[Federal Register Volume 79, Number 184 (Tuesday, September 23, 2014)]
[Proposed Rules]
[Pages 56686-56704]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-22063]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R5-ES-2014-0021; FXES11130900000C6-123-FF09E30000]
RIN 1018-AY83
Endangered and Threatened Wildlife and Plants; Proposed Rule To
Remove the Delmarva Peninsula Fox Squirrel From the List of Endangered
and Threatened Wildlife
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule; availability of draft post-delisting monitoring
plan.
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SUMMARY: Under the authority of the Endangered Species Act of 1973, as
amended (Act), we, the U.S. Fish and Wildlife Service (Service),
propose to remove the Delmarva Peninsula fox squirrel (Sciurus niger
cinereus), more commonly called the Delmarva fox squirrel (DFS), from
the Federal List of Endangered and Threatened Wildlife due to recovery.
This proposed action is based on a thorough review of all available
information, which indicates that the subspecies is now sufficiently
abundant and distributed to withstand current and foreseeable threats
to its long-term viability and thus no longer meets the definition of a
threatened species or an endangered species under the Act.
We are also providing notification that a draft post-delisting
monitoring (PDM) plan is available for public review. We are seeking
information and comments from the public on this proposed rule and the
PDM plan.
DATES: We will accept comments received or postmarked on or before
November 24, 2014. Comments submitted electronically using the Federal
eRulemaking Portal (see ADDRESSES below) must be received by 11:59 p.m.
Eastern Time on the closing date. We must receive requests for public
hearings, in writing, at the address shown in FOR FURTHER INFORMATION
CONTACT by November 7, 2014.
ADDRESSES: You may submit comments by one of the following methods:
Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. Follow the instructions for submitting comments to
Docket No. FWS-R5-ES-2014-0021. Then, in the Search panel on the left
side of the screen, under the Document Type heading, click on the
Proposed Rules link to locate this document. You may submit a comment
by clicking on ``Send a Comment or Submission.''
By hard copy: Submit by U.S. mail or hand-delivery to: Public
Comments Processing, Attn: FWS-R5-ES-2014-0021, U.S. Fish & Wildlife
Headquarters, MS: BPHC, 5275 Leesburg Pike, Falls Church, VA 22041-
3803.
We will post all comments on http://www.regulations.gov. This
generally means that we will post any personal information you provide
(see the Public Comments section below for more information).
Copies of Documents: The proposed rule, draft post-delisting
monitoring plan, and primary supporting documents are available on
http://www.regulations.gov. In addition, the supporting file for this
proposed rule will be available for public inspection, by appointment
during normal business hours, at the Chesapeake Bay Field Office, 177
Admiral Cochrane Dr., Annapolis, MD 21401, 410-573-4573, and on the
Chesapeake Bay Field Office Web site at: http://www.fws.gov/chesapeakebay/. Individuals who use a telecommunications device for the
deaf (TDD) may call the Federal Information Relay Services (FIRS) at
800-877-8339.
FOR FURTHER INFORMATION CONTACT: Questions or requests for additional
information may be directed to Genevieve LaRouche, Field Supervisor, by
telephone at 410-573-4573, or Cherry Keller, Wildlife Biologist, by
electronic mail at cherrykeller@fws.gov or by telephone 410-
573-4532. Individuals who are hearing-impaired or speech-impaired may
call the Federal Relay Service at 800-877-8337 for TTY assistance.
SUPPLEMENTARY INFORMATION:
Executive Summary
Purpose of Regulatory Action
We propose to remove the Delmarva fox squirrel from the Federal
List of Endangered and Threatened Wildlife (50 CFR 17.11) due to
recovery. This proposed action is based on a thorough review of the
best available scientific and commercial information as assessed in two
5-year status reviews conducted in 2007 and 2012. These reviews, along
with additional information that has become available since 2012,
indicate that current threats to the Delmarva fox squirrel have been
sufficiently abated and that the subspecies is now sufficiently
abundant and widely distributed to withstand any foreseeable threat to
its long-term viability. It therefore no longer meets the definition of
a threatened species or an endangered species under Act. This document
thus consists of: (1) A proposed rule to delist the Delmarva fox
squirrel; and (2) a notice of availability of a draft post-delisting
monitoring plan.
Basis for Finding
Under the Endangered Species Act, a species may be determined to be
endangered or threatened 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. We must consider the same
factors in delisting a species. We may delist a species if the best
scientific and commercial data indicate the species is neither
threatened nor endangered for one or more of the following reasons: (1)
The species is extinct, (2) the species has recovered and is no longer
threatened or endangered, or (3) the original scientific data used at
the time the species was classified were in error.
The Delmarva Peninsula fox squirrel was listed as federally
endangered in 1967, because its distribution had
[[Page 56687]]
contracted to only 10 percent of its historical range. The most likely
causes for this decline were loss of mature forest from land clearing
for agriculture, short-rotation timber harvest, and overhunting.
After reviewing all available scientific and commercial
information, we find that delisting the Delmarva fox squirrel due to
recovery is warranted for the following reasons:
(1) As a result of translocations and discovery of additional
natural populations, the known distribution of DFS has expanded since
listing, and its range now extends over 28 percent of the Delmarva
Peninsula. Acres of occupied forest and average density estimates lead
to an overall estimate of 17,000 to 20,000 DFS distributed across the
subspecies' current range.
(2) The primary threats to the species' viability, including
habitat loss due to development, timber harvest, and sea level rise, no
longer pose either a current or foreseeable risk of DFS extinction,
based on the following findings:
Most development on the Delmarva Peninsula is projected to
occur around several large cities outside the DFS's current occupied
range, and existing laws and programs are directing development into
agricultural land and out of forest land. Further, within the
squirrel's current range, land protection is occurring at a more rapid
rate than the rate of development. Within the current range, about 30
percent of DFS-occupied forest is now protected from development (USFWS
2012, table 5), comprising approximately 16,187 hectares (ha) (40,000
acres (ac)) of protected and occupied forest.
Timber harvest rates and the size of individual cuts are
decreasing over time, and remote sensing data indicate that sufficient
acres of mature forest have remained on the landscape even with past
harvest rates. In addition, 23,472 ha (58,000 ac) of forest land
previously managed for pulpwood--and thereby precluded from maturing
into DFS habitat--are now being managed by the State of Maryland for
sawtimber and wildlife values, including DFS conservation; this
management plan is expected to continue over the foreseeable future.
Although sea level rise is projected to eventually affect
the largest extant population of DFS, the associated habitat losses are
not expected to cause its extirpation. This DFS population, which is
over 70 times the minimum viable population size, is likely to expand
into more inland forests via riparian and other connecting corridors.
Further, despite impacts to this area and other localized habitat
areas, over 80 percent of the squirrel's range is not vulnerable to a
foreseeable sea level rise of 0.61 meter (m) (2 feet (ft)).
Based on a 40-year track record, it is apparent that State
laws and programs in Maryland, Delaware, and Virginia will continue to
provide for forest habitat and wildlife conservation, including
preventing the return of overhunting of DFS, following delisting.
Taking into consideration the current and projected rangewide
population viability of the DFS and availability of suitable habitat,
our overall conclusion is that this species is no longer in danger of
becoming extinct, nor is it likely to once again become endangered in
the foreseeable future.
Information Requested
We intend that any final action resulting from this proposed rule
will be based on the best scientific and commercial data available and
be as accurate and effective as possible. Therefore, we invite tribal
and governmental agencies, the scientific community, industry, and
other interested parties to submit comments or new data, if any,
regarding this proposed rule. In particular, we are seeking information
and comments concerning: (1) The continued presence, extirpation, or
new locations of DFS colonies within the subspecies' historical range;
(2) our analysis of the viability of DFS populations; (3) our analysis
of the factors likely to affect the long-term status of the squirrel,
especially development, forestry, and sea-level rise projections for
the Delmarva Peninsula; and (4) our proposed post-delisting monitoring
program for the DFS.
Please bear in mind that comments simply advocating or opposing the
proposed action without providing supporting information will be noted
but not considered in making a determination, as section 4(b)(1)(A) of
the Act (16 U.S.C. 1531 et seq.) directs that determinations as to
whether any species is a threatened or endangered species shall be made
``solely on the basis of the best scientific and commercial data
available.''
To issue a final rule to implement this proposed action, we will
take into consideration comments and any additional information
received within the public comment period. Such communications may lead
to a final rule that differs from this proposal. All comments provided
to us, including commenters' names and addresses, will become part of
the supporting record.
You may submit your comments and supporting materials concerning
the proposed rule by one of the methods listed in ADDRESSES. We will
not accept comments sent to an address not listed in ADDRESSES. All
comments must be submitted to http://www.regulations.gov, hand
delivered, or postmarked by the deadline specified in DATES.
We will post your entire comment, including your personal
identifying information, on http://www.regulations.gov. Individuals
wishing to withhold personal identifying information, such as street
address, phone number, or email address, must make this request
prominently at the beginning of the comment document. Please note,
however, that we cannot guarantee that we will be able to comply with
such requests. We will always make submissions from organizations and
businesses, and from individuals identifying themselves as
representatives or officials of organizations or businesses, available
for public inspection in their entirety.
Comments and materials we receive, as well as supporting
documentation used in preparing this proposed rule, will be available
for public inspection on http://www.regulations.gov or by appointment
during normal business hours at the Service's Chesapeake Bay Field
Office (see FOR FURTHER INFORMATION CONTACT).
Peer Review
In accordance with our policy, ``Notice of Interagency Cooperative
Policy for Peer Review in Endangered Species Act Activities,''
published on July 1, 1994 (59 FR 34270), we will seek the expert
opinion of at least three appropriate independent specialists regarding
scientific data and interpretations contained in this proposed rule. We
will send copies of this proposed rule to the peer reviewers
immediately following publication in the Federal Register. The purpose
of such review is to ensure that our decisions are based on
scientifically sound data, assumptions, and analysis. Accordingly, the
final decision may differ from this proposal.
