and significant because of
the species' protected status; thus, public entities have a cost
incentive to instead mitigate by purchasing credits offsite. The
commenter stated that this mitigation strategy results in removal of
the species and elderberry from the riparian corridor, which is also a
negative impact for other species that use elderberry in riparian
corridors of the Central Valley. Finally, the commenter stated they
have been supportive of protections for the species including their
demonstrated efforts to restore and mitigate for setback levee
projects.
Our Response: We appreciate the feedback regarding the consultation
process and implementation of mitigation guidelines. We recognize and
appreciate any past, ongoing, and future conservation efforts that may
help conserve valley elderberry longhorn beetle and its habitat.
Federal Agency Comments
(16) Comment: The U.S. Forest Service, Pacific Southwest Region
(Regional Office R5) indicated that, should the valley elderberry
longhorn beetle be delisted, the Forest Service would retain the
species as a Regional Forester's Sensitive Species (for at least 5
years), and it would, therefore, be evaluated relative to any proposed
project within the range of the species or its known habitat. The
agency provided location information for observations of exit holes and
elderberry shrubs within the Region's National Forests (Stanislaus, El
Dorado, and Sierra). The Forest Service also indicated that actions are
taken and would be taken by the agency in the future that provide
protection for the species and its habitat.
Our Response: We appreciate the Forest Service's commitment to
assist in the conservation of the valley elderberry longhorn beetle and
its habitat, regardless of whether the species is delisted. We
requested and received updated (as of 2014) information on elderberry
shrub locations and observations of exit holes, and have used the
information in this document and added it to our GIS database. We note
here that the observation of exit holes within the Sierra National
Forest is outside our presumed historical range for the species (see
Figure 1). Without an observation of an adult male, we cannot confirm
whether this location represents the valley elderberry longhorn beetle
or the California elderberry longhorn beetle.
Public Comments
(17) Comment: Four commenters supported delisting the valley
elderberry longhorn beetle. Reasons for supporting the delisting
included: (a) Conclusions presented in the proposed rule that indicate
population numbers of the valley elderberry longhorn beetle have
increased to the point where continued Federal protection is no longer
necessary and that the species is now found in more protected
locations, and (b) monetary and time costs to flood control and other
projects, with one commenter stating that a delisting decision would
result in significant monetary savings to taxpayers. Specific comments
were also provided regarding the consequences of delays in levee
improvements to ensure the protection of property, and the inability of
property owners to make improvements to their property despite homeless
camps on that same property and the use of elderberry shrubs as
firewood.
Our Response: Under the Act, we determine that a species is an
endangered or threatened species based on any of five factors: (A) The
present or threatened destruction, modification, or curtailment of its
habitat or range; (B) overutilization for commercial, recreational,
scientific, or educational purposes; (C) disease or predation; (D) the
inadequacy of existing regulatory mechanisms; or (E) other natural or
manmade factors affecting its continued existence. Based on our
analysis of these factors, we concluded that the species continues to
warrant listing as threatened (i.e., likely to become endangered in the
foreseeable future within a significant portion of its range under the
Act); thus, we are withdrawing our proposal to delist the species.
We have and will continue to work with local governments, levee
districts, the Corps, and other entities with responsibilities to
maintain flood control structures and other infrastructure to secure
the appropriate permits and authorizations under the Act when it
becomes necessary to maintain the structures. It is a priority for us
to facilitate the safety of communities and farmland protected by
levees, and when we are aware of levee or bridge projects that may
impact the valley elderberry longhorn beetle and its habitat, we work
with the appropriate authorities to secure the necessary permits. We
are aware that homeless camps are established in certain locations in
the Central Valley that contain elderberry habitat. When requested, we
work proactively with
[[Page 55914]]
local governments to manage these complex situations and protect
habitat.
(18) Comment: Five commenters stated that the valley elderberry
longhorn beetle should not be delisted for the following reasons:
(a) The primary threats (e.g., habitat loss) to the valley
elderberry longhorn beetle remain or have increased since listing.
(b) The species has not recovered, its status has not improved
since listing and may be declining, and its range has been reduced
since listing due to loss of habitat. Specifically, there is no
evidence to show that the species has recovered; that is, the inferred
methods to determine occupancy described in the proposed delisting rule
lack the science needed to determine a successful recovery of the
species and, further, the population increase described in the proposed
rule is the result of a greater survey effort and not a real indication
of an actual population size or trend.