Background
Regulations published at 50 CFR part 424 specify the procedures and
requirements for adding or removing species from the List of Endangered
and Threatened Wildlife (50 CFR 17.11). The Secretary of the Interior
has delegated responsibility to the Service for determining whether a
species should be removed from any List published pursuant to section
4(c) of the Act. We are additionally required by section
[[Page 56688]]
4(c)(2) and 50 CFR 424.12 to review each species on the List every 5
years (i.e., conduct a 5-year review) to determine whether a species'
classification under the Act is accurate. In the course of a 5-year
review, we evaluate whether the species continues to meet the legal
definition of a threatened or endangered species, based upon the
species' biological status and its status relative to the five factors
under section 4(a)(1). These factors encompass the following extinction
risks: (A) The present or threatened destruction, modification, or
curtailment of the species' habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; and (E) other natural or manmade factors affecting the
species' continued existence. A species may be delisted pursuant to 50
CFR 424.11(d) if the best available scientific and commercial data
substantiate that the species is neither endangered nor threatened for
one or more of the following reasons: The species is considered to be
extinct, the species is considered to be recovered, or the data
available when the species was listed (or the interpretation of those
data) were in error.
This proposed rule is based upon information contained in, and the
recommendation of, a 5-year review for the DFS that was initiated on
August 4, 2010 (75 FR 47025), and approved on September 4, 2012 (USFWS
2012). The review, which assessed the DFS's status across its entire
range, concluded that the subspecies is now sufficiently abundant and
distributed to withstand current and foreseeable threats to its long-
term viability, and that, therefore, the subspecies does not meet the
definition of either an endangered species or a threatened species
under section 3 of the Act, based on recovery. The entire review is
available at http://www.fws.gov/northeast/EcologicalServices/recovery,
and on the Chesapeake Bay Field Office Web site: http://www.fws.gov/chesapeakebay.
Previous Federal Actions
The Delmarva Peninsula fox squirrel was listed as an endangered
species throughout its known historical range on March 11, 1967 (32 FR
4001). At that time, critical habitat was not provided for under the
Act; hence, critical habitat was not designated for the DFS.
On September 13, 1984 (49 FR 35951), a translocated DFS population
released on the Assawoman Wildlife Management Area in Sussex County,
Delaware, was designated as an experimental nonessential population.
Notably, this was the first experimental population designated under
the Act.
The original recovery plan for the DFS was approved on November 6,
1979. The recovery plan was subsequently revised in January 1983, with
a second revision on June 8, 1993. On October 31, 2003, the second
revision of the recovery plan was updated to include new status
information and clarify the recovery criteria for the DFS.
The DFS was included in three cursory 5-year reviews conducted for
all listed species from 1979 to 1991, including a 1979 (44 FR 29566)
review of all species listed prior to 1975; a 1985 (50 FR 29901) review
of all species listed before 1976 and in 1979 and 1980; and a 1991 (56
FR 56882) review of all species listed before 1991. None of these
reviews resulted in a recommendation to change the listing status of
the DFS.
The first comprehensive and species-specific 5-year review for the
DFS was completed in 2007 (USFWS 2007). This review recommended
reclassification of the DFS from endangered to threatened status,
pending further analysis of forest and development patterns on the
Delmarva Peninsula. The second comprehensive 5-year review for the
subspecies was completed in 2012; its recommendation to delist the DFS
forms the basis for this proposed rule.
Further information on Federal actions for the DFS can be found on
the Service's Environmental Conservation Online System (ECOS) at:
http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=A00B.
Biological Background
The Delmarva fox squirrel (Sciurus niger cinereus) is a subspecies
of eastern fox squirrel (Sciurus niger) found only on the Delmarva
Peninsula. The Delmarva Peninsula is located between the Chesapeake Bay
and Atlantic Ocean and covers portions of Maryland, Delaware, and
Virginia. The DFS is a large, silver-gray tree squirrel with white
underparts and a wide tail. It can be easily distinguished from the
gray squirrel (Sciurus carolinensis), the only other tree squirrel in
the area, by its larger size, wider tail, short ears, and silver-gray
color. The DFS inhabits mature forests of mixed hardwoods and pines
within the agricultural landscapes of the Delmarva Peninsula and is not
typically found in suburban settings. These mature forests provide
abundant crops of acorns, pine cones, and other food as well as
cavities for dens. DFS are also associated with forests that have a
more open understory (Dueser et al. 1988, entire; Dueser 2000, entire)
or where understory shrubs are clumped, leaving other open spaces
(Morris 2006, p. 37). DFS use a wide range of mixed forest types that
may be dominated by hardwoods or conifers. While they need mature
forest, their diets are diverse and they travel and forage in many
areas, including clearcuts, young forests, and agricultural fields.
As members of the Order Rodentia, DFS have life histories with good
potential for population increase; for example, females breed at 1 year
of age, litter sizes range from 2 to 4 young, some females have
potential for 2 litters in 1 year, and lifespans can reach 6 to 7 years
in the wild. Den sites are frequently found in hollow portions of
trees, but leaf nests may be used as well. Home ranges of DFS vary
considerably but are typically 12 to 16 ha (30 to 40 ac), and
individual home ranges overlap (Flyger and Smith 1980; entire, Paglione
1996; entire, Pednault-Willett 2002, p. 109). Densities range from 0.36
to 1.29 DFS per ha (0.15 to 0.5 DFS per ac), averaging 0.82 DFS per ha
(0.33 DFS per ac) (Paglione 1996, p. 28; Pednault-Willett 2002, pp. 85-
104).
Historically, this species was patchily distributed throughout most
of the Delmarva Peninsula and into southern Pennsylvania, but by the
time of listing the remnant populations occurred in only four Maryland
counties (Taylor 1976, entire); this range contraction was most likely
due to land use changes and hunting. When the subspecies was listed in
1967, its distribution had been reduced to only 10 percent of the
Delmarva Peninsula. After listing, the hunting season was closed and
recovery efforts focused on expanding the squirrel's distribution
through translocations, thereby decreasing its vulnerability to
extinction. In addition, new populations have been discovered since the
time of listing (particularly since more intensive search efforts were
initiated), and there are now many more areas of forest known to be
occupied by DFS.
The squirrel's current occupied range is defined as the area within
4.8 kilometers (km) (3 miles (mi)) of credible DFS sightings. As of the
2012 5-year review, this covered 28 percent of the Delmarva Peninsula,
including 10 of the 14 peninsular counties (8 counties in Maryland and
1 each in Delaware and Virginia) and 54,543 ha (134,778 ac) of occupied
forest (USFWS 2012, based on 2010 data). Since that time, new sightings
have continued to occur and an updated overview of the range as of 2013
is provided in table 1. An additional population discovered in
Worcester County, Maryland, is the first population found there that
was not a result of a translocation. Figure 1 shows
[[Page 56689]]
range changes from the time of the 1993 recovery plan to the present.
Table 1--Known Occupied Range of the DFS, 1970 to 2013
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Year (approximate date for the data)
Occupied range --------------------------------------------------------------------------------------------------------------------
~ 1970 1990 2005 2010 2013
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Number of counties in the range 3..................... 3..................... 6.................... 6.................... 7
(without translocations).
Number of counties in the range 4..................... 10.................... 10................... 10................... 10
(with translocations).
Total acres of occupied forest N/A................... 103,311............... 128,434.............. 134,778.............. 137,363
rangewide.
Percent of historical range 10.................... ...................... 27................... 28................... 28
occupied.
Source............................. Taylor and Flyger 1974 USFWS 1993, recovery USFWS 2007, 5-yr USFWS 2012, 5-yr USFWS 2013 data
plan. review. review.
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BILLING CODE 4310-55-P
[[Page 56690]]
[GRAPHIC] [TIFF OMITTED] TP23SE14.000
BILLING CODE 4310-55-C
Recovery Criteria
Determinations to remove species from the List must be made in
accordance with sections 4(a)(1) and 4(b) of the Act. Section 4(a)(1)
requires that the Secretary determine if a species is endangered or
threatened because of one or more of five threat factors. Section 4(b)
of the Act requires that the determination be made ``solely on the
basis of the best scientific and commercial data available.''
Recovery criteria, as required by section 4(f)(1)(B)(ii) of the
Act, help guide recovery efforts and act as triggers for when it might
be appropriate to undertake a review of the status of a listed species;
however, the ultimate determination of whether to reclassify or delist
a species must be made in accordance with statutory standards. Thus,
although recovery criteria should always be considered when making
listing decisions for listed species, they can neither substitute for
nor pre-empt 4(a)(1) determinations and the regulations promulgated
under this section of the Act. Ultimately, a decision to remove a
species from the
[[Page 56691]]
Federal List of Endangered and Threatened Wildlife is made when the
best available data show that the species is no longer an endangered
species or a threatened species, regardless of how closely this
information conforms to the information and criteria in the recovery
plan.
The following discussion provides a brief review of the current
recovery plan for the DFS, as well as an assessment of the plan's
objectives and criteria as they relate to evaluating the status of this
subspecies.
The most recent DFS recovery plan was approved by the Service on
June 8, 1993 (USFWS 1993, entire), and updated on October 31, 2003
(USFWS 2003, entire). The plan states that ``the long-range objective
of the DFS recovery program is to restore this endangered species to a
secure status within its former range.'' The plan provides three
criteria for reclassifying the DFS from endangered to threatened
status. It then provides four additional criteria to be considered in
conjunction with the first three for delisting the DFS.
Criterion 1: Ecological requirements and distribution within the
remaining natural range are understood sufficiently to permit effective
management. A considerable body of new information has been obtained
regarding DFS distribution and ecological requirements, and we thus
conclude that this recovery criterion has been met. The six key
contributions to our understanding of the DFS are summarized below.
DFS range and distribution. The geographic information system (GIS)
maintained for the DFS documents a significant increase in the area
occupied by DFS since the 1993 recovery plan was issued (see figure 1
above). Records of DFS sightings by knowledgeable observers and, in
particular, the use of trap and camera surveys have greatly improved
our ability to determine which forest tracts are occupied by the DFS
and to determine continued DFS presence in these areas.
Population persistence. Persistence of DFS populations over the
recovery period has been evaluated through comparison of occupancy over
time (USFWS 2012, pp. 15-17). A 1971 survey of 101 sites within the
historic range of the DFS identified 65 sites as occupied and 36 sites
where the DFS was determined to be absent based on frequent site visits
(Taylor and Flyger 1974, entire). This survey was repeated in 2001
(Therres and Willey 2005, entire) and showed that the DFS persisted at
60 of the 65 sites (92 percent) identified as occupied in 1971, was
extirpated from 5 sites, and had colonized 11 sites; thus, the DFS was
considered to be stable to slightly increasing in the area surveyed.
A second analysis compared DFS persistence in woodlots known to be
occupied in 1990 to its occupancy status through 2010 (USFWS 2012, pp.
7-17). As of 1990, the DFS was recorded on 275 Maryland forest tracts
comprising 41,720 ha (103,125 ac). Records from 1998 to 2010 indicate
that the DFS continued to occupy at least 91 percent of the 41,720 ha
(encompassing 181 forest tracts) and was extirpated from 1 percent of
these hectares (7 tracts). The occupied forest tracts where DFS persist
are widely distributed across the known 1990 range (USFWS 2012, figure
4). Occupancy was deemed uncertain on 87 of the 275 tracts due to
difficulty in accessing properties or lack of data (table 2). Noting
that because woodlots range in size, the acreage of occupied forest is
thought to be a better parameter than number of tracts, if we
nevertheless consider the 188 woodlots that can be classified as
persisting or extirpated, 96 percent were persisting and only 4 percent
were extirpated.
Table 2--DFS Occupancy of 275 Forested Tracts (41,733 ha or 103,125 ac) in Maryland, 1990 Compared to 2010
----------------------------------------------------------------------------------------------------------------
Percent of the
original
41,733 ha
Occupancy change from 1990 to 2010 Area of forest Number of (103,125 ac)
forest tracts in each
occupancy
status
----------------------------------------------------------------------------------------------------------------
Persistence................................... 38,130 ha (94,221 ac)........... 181 91
Extirpations.................................. 499 ha (1,233 ac)............... 7 1
Uncertain\.................................... 3,104 ha (7,671 ac)............. 87 8
Discoveries or colonizations.................. 13,042 ha (32,227 ac)........... 250 ..............
----------------------------------------------------------------------------------------------------------------
As of 2010, an additional 13,042 ha (32,227 ac) of DFS-occupied
forest had been reported in all three States (USFWS 2012, p. 8).
Although some of these discoveries are likely to be occurrences that
were previously present but undetected, anecdotal information indicates
that several new localities represent true range expansion. For
instance, there are several locations where landowners living at a site
for 25 years or more have reported seeing DFS only in the past decade
(USFWS 2012, figure 4). Further, at one site in Caroline County,
Maryland, DFS were observed 5 years after two seasons of negative
trapping results, providing strong evidence for establishment of a new
colony. The population on the Nanticoke Wildlife Management Area in
southwestern Delaware is also likely a new colonization, given that
State biologists had been working at this site for many years without
observing DFS. As of 2010, forest areas with persisting or newly
discovered DFS occurrences, plus occurrences awaiting confirmation,
totaled 54,276 ha (134,119 ac) in Maryland alone. Using the 2010
figures for occupied forest in all three States, as well as maps of
mature forest and density estimates of DFS available from various
studies, we estimate that the total population of DFS is now about
20,000 animals across an expanded range (USFWS 2012, p. 21).
Population viability. A DFS population viability analysis (PVA)
developed by Hilderbrand et al. (2007, entire) used environmental
variability associated with demographic features of natural populations
(fecundity and survivorship) to model the extinction probabilities of
populations of different sizes. This PVA determined that a population
with 65 females, or 130 animals total, had a 95 percent chance of
persisting for 100 years. This value was described as a minimum viable
population (MVP) and was used to gauge extinction risk by projecting
how many MVPs are likely to be present in a given portion of the
current DFS range (USFWS 2012, pp. 18-20).
Using dispersal parameters and existing data on DFS movements, the
PVA also estimated that 75 percent of a given DFS population would have
the ability to disperse to areas within 4 km
[[Page 56692]]
(2.5 mi) (Hilderbrand et al. 2007, p. 73). Thus, DFS in forest tracts
within 4 km of each other and not separated by physical barriers such
as rivers or cities were considered likely to be interbreeding; these
interbreeding groups of DFS were defined as subpopulations. The
analysis indicated that approximately 85 percent of DFS are found in
four large population groups which are narrowly separated and could
expand to become more connected. Each of these population groups
contains several times the minimum threshold of 130 squirrels needed
for a 95 percent probability of population persistence over 100 years;
and the rangewide population, estimated at between 17,000 and 20,000
animals, contains more than 100 times the minimum threshold for a
single population.
Effects of timber harvest. Two major studies of the effects of
timber harvest on DFS (Paglione 1996, entire; Bocetti and Pattee 2003,
entire) suggest that DFS are fairly tolerant of timber harvest,
although specific impacts depend on the size, location, and landscape
position of the harvest. Small clearcuts within a surrounding forest
showed relatively little impact on DFS, with individual squirrels
shifting their home ranges into adjacent habitat, whereas harvest of
more isolated forest peninsulas forced DFS to move greater distances.
In their long-term study, Bocetti and Pattee (2003, entire)
assessed the effects of 12- to 20-ha (30- to 50-ac) clearcuts within
which small islands of habitat were retained. The number of DFS found
pre- and post-harvest remained relatively unchanged, although the
number of gray squirrels dramatically declined. As the clearcuts
regenerated in the subsequent 10 years into young stands of trees, DFS
on the sites decreased to about half of their previous numbers, but
overall they maintained a continued presence, using both the islands
and adjacent areas of habitat (C. Bocetti, email 9/16/2009). These
findings lead to the general conclusion that the DFS can tolerate
timber harvests and can continue to occupy forested mosaics of mature
and regenerating stands. In addition, both studies of DFS responses to
timber harvest suggest that DFS have high site fidelity and tend to
shift home ranges rather than abandon a site in response to
disturbance.
Habitat availability. An inventory of mature forest suitable for
DFS, covering much of the squirrel's range, was recently completed
using Light Detection and Ranging (LiDAR) data provided by the State of
Maryland (USFWS 2012, appendix E). The ability to use remote sensing to
map DFS habitat has greatly improved our understanding of both DFS-
occupied habitat and, importantly, unoccupied habitat that is available
for potential DFS expansion. As of 2004, LiDAR mapping had identified
175,656 ha (434,056 ac) of mature forest in the eight Maryland counties
occupied by DFS (55 percent of all forest was considered mature) with
17 percent currently occupied and over 80 percent of mature forest
available for expansion (USFWS 2012, table 4).
Although these numbers and locations will change over time with
timber harvest and forest growth, this provides a good baseline
assessment of recent habitat patterns and indicates that mature forest
is well distributed and available. Mature forest is often found in
riparian zones where forests may be too wet to farm or log (USFWS 2012,
figure 8); these riparian forest corridors can provide connected
habitat for DFS dispersal and colonization of new areas. It is
important to note, however, that LiDAR mapping also showed large tracts
of mature forest distributed in upland areas throughout the Maryland
portion of the range. Given that most DFS populations occur in
Maryland, and, further, that unoccupied but suitable habitat is found
both along the coast and inland elsewhere on the Peninsula, we can
infer from this habitat inventory that there is ample unoccupied mature
forest to enable further expansion of the DFS rangewide population.
Habitat connectivity. Lookingbill et al. (2010, entire) conducted a
GIS analysis of the connectivity of forest patches on the Delmarva
Peninsula. This Delmarva Peninsula-wide study used satellite date to
identify forested areas, and evaluated connectivity between 400-ha
(175-ac) forest patches. Although the DFS is not a forest interior
obligate and does not require forest blocks this large, the Lookingbill
et al. (2010) model provides an interesting analysis of forest
connectivity between forest blocks that could hold larger populations.
Study results show high connectivity of forest blocks in the southern
Maryland portion of the squirrel's range, indicating few obstacles to
DFS dispersal throughout this area. The model treats the Choptank and
Tuckahoe Rivers as barriers to dispersal; although this may be accurate
for the wider sections of these rivers, it is less so for their upper
reaches, which are narrow and may freeze in the winter. Two major
forest corridors were identified for DFS dispersal out of Dorchester
County, Maryland, one of which is already occupied by DFS. In addition,
a third dispersal corridor not identified by the model is also DFS-
occupied. Observations of DFS movement through a wide range of
habitats, along with the results of this connectivity model and the map
of LiDAR-defined mature forests, indicate that there is sufficient
habitat availability and connectivity for further DFS range expansion.
Criterion 2: Benchmark populations are shown to be stable or
expanding based on at least five years of data. Criterion 2 was
originally intended to measure overall DFS population trends using at
least 5 years of monitoring data from seven benchmark populations (six
within the remaining natural range and the introduced Chincoteague
National Wildlife Refuge (NWR) population). Ultimately, a slightly
different set of eight benchmark sites was monitored and the resulting
data were analyzed (Dueser 1999, entire). Dueser (1999) concluded that
the benchmark sites were stable over a 5- to 7-year period, and
benchmark monitoring was ended.
Since the completion of benchmark monitoring, we have collected
additional data to better understand rangewide population trends. The
distribution data and two population evaluations described under
criterion 1 above are much better indicators of an expanding range and
DFS recovery within that range. Although DFS in isolated areas (such as
on small islands) are vulnerable to extirpation, the population data
for DFS in most of its occupied habitat and the discovery of additional
occupied forest tracts indicate that this recovery criterion has been
met.
Criterion 3: Ten translocated colonies are successfully established
throughout the historical range. This criterion requires that at least
10 new DFS colonies must be established (this may include
translocations initiated prior to issuance of the 1993 recovery plan)
within the squirrel's historical range and must show evidence of
presence for at least 5 to 8 years after release. The intent is to
demonstrate the ability of the DFS to colonize new sites, whether
naturally or through management.
Consequent to 16 translocation efforts, 11 colonies were
successfully established as shown by post-release trapping results
(Therres and Willey 2002, entire). More recent trapping and camera
surveys further indicate continued presence of these translocated
colonies for more than 20 years (USFWS 2012, table 1), and in many of
these areas, DFS have dispersed well beyond the initial release site.
The success rate for the DFS translocations (69 percent) is higher
than is typically found for similar translocation efforts for other
species. A
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study of 116 reintroductions found that only 26 percent were classified
as successful (Fischer and Lindenmayer 2000, p. 5), although the
success rate is generally higher for mammals and wild source
populations (Wolf et al. 1996, p. 1146). Although there were some
initial concerns about the genetic diversity of the translocated
populations, subsequent analysis indicated that their genetic diversity
was comparable to that of their source populations (Lance et al. 2003,
entire). Given the relative success of this conservation tool for DFS,
we conclude that this recovery criterion has been met.
Criterion 4: Five additional (post-1990) colonies are established
outside of the remaining natural range. Criterion 4 requires discovery
or establishment (from new translocations) of at least five new
colonies that extend the DFS's range beyond that known to be occupied
at the time of the 1993 recovery plan. This criterion addresses the
threat of range contraction and provides for additional redundancy of
populations as one component of long-term species viability.