(c) Additional locations where evidence of the species has been
observed since listing are not protected, have not been adequately
monitored, and there is evidence of extirpation from some locations due
to complete loss of elderberry habitat. One commenter stated that
records since listing show limited numbers of the species may currently
occupy a limited number of locations, and another commenter noted that
it was incorrect to assume that occurrence records represent existing
populations or that those locations are currently protected.
(d) Many observations of exit holes or adult beetles are old and
may not have correctly identified the species and its status, resulting
in an overestimation of the presence of the species. In addition,
elderberry shrubs may have also been misidentified by environmental
consulting firms conducting surveys for the species or its habitat.
(e) The host plant is not rare or common, but is limited and
discontinuously distributed across the species' range.
(f) The proposed rule is inconsistent with conclusions made by
Talley et al. (2006a, entire) regarding the status of the species and
threats described in that document.
(g) The proposed rule does not provide sufficient estimates of
either: (1) Relative sizes of elderberry habitat areas in individual
sites or regions; or (2) the populations of the beetle, within sites,
or the subspecies as a whole; therefore, the number of beetles in each
local population could be much smaller and, in some locations, may not
be currently occupied at all.
(h) The location information presented in the proposed rule does
not provide details on the extent of the geographical areas (or length
of river systems) and may only represent a point location of a single
elderberry plant or a few plants; large sections in these geographical
locations may have no habitat.
(i) The delisting of the valley elderberry longhorn beetle would
remove the limited protections provided under the Act at many locations
and increase the risk of local extirpation. One commenter stated that
local protections to the species' habitat can be beneficial, but they
do not apply to all (or even most) areas, are uncertain or may be
ineffective, and do not provide a regional approach needed to address
large-scale threats (e.g., climate change) to riparian ecosystems.
(j) The proposed rule assumes that the rarity of the species is
natural and this fact justifies the delisting, but rare species are
more sensitive to threats. One commenter added that, because the
species occurs in regional populations composed of patches of small,
local populations (metapopulation of just a few individuals), their
life history (and survival) is heavily influenced by chance events (see
Background section above).
(k) Threats to the valley elderberry longhorn beetle and its
habitat from the spread of the Argentine ant, an invasive species and
potential predator; specifically, one commenter stated that the
presence of elderberry shrubs does not demonstrate recovery because the
Service has not monitored the presence of these types of predators.
This commenter stated that other studies have shown that similarly
situated beetles, such as the eucalyptus borer (Phoracantha
semipunctata), were found to decline in numbers when present in
locations alongside the Argentine ant.
(l) Threats from invasive, nonnative plants (believed to be
introduced from neighboring development) to the elderberry plant, which
commenters described as an important natural resource for the valley
elderberry longhorn beetle and other wildlife in California's Central
Valley.
(m) Other potential threats to the species including the effects of
climate change, pesticide use, edge effects associated with urban and
agricultural development, inadvertent pruning, and levee maintenance.
(n) An incorrect assumption in the proposed rule that the
appearance of sufficient elderberry meets the habitat requirements of
the valley elderberry longhorn beetle.
(o) Overall lack of scientific rigor in the document and the need
for more rigorous scientific study by knowledgeable species experts to
conclude the success of the Service's recovery efforts.
(p) Lack of acknowledgement of fragmentation of habitat that has
reduced connectivity of habitat, as well as habitat patch size, which
directly affects this species (due to its low mobility, low population
size, and metapopulation structure) and many other species that rely on
contiguous and larger habitat patch sizes or distances for their
survival or recovery.
Our Response: We appreciate the commenters' concerns and
recommendations regarding the need to determine valley elderberry
longhorn beetle persistence and threats that may be impacting the
species, such as activities or conditions (e.g., changes in climate)
that result in habitat loss, nonnative plant invasions, or predation.
In this document, we provided our best estimate of the current
population distribution of the species (see Current Distribution (since
1997) section), but acknowledged the limitations in identifying
occupancy through the amount of elderberry habitat or riparian
vegetation or use of observations of exit holes as evidence of presence
in order to estimate population trends. We also indicated that
population studies are needed to better assess the status of the
species throughout its presumed historical range.
We included in this withdrawal a revised description of the threats
to the species (see Summary of Factors Affecting the Species),
including revised or new discussions of the threats posed by loss of
habitat, levee management, habitat destruction or modification related
to climate change effects, invasive nonnative plants, predation, and
pesticide use. Although literature was not submitted for studies
referenced by one commenter regarding effects to the eucalyptus borer
from the Argentine ant, we included in this withdrawal document
relevant results of a 1992 publication (Way et al. 1992, entire) that
evaluated predation impacts to an arboreal borer (Phoracantha
semipunctata) from the Argentine ant (see Background section above).