By 2007, eight new populations had been identified that did not
result from translocations, (USFWS 2007, figure 2), expanding the range
toward the east. These consist of the Maryland DFS populations in
northeastern Dorchester County, southeastern Caroline County, the
Tuckahoe River corridor in Talbot County, northern Queen Anne's County,
the Centreville area of Queen Anne's County, eastern Talbot County,
northern Somerset County, and the Nanticoke Wildlife Management Area in
southwestern Sussex County, Delaware. The Sussex County population
represents the first population found in Delaware since the time of
listing that was not a result of a translocation.
Since the 2007 status review (USFWS 2007), additional occupied
forest has been discovered between some of these new populations, thus
improving their long-term likelihood of survival (USFWS 2012, figure
3). We therefore conclude that this recovery criterion has been met.
Criterion 5: Periodic monitoring shows that translocated
populations have persisted over the recovery period. Criterion 5
requires the continued presence of at least 80 percent of translocated
populations; in addition, at least 75 percent of these populations must
be stable or improving. All 11 translocated populations (100 percent)
that were successfully established have persisted over the full period
of recovery and have either grown in abundance on their release sites
or have expanded (or shifted) into new areas. Although their initial
success was documented solely by trapping techniques (Therres and
Willey 2002, entire), we have recently documented their presence by
trapping and/or camera surveys conducted between 2009 and 2011 (USFWS
2012, table 1). Overall, with the continued presence and growth of DFS
populations at the translocation sites, we conclude that this recovery
criterion has been met.
Criterion 6: Mechanisms that ensure perpetuation of suitable
habitat at a level sufficient to allow for desired distribution are in
place and implemented within all counties in which the species occurs.
This criterion requires that mechanisms be in place to ensure
perpetuation of sufficient suitable habitat. Several well-established
programs protect DFS habitat from development (Rural Legacy, Maryland
Environmental Trust, Maryland Agricultural Programs, etc.). These
programs, along with State and Federal ownership, protect an estimated
15,994 ha (39,524 ac), 29 percent, of DFS-occupied forest throughout
the squirrel's range (USFWS 2012, table 3). In addition, several State
laws and regulatory programs, including Maryland's Critical Area Law,
Forest Conservation Act, and wetlands laws, and Delaware's Agricultural
Land Protection Program and Forest Legacy Program will continue to
protect forest habitat (see USFWS 2012, appendix D). As further
described below, in Virginia and Delaware the DFS occurs primarily on
Federal and State land. The only Virginia population is a barrier
island population that was established on Chincoteague National
Wildlife Refuge (NWR) and is completely protected from residential
development or commercial timber harvest. We thus conclude that this
recovery criterion has been met.
Criterion 7: Mechanisms are in place and implemented to ensure
protection of new populations, to allow for expansion, and to provide
inter-population corridors to permit gene flow among populations. This
criterion requires sufficient habitat connectivity and protection to
permit gene flow among populations and allow for their expansion. As
discussed under criterion 1, LiDAR (remote sensing) data indicate that
mature forest blocks connected by riparian corridors are scattered
throughout the Delmarva Peninsula. An analysis of current forest
distribution using a J-walk model (Lookingbill et al. 2010, entire)
indicates these connected blocks constitute a good network of forest
across the Delmarva Peninsula to allow for dispersing DFS. For example,
the translocations on the southern part of the Delmarva Peninsula are
in an area of very large and well-connected tracts of forest, including
forest on public lands. In addition, there are protected forested
pathways connecting Dorchester County, where DFS are abundant, to
adjacent counties; DFS are known to use some of these corridors and
have found other corridors not identified by the J-walk model. Given
these opportunities for dispersal, and the fact that many of these
corridors are protected by State regulatory mechanisms (as discussed
under D. The Inadequacy of Existing Regulatory Mechanisms below), we
thus conclude this recovery criterion has been met.
Summary of Factors Affecting the Species
Section 4 of the Act and its implementing regulations (50 CFR part
424) set forth procedures for listing species, reclassifying species,
or removing species from listed status. ``Species'' is defined by the
Act as including any species or subspecies of fish or wildlife or
plants, and any distinct population segment of any species of
vertebrate fish or wildlife which interbreeds when mature (16 U.S.C.
1532(16)). Using the best available scientific and commercial data, a
species may be determined to be an endangered species or threatened
species because of any one or a combination 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. According to 50 CFR 424.11(d), we
may also delist a species on the same basis for any of the following
reasons: (1) The species is extinct, (2) the species has recovered and
is no longer endangered or threatened, and/or (3) the scientific data
used at the time the species was listed were in error.
A recovered species is one that no longer meets the Act's
definition of a threatened species or endangered species. Determining
whether a species is recovered requires consideration of the same five
categories of threats specified in section 4(a)(1) of the Act. For
species that are already listed as threatened species or endangered
species, we evaluate both the threats currently facing the species and
the threats that are reasonably likely to affect the species in the
foreseeable
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future following the delisting and the removal of the Act's
protections.
A species is an ``endangered species'' under the Act if it is in
danger of extinction throughout all or a significant portion of its
range. It is a ``threatened species'' if it is likely to become
endangered within the foreseeable future throughout all or a
significant portion of its range.
The Act does not define the term ``foreseeable future.'' For the
purposes of this proposed rule, we regard the foreseeable future as the
extent to which, given available data, we can reasonably anticipate
events or effects, or extrapolate threat trends, such that reliable
predictions can be made concerning the future status of the DFS. In
conducting this analysis, our general approach was to review past
threat trends and the observed DFS response, followed by a prediction
of future trends. We used a general timeframe of 40 years for examining
both past and future trends, noting that the timeframe for the future
trends is dependent on available data and can vary for specific
threats. We also took uncertainty into account. Because predictions
always have some uncertainty--and the further we try to look into the
future, the greater the uncertainty--a general period of 20 to 40 years
allowed for sufficiently reliable use of available data to inform our
projections.
In the following analysis, we first evaluate the status of the DFS
throughout all its range as indicated by the five-factor analysis. We
then consider whether the species is in danger of extinction or likely
to become so in any significant portion of its range (SPR).
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
This factor focuses on habitat changes caused by residential
development, sea level rise, and commercial timber harvest, as well as
the habitat-related effects on DFS viability, both rangewide and on DFS
subpopulations (see Recovery Criterion 1, Population Viability above).
There are 22 subpopulations, representing groups of interbreeding DFS
(Hilderbrand et al. 2007, p. 73), within the subspecies' current range
(USFWS 2012, figure 5, table 7). While they occur in three States, the
only Virginia population is a barrier island population that was
established on Chincoteague National Wildlife Refuge (NWR) and is
completely protected from residential development or commercial timber
harvest. We do not, therefore, analyze development or timber harvest
for the Virginia portions of the Delmarva Peninsula where DFS do not
occur; however, the impact of sea level rise on this population is
addressed.
Potential habitat loss due to development: Past development trends.
The Delmarva Peninsula is basically a rural landscape, but the human
population has increased since the DFS was listed. For instance, in the
eight Maryland counties that harbor DFS, the human population increased
from approximately 200,000 to 300,000 between 1970 and 2000 (http://
planning.maryland.gov/msdc/popproj/TOTPOPPROJ08.pdf).
Consequently, acres of developed land increased from 3 percent of the
landscape in 1973 to 8 percent in 2002 by one estimate (Maryland
Department of Planning 2008, pp. 22-23). Another land-use
classification scheme showed an increase to 11 percent developed in
2002 and 12 percent in 2010 (http://planning.maryland.gov/OurWork/landuse.shtml). Despite these increases and several areas that are
continuing to grow, the majority of the Delmarva Peninsula is rural
with approximately 45 percent agricultural land and 35 percent forest
(USFWS 2012, table 2).
During the same time period, a variety of State laws and programs
were put in place to counteract the rate of development (USFWS 2012,
appendix D). These include the Maryland Forest Conservation Act, which
requires offsetting forest clearing for development with forest
protection or afforestation, and the Maryland Critical Area Law, which
now requires that the land within 200 feet of tidal waters cannot be
developed and that the forest in this zone must be maintained.
In addition, three State programs that protect private land from
development on a voluntary basis have resulted in conservation of
79,066 ha (195,377 ac) of private land in the DFS's Maryland range
(USFWS 2012, table 3). These programs include the Maryland
Environmental Trust, the Maryland Agricultural Land Protection Fund,
and the Maryland Rural Legacy Program. Together, these programs
protected about 3,642 ha/year (9,000 ac/year) between 2000 and 2008
(USFWS 2012, chart 4), which is triple the rate of development between
1973 and 2002 (Maryland Department of Planning 2008, pp. 22-23).
Overall, approximately 30 percent of DFS-occupied forest is
protected from development, and these lands are widely distributed
across its range (USFWS 2012, table 5). Additional acres of protected
forest occur outside the current range of the DFS and provide areas for
further expansion (USFWS 2012, figure 7). The 15,995 ha (39,524 ac) of
occupied forest that is protected from development could contain a DFS
population that is about 45 times the size of the MVP determined
through the PVA (Hilderbrand et al. 2007, entire). Nonetheless, 70
percent of DFS-occupied forest occurs on private land that is legally
unprotected from development; thus, future losses from development are
likely.
Potential habitat loss due to development: Future development
trends. The Maryland Department of Planning (http://
planning.maryland.gov/msdc/popproj/TOTPOPPROJ08.pdf) predicts
that by 2030 the human population in the eight Maryland counties where
DFS occur will reach 400,000 (in 2000, the human population was roughly
300,000). Further, under the worst-case scenario, where Smart Growth
policies are not implemented and sprawl is maximized, the amount of
developed land in the eight Maryland counties could encompass 14
percent of the landscape by 2030. The greatest growth is expected to
occur in the vicinity of Salisbury and Ocean City, which are outside
the current range of the DFS. However, sprawl development in Queen
Anne's County and the area around Easton is also identified in the
report and would occur within the northern portion of the squirrel's
range (the ``northern portion'' is commonly understood to include Kent,
Queen Anne's, Talbot, and Caroline Counties in Maryland, while the
``southern portion'' is understood to include the Sussex County DFS
population in Delaware, the southern four counties in Maryland, and the
DFS population in Accomack County, Virginia).
We assessed the potential threat of DFS habitat loss stemming from
future development by overlaying the acres of existing occupied forest
with areas projected to be lost to development, including: (1) Smart
Growth areas (excluding the acres that are protected by easement), (2)
areas where development projects are already planned, and (3) areas
that are projected to be lost by 2030 if Smart Growth policies are not
implemented (USFWS 2012, figure 11).
Overall, 3 percent (2,283 ha or 5,643 ac) of the forest area
currently occupied by DFS is anticipated to be lost to development by
2030. The reason for this relatively low level of loss is that most of
the future development on the Delmarva Peninsula is projected to occur
outside the current range of the DFS (e.g., Kent Island, Salisbury, and
Ocean City). Development within the current range is expected to affect
two
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small, isolated DFS subpopulations where extirpation already appears
likely. Although loss of these two isolated populations is likely,
together they constitute less than 0.5 percent of the total MVPs, and
their loss will, therefore, have a negligible effect on the extinction
risk for the rangewide DFS population. While we do not currently have
additional projections of development past 2030, we expect most future
development on the Delmarva Peninsula beyond this time will continue to
occur outside the current range of the DFS. Additionally, as described
below, with anticipated continued expansion of DFS populations and
State laws providing protection of DFS forest habitat, we expect any
future loss of habitat due to development to have a negligible effect
on the extinction risk for the rangewide DFS population.
The discovery of additional occupied forest areas may offset this
projected loss of occupied forest, resulting in little change to the
overall area of the distribution. In the past 10 years, discovery of
new occupied forest has occurred at the rate of 763 ha/year (1,887 ac/
year). We might expect the rate of discovery of new occupied forest to
diminish in the future, but even if we discover new occupied forest at
half that rate, or 382 ha/year (944 ac/year), we will have offset
anticipated losses from development in 6 years.
In summary, in the past 40 years, development has eliminated some
forested habitat, but the DFS range has expanded despite these losses.
Although past increases in DFS occurrences are attributable in part to
the cessation of hunting and DFS translocations, the number and
distribution of naturally occupied woodlands have also increased. The
discovery of new occupied forest is anticipated to exceed anticipated
losses of forest from future development. Protection of DFS-occupied
forest from future development occurs through several State
conservation easement programs, and 30 percent of the occupied habitat
is permanently protected from development through easements or public
ownership. State laws are now more protective of DFS forest habitat
than they were in the past, and these protections are likely to
continue into the future, resulting in conservation of additional
forest habitat. Given the projection that future losses are likely to
be relatively small, combined with the availability of ample unoccupied
habitat for DFS to move into, the loss of occupied habitat due to
development does not pose an extinction risk for the DFS.
Potential loss of forest habitat from sea level rise. The Delmarva
Peninsula is a low-lying landform, and increases in the relative sea
level of the Chesapeake Bay can flood and kill shoreline forests that
constitute DFS habitat. Although these dynamic processes have been
occurring for centuries, relative sea level rise has occurred at an
accelerating rate (Sallenger et al. 2012,entire; Boesch et al. 2013,
entire). The DFS is not a coastal species in that it does not depend on
coastal habitats specifically, and this moderates its vulnerability to
sea level rise compared to marsh-dependent species. In addition, it
uses a wide range of mature forest types across the Peninsula and a GIS
analysis indicates over 80 percent of the current range would remain,
even after inundation by 0.61 m (2 ft) of water. However, the squirrel
does occur in forest blocks along the edge of the Chesapeake Bay where
sea level rise has occurred in the past and will continue into the
future.
Sea level rise in the past. The forces of land subsidence and sea
level rise have resulted in a long history of island loss and formation
in the Chesapeake Bay. In the last century, these forces combined to
produce a relative sea level rise in the Chesapeake Bay region of about
3.4 millimeters (mm)/year (0.134 inches (in)/year) (National Oceanic
and Atmospheric Administration 2006, p. 4), or approximately 0.3 m/100
years (1 ft/100 years) (National Wildlife Federation 2008, p. 2).
Loss of some forest stands in southern Dorchester County is already
apparent where shoreline timber stands at the lowest elevations have
been killed by saltwater from recent hurricanes. Although we cannot
precisely quantify how much occupied habitat has been lost in the past
40 years, the LiDAR analysis of forest height and canopy cover has
identified at least 68 ha (170 ac) of forest at the edge of coastal
marshes that are now standing dead trees.
Hurricanes are part of the process that results in loss of forest
from saltwater as sea levels rise. Saltwater moves further into
forested areas during associated storm surges, which can kill or weaken
trees. Hurricanes have always been part of the weather in this area and
there is no evidence that hurricanes per se pose a problem for DFS.
Even during super-storm Sandy in October 2012, cameras set out to
monitor DFS in woods near the Atlantic coast recorded DFS onsite after
the hurricane passed. While there is always the possibility that
hurricanes or any storm can topple trees used by DFS, the major effect
is the additional push of saltwater into more upland areas, killing
coastal forest trees.
Future effects of sea level rise and climate change. Sea level rise
in the Chesapeake Bay is certain to continue in the future, and the
rate of change is likely to be even higher than in the past (National
Wildlife Federation 2008, pp. 16-17; Sallenger et al. 2012, entire;
Boesch et al. 2013, entire). While the precise rate of change may be
debated, we have chosen to evaluate a 0.61-m (2-ft) inundation scenario
to determine the extent of occupied forest that may be lost through the
combined effects of sea level rise and subsidence (i.e., relative sea
level rise) despite uncertainty about when this might occur. A sea
level rise of this magnitude (0.61 m or 2 ft) is predicted to occur by
about 2050 using the high or extreme scenario and by 2100 using the low
scenario (Boesch et al. 2013, p. 15).
To determine the acres of DFS-occupied forest that might be lost
due to sea level rise, we conducted a GIS analysis of DFS-occupied
habitat overlaid by an inundation level of 0.61 m (2 ft) on the
landscape by 2050 (USFWS 2012, p.31). Although we considered this to be
the worst-case scenario for the next 40 years (Boesch et al. 2013, p.
15), it may be a more likely scenario over a 60- to 100-year timeframe
(Boesch et al. 2013, p. 15; National Wildlife Federation 2008, p. 16).
Our GIS analysis indicated that the most severe effects of sea
level rise on DFS by 2050 will be seen in the southwestern portion of
Dorchester County, Maryland (USFWS 2012, figure 12). Here, the
landscape is a convoluted shoreline bounding a mix of marsh and forest.
With 0.61 m (2 ft) of inundation, the marsh would be submerged, islands
of forest would gradually become smaller, and eventually the forest is
likely to be killed by saltwater intrusion. Using this inundation
scenario, 9,332 ha (23,060 ac) of currently occupied forest would
either be lost or remain only on isolated islands (USFWS 2012, figure
12). In addition, 4,409 ha (10,897 ac) of habitat along the remaining
southern edge of the county would eventually deteriorate, causing DFS
to move inland. Noting that the ability of DFS to move into connected
habitat likely reduces the effects on this subspecies of forest losses
at the coastal marsh fringe, we nonetheless consider this as habitat
loss. Remaining losses are scattered in small areas throughout the
range, including some losses at the Chincoteague population (USFWS
2012, figure 12).
The predicted habitat losses from sea level rise are thus greatest
in
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southwestern Dorchester County, but even if these losses were to occur
immediately, the area's remaining 23,632 ha (58,398 ac) of occupied
habitat would continue to support a highly abundant DFS population with
a negligible risk of extinction. Moreover, the habitat in the
northeastern portion of this area is connected to existing occupied
forest farther inland (USFWS 2012, figure 9). We anticipate that DFS
will move into a large tract of State-owned forest that will mature
into suitable DFS habitat within the next 10 years. Analysis of forest
connectivity indicates that this area either already allows or will
soon allow for DFS expansion, and it connects the Dorchester DFS
subpopulation to forest tracts in Caroline and Sussex Counties (USFWS
2012, figure 10). Although sea level rise may cause streams and rivers
to widen and pose more of a barrier than they currently do, forested
paths will still be available to provide DFS access to habitat in the
inland portions of Dorchester County. Thus, losses in the southwestern
portion of the county could be tolerated, but they will likely be
mediated by a population shift to the large interior portions of the
county.
Given our current understanding of DFS habitat use, dispersal, and
population dynamics, the expected DFS response to deterioration of
coastal woodlands from sea level rise is the gradual movement of some
DFS to more inland areas. The DFS is known to travel across areas of
marsh and can move at least 40 to 50 m (131 to 164 ft) across marshland
between forested islands and may also move across frozen marsh in the
winter. We acknowledge that even with the squirrel's ability to move,
some isolation and loss of individuals are likely to occur, and a
portion of the squirrel's habitat in southwestern Dorchester County
will become degraded or lost. Nonetheless, because of the large size of
the Dorchester subpopulation that would remain, as well as the presence
of currently unoccupied but suitable habitat for the DFS, we conclude
that habitat loss due to sea level rise will not be a limiting factor
to the future viability of this subspecies.
The 0.61-m (2-ft) inundation scenario does not play out the same in
other parts of the range. In the series of small peninsulas in
northwestern Dorchester County called the ``neck region,'' this
scenario results in shrinkage of available habitat but does not create
islands and leaves habitat for DFS to move into (USFWS 2012, figure
12). This is also the case in other portions of the squirrel's range
near the Chesapeake Bay and the Atlantic Coast. Some additional small
areas of occupied habitat may be lost, but the gradual loss can be
accommodated by shifts in DFS home ranges to adjacent but currently
unoccupied habitat.
The most coastal population of DFS is a translocated population
introduced in 1968 to Chincoteague NWR, a barrier island in Virginia
that could be severely affected by sea level rise (National Wildlife
Federation 2008, p. 69). The refuge's draft Comprehensive Conservation
Plan (draft available at: http://www.fws.gov/nwrs/threecolumn.aspx?id=2147550165) addresses this issue, and the refuge
may consider future land acquisitions on the Delmarva Peninsula
mainland. Chincoteague NWR will continue to manage for DFS into the
future whether or not the species remains listed. In addition,
translocations of DFS to areas outside refuge boundaries at some point
in the future are possible.
It is not clear how climate change effects may alter the nature of
the forests of the Delmarva Peninsula. If climate change effects result
in warmer conditions in the long term, the loblolly pine-dominated
forests on the southern half of the Delmarva Peninsula may become even
more predominant. However, since DFS occur in forests that range from
all hardwoods to all pines and prefer a good mix of hardwoods and pines
with diverse tree species, shifts in the species composition of these
forests are not likely to become a significant threat for the squirrel.
In summary, DFS distribution has increased in the past 40 years
even with some sea level rise occurring (at a rate of approximately 0.3
m (1 ft) in 100 years). In the next 40 to 50 years, under a worst-case
scenario of a 0.61-m (2-ft) rise in sea level, we predict some
deterioration of forests in certain areas along the Chesapeake Bay and
the Atlantic Coast (USFWS 2012, figure 12), but we also anticipate
population expansion and shifts in DFS home ranges into suitable but
currently unoccupied habitat that is available in the interior of the
Delmarva Peninsula. Although some concern has been expressed about the
likelihood of such expansion (CBD 2013), the analysis of habitat
suitability, connectivity, and the range expansion documented in the
last 15 years provides a strong basis for this expectation. Thus,
available data indicate that the loss of habitat due to sea level rise
does not pose an extinction risk to the DFS.