As in our proposed rule, we also discuss in this withdrawal the
nearly 90 percent loss of riparian vegetation in the Central Valley,
and the fragmentation of this habitat that has resulted in a locally
uncommon or rare and patchy distribution of the valley elderberry
longhorn beetle within its remaining presumed historical range in the
Central Valley (see Historical Loss of Riparian
[[Page 55915]]
Ecosystems discussion under Factor A). Based on our revised five-factor
analysis of threats, we believe the species continues to meet the
definition of a threatened species (i.e., likely to become an
endangered species in the foreseeable future within a significant
portion of its range), and we are withdrawing our proposal to delist
the species.
(19) Comment: One commenter stated that further clarity of the
definition of what constitutes an elderberry shrub in the Conservation
Guidelines (Service 1999) is needed. The commenter recommended using
the following definition from leading valley elderberry longhorn beetle
researchers: ``In order to be considered a shrub, an elderberry plant
must have one or more stems 1 inch (2.5 cm) or greater in diameter and
for purposes of counting the number of shrubs, a group of shoots that
originates from the same root system or a group of shoots that occurs
within a 16.4 foot (5 m) radius will be considered one shrub.'' [no
citation provided]. In addition, the commenter recommended that we
reevaluate our assessment of the effects of pruning elderberry on the
valley elderberry longhorn beetle, based on the results of studies
presented in Talley and Holyoak (2009). Finally, the commenter
recommended that we consider working with the Valley Elderberry
Longhorn Beetle Collaborative, which is a group of State agencies,
resource managers, researchers, and utilities whose goals are to
improve the viability of the valley elderberry longhorn beetle and
assist the Service in developing more effective mitigation requirements
and improved the Conservation Guidelines.
Our Response: We included a discussion of the study cited in the
comment letter in our Factor A discussion, including additional
information on potential effects of pruning (see Pruning section under
Factor A). As noted in our response to Comment 11 above, we initiated
the process to revise these guidelines in concert with our reanalysis
of the proposed rule. Finally, we appreciate the recommendation
provided regarding the opportunity to work with our partners and the
Valley Elderberry Longhorn Beetle Collaborative, and we look forward to
working as a team to develop conservation measures that benefit the
recovery of the species.
(20) Comment: One commenter recommended that we conduct a thorough
inventory of all current and recent conservation, restoration, and
mitigation activities affecting the species and its habitat within the
Central Valley, as well as an analysis of likely future actions under
such broad programs as the Central Valley Flood Protection Plan and the
BDCP.
Our Response: We agree that the commenter's recommendations for
surveys and an accounting of various conservation, restoration, and
mitigation activities (including the Central Valley Flood Protection
Plan and BDCP) would provide more information that would be helpful in
future evaluations of the status of the species, and we will consider
this information in future conservation planning efforts, including any
future revisions to the species recovery plan.
(21) Comment: A natural lands management organization stated that,
based on the information they have collected or reviewed pertaining to
the preserves they manage in the Central Valley, uncertainty remains
about the stability of the valley elderberry longhorn beetle within
this part of its range. The commenter provided information on the
status of the valley elderberry longhorn beetle and its habitat, based
on the management and the experience of their preserve managers, and
identified potential threats to elderberry habitat in these areas and
the need for additional funding to support specific management
activities that benefit the species.
Our Response: We appreciate the information provided by the
organization regarding the preserves they manage and the status of the
species in these areas. We incorporated this information in the
Background section of this rule and used this information in our
reanalysis described in this document, including the Summary of Factors
Affecting the Species.
(22) Comment: A manager of a valley elderberry longhorn beetle
conservation bank provided information on plantings of elderberry
shrubs (and associated plants) stating that adult valley elderberry
longhorn beetles have yet to be seen adjacent to or within the
conservation bank, despite these restoration efforts. The commenter
also submitted opinions regarding the approach to recovery efforts that
has focused, in part, on providing elderberry habitat for the species
(``build it and they will come'') rather than cultivation and
disbursement of transplanted elderberry shrubs from project sites to
conservation banks, especially those assumed to contain exit holes.
Our Response: We appreciate the personal observations provided
regarding the occupancy of the valley elderberry longhorn beetle at
this conservation bank. We will consider the commenters'
recommendations regarding focusing recovery efforts on elderberry
cultivation and disbursement as we revise the Conservation Guidelines
(Service 1996), and revise the recovery plan for the valley elderberry
longhorn beetle.