Combined effects of development and sea level rise. Although no
individual threat under Factor A threatens this species with extinction
now or in the foreseeable future, we examined the combined effects of
the most pervasive stressors--future habitat loss from development and
sea level rise--using a GIS analysis (USFWS 2012; figure 5, table 7).
Beginning with the total area of forest occupied in 2010, we
subtracted all possible projected losses from development and sea level
rise. We then added a conservative estimate of the average acres of
occupied forest that have been discovered annually for the last 10
years. We considered this for the entire range and for 22
subpopulations within the range. We also estimated the number of MVPs
(calculated as a population containing 65 females, or 130 animals
total) in each subpopulation (USFWS 2012, pp. 41-42) to gauge the
extinction risk of each subpopulation. This enabled a spatial analysis
of how the impacts of both development and sea level rise might
interact.
As of 2010, there were 54,429 ha (134,496 ac) of DFS-occupied
habitat distributed among 22 subpopulations, with an estimated DFS
population approximately 171 times the size of an MVP (USFWS 2012,
table 7). Apart from two small, isolated subpopulations that are likely
to become extirpated because of both their size and location, the
majority of the 22 subpopulations have some likelihood of remaining at
or above current population levels given that they are either large
enough to contain a population comparable to one or more MVPs or, if
smaller, they are located close to other subpopulations (USFWS 2012,
table 7, figure 5).
If we subtract the habitat that might be lost from development and
sea level rise and do not count any expected discoveries of additional
occupied habitat, we still retain 37,795 ha (93,393 ac) of occupied
forest and a rangewide population of 17,000 to 20,000 DFS, that is, 120
times the MVP size. Ninety-five percent of DFS are found in the 11
largest subpopulations, all of which are considered likely to stay at
or above current population levels, because they contain at least one
MVP after all losses. With expected discovery of at least some
additional occupied forest, it is more likely that the total DFS-
occupied area will increase and that subpopulations are likely to
become more connected and even more likely to remain at or above
current levels into the foreseeable future. Thus, even with the
cumulative loss of habitat from development and sea level rise, the
factors analyzed do not endanger or threaten this species with
extinction now or in the foreseeable future.
Loss of mature forest from timber harvest. Unlike development and
sea
[[Page 56697]]
level rise, timber harvest does not result in permanent loss of
habitat. A timber harvest is followed by growth of a young forest,
resulting in a landscape mosaic of mature and regenerating forest
stands. DFS are resilient to timber harvests when there is adjacent
habitat they can move into (Paglione 1996 pp. 69-73; Bocetti and Pattee
2003, entire). The major threats that could be posed by timber harvests
are, therefore, (1) the prevalence of short-rotation timber harvests,
where trees are harvested before they mature enough to become DFS
habitat; and (2) harvest rates that exceed growth rates and result in a
continual decline of mature forest.
Potential threat from short-rotation pine forestry. Short-rotation
pine forestry involves harvesting trees at approximately 25 years of
age for pulp and other fiber products. Since it takes approximately 40
years to produce suitable DFS habitat, forests harvested at 25 years of
age never become suitable for DFS breeding. In the past, there were two
large corporations managing for short-rotation pine on the Delmarva
Peninsula. However, these industries have effectively left the Delmarva
Peninsula, and in 1999 the State of Maryland acquired 23,471 ha (58,000
ac) of land to be managed for sustainable sawtimber production and
wildlife values. These lands, collectively administered as the
Chesapeake Forest Lands, are scattered parcels throughout the southern
four Maryland counties (USFWS 2012, figure 13). In addition, 4,202 ha
(10,384 ac) of forest land previously owned and managed for short-
rotation pine are now owned by the State of Delaware. All these lands,
on which short-rotations formerly precluded DFS habitat, will now be
protected from development and managed for sustainable sawtimber
harvest and wildlife habitat objectives. With compatible management,
these forests will provide suitable habitat for DFS into the
foreseeable future.
Most of this land is currently in early stages of forest
succession; 48 percent of Maryland Chesapeake Forest Lands in 2013 were
less than 25 years old and about 30 percent were at least 41 years old
(Maryland DNR 2013, p. 43). Within 10 years, however, most of the
forested areas will be over 26 years of age and there will be more than
30 percent of the stands over 41 years and potentially suitable for DFS
(Maryland DNR 2013, p. 43). Moreover, DFS management has been
integrated into the Sustainable Forest Management Plan for Chesapeake
Forest Lands (Maryland DNR 2013, pp. 92-96), which identifies a total
of 17,618 ha (43,535 ac) as DFS Core Areas and DFS Future Core Areas
where management is for 60- to 80-year rotations. According to the
management plan, at least 50 percent of the DFS Core Areas must be
maintained in suitable DFS habitat at any one time, with a management
emphasis on mature mixed pine/hardwood stands (Maryland DNR 2013, p.
94). Thus, while most of the Chesapeake forest lands are currently
unoccupied by DFS and are too young to provide breeding habitat, these
areas are protected from development and will provide suitable DFS
habitat in the near future. Overall, the Chesapeake Forest Lands
represent a future of protected forest areas managed for sawtimber
where DFS can survive and grow in numbers. This land acquisition
substantially removes the threat posed by short-rotation pine
management and provides a positive outlook for future habitat for the
DFS on the lower portion of the Delmarva Peninsula.
Timber harvest across the landscape in the past. The 2007 review
(USFWS 2007, pp. 17-20) evaluated the threat from timber harvest using
the U.S. Forest Service's Forest Inventory and Analysis data (Frieswyk
2001, entire) in conjunction with a database of sediment-and-erosion-
control permits obtained from the counties. Although these data were
the best available at the time, there was some concern about the
possibility of underestimating harvest rates based on the number of
permits issued. Conversely, this analysis approach also led to a
concern about overestimating harvest rates, because there was some
evidence that individuals may obtain the permits in anticipation of
good harvesting conditions but then not actually conduct the harvest.
This particularly appeared to be the case in Dorchester County.
Consequently, since the 2007 review we have looked at corollary means
of understanding timber harvest rates (e.g., direct reports from State
foresters in each county and LiDAR analysis), while acknowledging that
each technique has some potential biases and results are not
comparable. Due to the latter issue of comparability, the 2012 status
review's (USFWS 2012, table 6) estimates of acres harvested in each
county used the sediment-and-erosion-control permits simply because
these data are collected in the same way over time. The exception to
this is the estimate for Sussex County, Delaware, which is considered
to represent actual acres harvested on the ground, because permits are
not granted until immediately before the harvest.
The average annual harvest in the most recent years preceding this
review is substantially less than in previous years, (generally prior
to 2005) according to the permit database (USFWS 2012, table 6). In the
four southern Maryland counties, the average annual harvest has dropped
from approximately 1,050 ha (2,594 ac) prior to 2005 to approximately
303 ha (749 ac) since 2005. The average size of the harvest in these
counties has also decreased from an average of 22 ha (54 ac) to an
average of 15 ha (36 ac). In the northern four counties in Maryland,
annual harvest was low prior to 2005 and stayed about the same in more
recent years, with recent estimates averaging 235 ha (582 ac). The size
of harvests was also about the same and averaged 14 to 15 ha (35 to 38
ac). Given that most forest harvest occurs in the southern counties,
the result is a substantial decrease in total acres harvested since
2005.
This is also the case in Delaware, where we find the permit
database to be very accurate. In Sussex County, the annual harvest rate
in the last 4 years was half of what was generally harvested between
1998 and 2005. Not only has the annual harvest acreage declined, but so
has the size of individual harvest areas. In the mid- to late 1990s,
the typical size of timber harvests ranged from 12.1 to 28.3 ha (30 to
70 ac), while over the past 5 years the average size of timber harvests
ranges from 8.9 to 19.4 ha (22 to 48 ac).
Among other reasons for this overall reduction in timber harvests,
economic events have resulted in the closure of several sawmills on the
Delmarva Peninsula; this was beginning to happen even before the 2008
recession. The market for timber has declined dramatically, and the
loss of sawmills is both a cause and a reaction to lower demand. Prices
for timber remain very low, and the incentives to harvest are thus low.
As discussed below, additional factors suggest that reduced harvest
levels are likely to continue in the future.
Future Threats Posed by Timber Harvest. Although it is very
difficult to predict future market forces, several trends suggest
future timber harvests might remain smaller in size and occur less
frequently. An assessment of forests in the Chesapeake Bay area
(Sprague et al. 2006, pp. 22-24) refers to trends in fragmentation and
parcelization of forests in the Chesapeake Bay region. Parcelization is
the subdivision of large blocks of land into multiple ownerships. As
forest lands are subdivided, landowners tend to change from management
of their woodlands for timber to management for aesthetics and wildlife
values. The National Woodland Owner Survey conducted by the U.S. Forest
Service found that in Maryland
[[Page 56698]]
45 percent of the woodland owners own less than 20 ha (50 ac) of woods
(U.S. Department of Agriculture, 2012), whereas most clearcuts in the
past were 9 to 20 ha (22 to 50 ac) in size. Thus, almost half of the
woodland owners do not own enough woodland to accommodate harvests the
size of an average clearcut without losing nearly all of their woods.
In addition, these owners are not likely to be managing for timber
as a source of income. This ownership pattern also reflects the
``gentrification'' of the eastern shore of Maryland, with landowners
becoming less likely to be farmers or foresters and more likely to be
commuters or retirees that do not earn their livings from the natural
resources on their properties. The proportion of the population in this
area that is greater than 65 years of age has been increasing in the
past and is projected to increase in the future
(www.mpd.md.state.md.us./msdc/county). Although these landowners may
harvest small portions of their woods, they are likely to retain some
portions as well. This continued parcelization and gentrification is
expected to reduce the number of landowners managing for timber values,
reduce the size of timber harvests, and result in an overall reduction
in the total acres harvested. This trend is already apparent in the
reduced average size of timber harvests indicated by the sediment-and-
erosion control-permit databases discussed above.
In summary, the threat posed by short-rotation pine timber harvests
has largely been eliminated by the transfer of 23,472 ha (58,000 ac) to
the State of Maryland and 4,202 ha (10,384 ac) to the State of Delaware
to be managed for sawtimber and wildlife habitat. Additionally, the
timber harvest rates on private lands across the eight Maryland
counties have declined dramatically in the past several years. Even if
harvest rates were to increase in the future and approach the levels
reported in the 2007 status review (USFWS 2007, pp. 19-20), the impacts
would not be significant, because DFS are known to have expanded their
range even at that level of harvest (i.e., under past harvest rates,
approximately 55 percent of the forest in the eight Maryland counties
was mature forest either occupied by or potentially suitable for DFS
(USFWS 2012, table 4)). The Delmarva Peninsula-wide forest mapping also
indicates that ample, well-connected habitat is available for DFS
expansion, even under past harvest rates. Nonetheless, future timber
harvest on the shore is likely to be more limited than it has been in
the past because of changes in the timber market and landownership
patterns. And, importantly, the transfer of 27,674 ha (68,317 ac) of
timber lands with sustainable management provisions to Maryland and
Delaware will provide significant long-term conservation benefits for
the DFS. These land transfers, in conjunction with available data on
harvest rates across the range of the squirrel, suggest that timber
harvest does not pose an extinction risk for the DFS.
Factor A summary. The current range of the DFS spans the northern
and southern portions of the Delmarva Peninsula, from coastal areas to
the interior of the Delmarva Peninsula. DFS inhabit a wide range of
forest types from hardwood-dominated to pine-dominated forests and from
wetland to upland forests, suggesting that the DFS would continue to
remain at or above viable population levels under a variety of
conditions. The wide distribution provides redundancy of occupied
forest across the landscape, which also reduces extinction risk. Timber
harvest rates in the past have not prevented population expansion, and
the harvest rates are likely to be even lower in the future. We expect
the rangewide DFS population to remain viable and to continue to occupy
the full complement of landscapes and forest types on the Delmarva
Peninsula. We conclude that habitat losses may occur in some areas from
residential development or sea-level rise, but we expect the DFS
population to remain at or above recovered levels, and, moreover, we do
not expect such habitat losses to prevent overall expansion of the
range in the future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Overhunting has been posited as a factor in the original decline of
this species. Squirrel hunting was common in the early and middle
decades of the 20th century, and, given the DFS's larger size and
tendency to be on the ground, they may have been preferred game over
gray squirrels. Squirrel hunting was also a common way for young
hunters to gain experience. Hunting of DFS in small, isolated woodlots
or narrow riparian corridors could have resulted in local extirpations,
and Taylor (1976, p. 51) noted that DFS remained present on large
agricultural estates where hunting was not allowed, suggesting that
these areas may have provided a network of refugia for DFS as the
subspecies became extirpated elsewhere.
Hunting in the Past 40 Years. Hunting of DFS was banned through
State regulations in 1972. Removal of hunting pressure, combined with
other factors, may have allowed renewed population growth and expansion
of the squirrel's range to its current extent. Coincidentally, squirrel
hunting has declined in popularity in recent decades (replaced largely
by deer hunting). Nationwide, squirrel hunting declined by 41 percent
between 1991 and 2001, along with an overall decline in the number of
citizens hunting (USFWS 2001, p. 5). Across Maryland, the number of
hunters pursuing gray squirrels declined by almost half between 2000
and 2005, from about 19,000 to 10,000 hunters, while the number of
hunters pursuing western fox squirrels (Sciurus niger rufiventor) in
western Maryland dropped from about 3,000 to 1,800
(www.dnr.state.md.us/wildlife/gpar/gpfurtable1.asp). Although
some hunters may mistake DFS for gray squirrels (despite educational
efforts to help hunters differentiate between the two), this is likely
a rare situation that has not prevented the DFS from expanding over the
last 40 years.
Hunting in the Future. Discussions with our State partners suggest
that DFS management after delisting would be conducted very carefully
and that a hunting season would not be initiated in the immediate
future. We recognize that a very restricted hunt could be conducted at
sites where DFS are abundant without causing a population decline, and
that State management agencies have the capability to implement careful
hunting restrictions and population management; for instance, the
reopening of the black bear (Ursus americanus) hunt in Maryland is a
good example of a carefully and successfully managed hunt (Maryland
Department of Natural Resources 2012, entire).
We nonetheless foresee only limited public interest in reinitiating
a DFS hunt, coupled with strong public attitudes against hunting DFS.
Public sentiment toward hunting in general has changed, with hunting
for food, management of game populations, and animal population control
considered acceptable, whereas hunting strictly for recreation is
considered less acceptable (Duda and Jones 2008, p. 183). Given public
attitudes, the declining interest in squirrel hunting, and the
restrictions that we expect would be imposed on a renewed hunting
program, hunting is highly unlikely to pose an extinction risk to the
DFS in the foreseeable future.
C. Disease or Predation
Disease. Reports of disease in DFS are uncommon. Although other
subspecies
[[Page 56699]]
of eastern fox squirrels are known to carry diseases such as mange and
rabies, there is no documentation of these diseases in DFS, and there
is no evidence or suspicion of disease-related declines in any local
population (USFWS 2012, pp. 37-38).
Despite the lack of apparent vulnerability to date, however, the
recent advent of white-nose syndrome affecting bats (Blehert et al.
2009, entire) and chytrid fungus affecting amphibians (Daszak et al.
1999, entire) demonstrates the uncertainty surrounding novel disease
events. The life-history traits of DFS nonetheless make them less
susceptible to these types of epizootics. First, DFS do not congregate
in large numbers (such as bats in hibernacula), where disease can
easily spread through a population. Second, early records describe the
DFS as patchily distributed across its range (Taylor 1976, p. 7), and
this continues to be the case; this patchy distribution makes it more
difficult for disease to spread through the squirrel's range. Finally,
DFS are not migratory or in an environment (as with aquatic species)
where pathogens can readily disperse. There currently is no evidence of
disease-related declines or any indication that DFS are particularly
susceptibility to disease outbreaks, and we conclude that disease is
neither a current nor future extinction risk for this subspecies.
Predation. Predators of DFS include the red fox (Vulpes vulpes),
gray fox (Urocyon cinereoargenteus), red-tailed hawk (Buteo
jamaicensis), bald eagle (Haliaeetus leucocephalus), and possibly
domestic pets and feral animals (e.g., cats and dogs). Owls are
probably not major predators, as camera surveys have found that DFS
activity patterns rarely include dawn or evening hours, although the
gray squirrel is active at these times. Morris (2006, pp. 35, 77) found
that the majority of camera detections occurred between 8 a.m. and 5
p.m. with two peaks in activity at mid-morning and mid-afternoon.
Changes in predator numbers may cause some fluctuations in DFS
numbers at a site (e.g., a DFS population may decline when red fox
populations increase), but these types of events are sporadic and
localized. Likewise, bald eagle numbers have dramatically increased in
the Chesapeake Bay region over the past 40 years, but although they
have been known to take DFS, they still prey primarily on fish. While
feral dogs and cats may occasionally take DFS, such predation is not a
rangewide threat. The DFS population has increased over the last 40
years despite ongoing predation, and we conclude that predation at
these levels is not a current or future extinction risk for this
subspecies.
D. The Inadequacy of Existing Regulatory Mechanisms
Several laws established in Maryland over the past 40 years provide
substantial protections for DFS habitat (USFWS 2012, appendix D). The
Maryland Critical Areas Act of 1984 designates all areas within 304.8 m
(1,000 ft) of high tide as Critical Areas and originally prohibited
development and forest clearing within 30.48 m (100 ft) of streams and
the Chesapeake Bay. This law was amended in the spring of 2008 to
increase this ``no-development or forest clearing buffer'' to 60.96 m
(200 ft). These areas serve as corridors for DFS and as breeding
habitat. The Maryland Forest Conservation Act of 1991 requires that,
when a forested area is cleared and converted to other land use, other
portions of the forest must be placed in an easement that will preclude
development in perpetuity or, alternatively, other areas must be
replanted to offset these losses. In addition, the State-implemented
portions of the Clean Water Act protect the many forested wetlands
where DFS occur.
Several State programs encourage voluntary conservation easements
that protect lands from development; the Maryland Agricultural Land
Protection Fund (MALPF), Maryland Environmental Trust (MET), and Rural
Legacy Program collectively protected 3,624.4 ha (8,956 ac) per year
from 2000 to 2008 in the eight Maryland counties where DFS occur. These
programs protect 79,066 ha (195,377 ac) of private land in Maryland and
similar programs in Delaware protect an additional 12,677 ha (31, 327
ac) in Sussex County (USFWS 2012, table 3).
Although in Delaware and Virginia the DFS occurs primarily on
Federal and State land, private lands are protected for continued
expansion. For example, Delaware also has an Agricultural Land
Protection Program and a Forest Legacy Program, and, although these
programs started later than in Maryland, they have already protected
more than 12,677 ha (31, 327 ac) in Sussex County. The Virginia
population is completely protected on Chincoteague National Wildlife
Refuge, a coastal island, and expansion in Virginia would require
additional translocations. However, the State owns lands that would be
suitable for future translocations, and there are private lands
protected by land trusts as well.
Overall, many State laws and programs that protect DFS and their
habitat have been enacted or strengthened in the last 40 years, and it
is likely that this State protection will continue. Currently, these
regulatory mechanisms, together with other factors that address
population and habitat trends, have reduced the threats identified for
the DFS. We thus conclude that the inadequacy of existing regulatory
mechanisms does not pose an extinction risk to the DFS.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
The following factors have been identified as posing potential
extinction risks to the DFS. The level of risk posed by each factor is
assessed below.
Forest pest infestations. Under Factor A, we evaluated habitat loss
as a result of development, sea level rise, and timber harvest.
However, additional factors can affect forest health and its ability to
provide suitable habitat for DFS, including forest pest infestations.
Gypsy moth (Lymantria dispar) and southern pine bark beetle
(Dendroctonus frontalis) outbreaks can decimate mature forest stands,
although the affected stands will eventually regenerate. However,
monitoring and spraying for gypsy moth control appears to have reduced
this threat within the current range of DFS; infestations in the last
several years have diminished in acreage and occurred in other parts of
the State (Maryland Department of Agriculture, Forest Health Highlights
2007, 2008, 2009, entire).
Pine bark beetle infestation necessitated salvage cuts for a total
of 809.37 ha (2,000 ac) scattered across the southern counties in the
early 1990s, but monitoring and control efforts appear to have reduced
this threat as well.