(23) Comment: One commenter stated that the peer review report
(Atkins 2013, entire) did not accurately represent the science and did
not adequately summarize the peer reviewer comments. The commenter also
cited concerns with a recommendation by one of the peer reviewers
regarding the use of pheromones as a method to evaluate the status of
the species (through the attraction of adult male beetles), noting its
use has not been shown to be effective on this subspecies and that
conclusions drawn would not provide information on habitat loss; thus,
direct observations should still be considered.
Our Response: We requested a peer review of the valley elderberry
longhorn beetle proposed rule and were provided individual comments
from each peer reviewer as well as a summary of the overall
(collective) peer review evaluation. This withdrawal incorporated this
information and addresses both the collective and individual comments
provided by the peer reviewers (see response to Comments 1 through 10
above). We included in this withdrawal a summary of preliminary results
from pheromone studies (e.g., Ray et al. 2012, entire; Arnold 2013,
entire; see Background section above). In our Determination section, we
note that a second year of trial surveys using pheromones is currently
under way (Sanchez 2014, pers. comm.) to further evaluate the efficacy
of this method in evaluating populations of the valley elderberry
longhorn beetle within parts of its presumed range.
(24) Comment: One commenter expressed concerns regarding the
Service's rule-making process used to prepare the proposed delisting
rule, including our internal review process, pointing out discrepancies
in the proposed rule with previous Service documents. The commenter
concluded that the only course of action was to publish a finding that
delisting was not warranted and prepare a new 5-year review, revise the
current Recovery Plan, update the Conservation Guidelines (Service
1999), and consider redesignation of critical habitat to a much broader
area, including both occupied and unoccupied habitat that may be
important to reducing the fragmentation effect of the species' current
habitat.
Our Response: Under the Act, we determine that a species is an
endangered or threatened species based
[[Page 55916]]
on any of five factors: (A) The present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. Our analysis of these factors in
this document shows that the species continues to meet the definition
of a threatened species (i.e., likely to become an endangered species
in the foreseeable future throughout all or a significant portion of
its range). Therefore, we are withdrawing our proposal to delist the
species.
We recognize the need for additional actions regarding the valley
elderberry longhorn beetle (e.g., revision of the Conservation
Guidelines (Service 1996)). We will take into consideration various
conservation-related recommendations provided by the commenter when
conducting the next 5-year review and during any revision of a recovery
plan for the species. In addition, we have initiated the process to
revise the Conservation Guidelines concurrent with our reanalysis of
the best available information presented in this document.
(25) Comment: One commenter stated that much more information,
particularly with regard to population stability in multiple areas, is
needed than currently exists to determine a proposed delisting for this
species. The commenter noted the delisting rule repeatedly states there
are minimal surveys and data uncertainties making it difficult at this
time to make a determination of the species' population status;
however, the delisting document simultaneously acknowledges and ignores
these information gaps. The commenter stated there is no scientific
evidence that the geographic range of the valley elderberry longhorn
beetle has expanded nor is there evidence that populations within
locations have increased since listing. The commenter further explained
that, because the species is naturally rare and occurs only in small,
local populations with just a few individuals within any one site,
increases of individuals within sites would not necessarily be expected
if recovery was occurring. The commenter indicated, while restoration
efforts have created or enhanced some of the lost riparian vegetation,
only a fraction of a percent of what was historically lost has been
provided, and that long-term trends of the species' population
structure throughout its range are still needed to determine whether
its populations are persistent, resilient, resistant, and not variable.
Our Response: As noted in our response to Comments 1 and 2, in our
Background section we reevaluated the occurrence records, incorporated
a discussion of the metapopulation structure and limited dispersal
ability of the species, and presented a discussion of the success of
elderberry restoration and mitigation sites. We also revised our
threats analysis (see Summary of Factors Affecting the Species) in this
withdrawal, including the effects of levee maintenance, pruning, and
climate change, invasive plants, and predation. Our analysis of these
factors shows that the species continues to warrant listing as a
threatened species, and we are withdrawing our proposal to delist the
species.
(26) Comment: One commenter stated that, regardless of the final
decision regarding delisting, the Service needs to revise its
Conservation Guidelines (Service 1999) by incorporating new data on
pruning, topping, roadside dust and noise, transplanting, and spatial
relationships between the valley elderberry longhorn beetle, its
habitat, and environmental stochasticity (random processes or events),
which can affect its populations. The commenter suggested that the
Service should then bring diverse land users together and
collaboratively work with them to develop a priority list of additional
research necessary to determine the status of the species.
Our Response: As noted above (see response to Comment 11), we have
initiated the process to revise our Conservation and Mitigation
Guidelines (Service 1996, 1999).
(27) Comment: One commenter stated that the agency's actions are
contrary to law (Administrative Procedure Act) because the agency did
not consider alternatives to delisting the valley elderberry longhorn
beetle. The commenter believes that the Service should consider
downlisting the valley elderberry longhorn beetle from endangered to
threatened given the potential threats of the Argentine ant to
populations of the species. The commenter stated that downlisting the
beetle from endangered to threatened would allow researchers to
undertake a more detailed study of the effects of the Argentine ant on
beetle populations, but would still allow for protection under the Act
as well as accommodate the concerns of others regarding impacts to
economic activity.
Our Response: The species is currently listed as a federally
threatened, not endangered, species under the Act (45 FR 52803; August
8, 1980); therefore, we do not have the option of downlisting to
threatened. We issued the proposed rule (77 FR 60238; October 2, 2012)
to remove the valley elderberry longhorn beetle as a threatened species
from the List of Endangered and Threatened Wildlife and to remove the
designation of critical habitat. This document withdraws that proposed
rule because the best scientific and commercial data available,
including our reevaluation of information related to the species'
range, population distribution, and population structure, indicate that
threats to the species and its habitat have not been reduced such that
removal of this species from the Federal List of Endangered and
Threatened Wildlife is appropriate.
(28) Comment: One commenter stated that the current Recovery Plan
(Service 1984) does not address the steps being taken to curb predation
from the Argentine ants and instead regards the absence of data as a
justification for inaction. As a result, the commenter believes that
the current Recovery Plan does not meet the delisting requirements of
the Act.
Our Response: We acknowledge the need to update the Recovery Plan,
which was prepared in 1984, and the need for the Recovery Plan to
address additional threats discussed in this document, as well as new
information on the species' distribution. We will consider new
information and recommendations provided by commenters when we update
the Recovery Plan in the future.
(29) Comment: One commenter from East Sacramento, California,
stated that he has a red elderberry shrub in his backyard and that he
has photographed the valley elderberry longhorn beetle on his property
on several occasions (three photos were submitted with the comments).
The commenter believes his observations give the appearance that the
species has a more varied range than what we stated in the proposed
delisting rule. The commenter stated that we should determine if his
observations are of the valley elderberry longhorn beetle and thus
represent a range expansion, and that, if it is found in elderberry in
other backyards throughout the Sacramento Valley, then the species may
not warrant protection under the Act.
Our Response: We appreciate the beetle observations provided by the
commenter. Although the images submitted were slightly out of focus, we
requested a species expert review the photos and confirm the identity
of the insect. We believe the photos submitted are of Podabrus
pruinosus, a common
[[Page 55917]]
cantharid beetle that is part of a family of beetles frequently
referred to as soldier or leather winged beetles; adults of this
species are commonly observed in spring and summer and are known to
occur in the Central Valley (Arnold 2014c, pers. comm.).
(30) Comment: One commenter provided personal observations of
elderberry habitat and its use based on the commenter's farming
experience along the Tuolumne River. The commenter stated that his
property was inundated with elderberry plants and he observed birds
carrying berries (seeds) that were deposited along fences or buildings.
The commenter also noted that elderberry roots spread extensively
underground and characterized elderberry plants as weeds that
interfered with structures on his property.
Our Response: We assume that the commenter provided these comments
in order to provide historical information on the amount of elderberry
habitat in this area and wildlife use of elderberry plants. In this
document, we summarized studies of elderberry characteristics that are
important to the life history of the valley elderberry longhorn beetle
(see Background section). We used this information in conjunction with
reported estimates of low occupancy and our estimates of current
elderberry habitat within the presumed historical range of the valley
elderberry longhorn beetle, and analyzed the threats to the species. We
concluded, based on the best scientific available information, that the
valley elderberry longhorn beetle continues to warrant listing as
threatened, and we are withdrawing our proposal to delist the species.
References Cited
A complete list of all references cited in this document is
available on the Internet at http://www.regulations.gov at Docket No.
FWS-R8-ES-2011-0063 or upon request from the Field Supervisor,
Sacramento Fish and Wildlife Office (see ADDRESSES section).
Authors
The primary authors of this document are the staff members of the
Carlsbad Fish and Wildlife Office and the Pacific Southwest Regional
Office.
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: August 29, 2014.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2014-21585 Filed 9-16-14; 8:45 am]
BILLING CODE 4310-55-P