Overall, an analysis of forest-pest risk across counties in the
Chesapeake Bay watershed found that most areas on the Eastern Shore
where DFS occur have relatively low risk for insect infestations, with
most having 3.8 to 10 percent of their area considered to be at risk
(Sprague et al. 2006, p. 87). Although emergence of new forest pests is
to be expected, the Maryland Department of Agriculture has a Forest
Health Monitoring Program that conducts surveys to map and report
forest-pest problems (Maryland Department of Agriculture, Forest Pest
Management, 2012, entire). Forest-pest outbreaks are likely to recur
and may increase if climate warms as projected; however, this threat
appears to be localized and sporadic and, with existing programs to
monitor and treat forest pest outbreaks, we conclude that it is not an
extinction risk factor.
[[Page 56700]]
Vehicle strikes. Vehicle strikes are a relatively common source of
DFS mortality. Similar to other species, the probability of DFS being
hit by vehicles is dependent on the density of DFS in the area and the
proximity of the road to habitat. The frequency of road kills has been
shown to reflect general patterns of abundance of many species over
large geographic areas or time periods (McCaffery 1973, entire; Earle
and Kramm 1982, entire; Gehrt 2002, entire; MacPherson et al. 2011,
entire).
Vehicle strikes of DFS tend to be reported more frequently in areas
where DFS are abundant, even if traffic levels are relatively low,
(e.g., Dorchester County). The conscientious reporting and collecting
of DFS killed on roads at the Blackwater and Chincoteague NWRs, where
DFS are very abundant, likely results in a more complete count of
vehicle strikes than elsewhere. Vehicle strikes regularly occur at both
refuges, yet DFS remain abundant in both places and have expanded their
distribution at Chincoteague NWR despite vehicle strikes. Despite these
local events, across their range and owing to their population biology,
DFS populations continue to remain at current levels or expand, and we
conclude that vehicle strikes alone are not a pervasive threat or an
extinction factor for this species.
Summary of Factors A to E
A summary of our analysis of the five factors is provided in table
3 below. Based on our analysis, we conclude that no single factor or
combination of factors, such as the combined effects of development,
timber harvest, and sea level rise, poses a risk of extinction to the
DFS now or in the foreseeable future.
Table 3--Summary of Five-Factor Analysis Under the Act for DFS
----------------------------------------------------------------------------------------------------------------
Foreseeable trends in Does factor pose an
Factor Trends in past 40 years next 40 years extinction risk?
----------------------------------------------------------------------------------------------------------------
Habitat loss from development....... In the past 40 years, Development is expected No.
development increased to increase to 14
from 3 to 8 percent of percent of the land
the eight Maryland area in the 8 Maryland
counties; development counties and in Sussex
has increased in County, Delaware, as
Sussex County, well. Most projected
Delaware, as well. development will occur
Some habitat has been near urban areas where
lost, but most DFS do not occur.
development occurs However, 3 to 4
near existing towns percent of total DFS
where DFS are not as occupied habitat is
prevalent, and expected to be lost to
development often development. While
occurs on agricultural these losses may cause
rather than forest some small
land. subpopulations to
disappear, the
majority of the
occupied habitat will
continue to be
available. Despite
this development, the
DFS distribution is
expected to continue
to grow as it has in
the past.
Habitat loss from sea level rise.... In the past, losses in Under an extreme No.
occupied habitat have scenario of 0.61-m (2-
occurred in southern ft) inundation in 40
Dorchester County, years, considerable
although the acreage acreage will be lost
is not known. Sea or isolated in
level rise has southwestern
occurred in the past Dorchester County.
at the rate of 3.5 mm However, even if this
per year (about 1 ft loss occurred
per 100 years). immediately, this
subpopulation would
still retain 71 times
the MVP. The
Dorchester County
subpopulation would
continue to be the
largest subpopulation
and is very likely to
remain at levels well
above the MVP.
Habitat loss from timber harvest.... Sawtimber harvest has Recent declines in No.
occurred throughout timber harvest rates
the Delmarva and mill closings may
Peninsula. The harvest reduce the harvest
rate in Dorchester rate for some time.
County was 927 ha Increasing
(2,291 ac) per year. parcelization of land
This estimate will reduce the
(possibly an opportunities for
overestimate) appears large-scale timber
to have been production.
sustainable, as DFS Gentrification of the
have remained present Eastern Shore will
in Dorchester County likely shift public
and elsewhere despite values for forest
these harvest rates. management from timber
production to
management for
aesthetics and
wildlife. Thus, future
timber harvest rates
are not expected to
exceed past harvest
rates.
Habitat loss from short-rotation In the past, short- Since 1999, these lands No.
pine management. rotation pine harvests have been obtained by
have occurred on the States of Maryland
approximately 58,000 and Delaware and are
ac of the eight now managed for
Maryland Counties and sawtimber, which will
10,000 ac more in provide suitable DFS
Sussex County, habitat. Thus, we now
Delaware. These acres have 58,000 ac of land
were typically protected from
harvested before they development and
were mature enough to managed for sawtimber,
be DFS habitat. enabling use by DFS
that was previously
precluded.
Overutilization..................... Hunting seasons have Hunting seasons are No.
been closed since likely to remain
listing.. closed. If opened,
they would be limited
and managed very
carefully. Interest in
squirrel hunting has
declined
significantly, and
public attitudes
toward hunting have
changed to primarily
support hunting
species viewed as
needing population
management, such as
deer.
Disease or Predation................ Disease and predation These threats are not No.
have not been expected to increase,
significant threats and the increasing
for this species in distribution of the
the past 40 years. DFS lessens the impact
that disease and
predation could have
on this species.
[[Page 56701]]
Inadequacy of regulatory mechanisms. Several new Maryland In the next 40 years, No.
laws have appeared in forest conservation
the last 40 years to measures are expected
help conserve forest to continue, and the
areas. DFS occurrences programs that have
in Delaware and begun in Maryland are
Virginia are almost expected to continue
exclusively on or increase as they
protected lands. have in the past.
Easement programs that
protect private lands
from development have
begun in Delaware and
Virginia and are
expected to increase
in the future as well.
Other natural or manmade factors.... Forest pests and Forest pests and No.
vehicle strikes have vehicle strikes are
occurred in the past likely to continue to
40 years to some occur to some extent,
extent but have not but these factors have
limited the expansion not limited growth of
of the DFS the subpopulations in
distribution. the past and are not
expected to in the
future. As DFS
populations increase
in density, vehicle
strikes could increase
as the probability of
vehicle strikes is
primarily a function
of animal abundance.
----------------------------------------------------------------------------------------------------------------
Proposed Rangewide Determination
We have carefully assessed the best scientific and commercial
information available regarding past, present, and future threats to
the long-term viability of the DFS. The current range of DFS spans the
northern and southern portions of the Delmarva Peninsula, comprising
all three States, and extends from coastal areas to the interior of the
Delmarva Peninsula. The DFS inhabits a variety of forest types, from
hardwood-dominated to pine-dominated forests and from wetland to upland
forests, indicating an underlying genetic variability or behavioral
plasticity that should enhance the species' viability under changing
environmental conditions. Its relatively wide distribution also
provides redundancy of occupied forest across the landscape, which
further reduces extinction risk, and its continued occupancy of
woodlots over the past 20 to 30 years and the success of translocation
efforts indicate considerable resilience to stochastic events. We thus
expect the rangewide population of DFS not only to remain at recovery
levels but to grow and continue to occupy the full complement of
landscapes and forest types on the Delmarva Peninsula.
The DFS has met the recovery criteria for considering delisting,
and the analysis of potential threats shows that the range and
distribution of the subspecies is sufficient to withstand all
foreseeable threats to its long-term viability. We note, further, that
the PVA threshold of 95 percent probability of persistence over 100
years is indicative of an even higher probability of persistence over
the foreseeable future, defined as the next 40-years. After assessing
the best available information, we have determined that the DFS is no
longer in danger of extinction throughout all of its range, nor is it
likely to become so in the foreseeable future.
Significant Portion of the Range Analysis
Background
Having determined that the DFS is not endangered or threatened
throughout all of its range, we next consider whether there are any
significant portions of its range in which the DFS is in danger of
extinction or likely to become so. Under the Act and our implementing
regulations, a species may warrant listing if it is in danger of
extinction or likely to becomes so throughout all or a significant
portion of its range. The Act defines ``endangered species'' as any
species which is ``in danger of extinction throughout all or a
significant portion of its range,'' and ``threatened species'' as any
species which is ``likely to become an endangered species within the
foreseeable future throughout all or a significant portion of its
range.'' The term ``species'' includes ``any subspecies of fish or
wildlife or plants, and any distinct population segment [DPS] of any
species of vertebrate fish or wildlife which interbreeds when mature.''
We published a final policy interpreting the phrase ``Significant
Portion of its Range'' (SPR) on July 1, 2014 (79 FR 37578). The final
policy states that (1) if a species is found to be endangered or
threatened throughout a significant portion of its range, the entire
species is listed as endangered or threatened, respectively, and the
Act's protections apply to all individuals of the species wherever
found; (2) a portion of the range of a species is ``significant'' if
the species is not currently endangered or threatened throughout all of
its range, but the portion's contribution to the viability of the
species is so important that, without the members in that portion, the
species would be in danger of extinction or likely to become so in the
foreseeable future, throughout all of its range; (3) the range of a
species is considered to be the general geographical area within which
that species can be found at the time the Service or the National
Marine Fisheries Service makes any particular status determination; and
(4) if a vertebrate species is endangered or threatened throughout an
SPR, and the population in that significant portion is a valid DPS, we
will list the DPS rather than the entire taxonomic species or
subspecies.
The SPR policy is applied to all status determinations, including
analyses for the purposes of making listing, delisting, and
reclassification determinations. We use standard procedures for
analyzing whether any portion of the range is an SPR, regardless of the
type of status determination we are making. The first step in our
analysis of the status of a species is to determine its status
throughout all of its range. If we determine that the species is in
danger of extinction, or likely to become so in the foreseeable future,
throughout all of its range, we list the species as an endangered
species (or threatened species) and no SPR analysis is required. If the
species is neither in danger of extinction nor likely to become so
throughout all of its range, we next determine whether the species is
in danger of extinction or likely to become so throughout a significant
[[Page 56702]]
portion of its range. If it is, we list the species as an endangered
species or a threatened species, respectively; if it is not, we
conclude that listing the species is not warranted.
When we conduct an SPR analysis, we first identify any portions of
the species' range that warrant further consideration. The range of a
species can theoretically be divided into portions in an infinite
number of ways. However, there is no purpose to analyzing portions of
the range that are not reasonably likely to be both significant and
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 in those portions or
likely to become so within the foreseeable future. We emphasize that
answering these questions affirmatively is not a determination that the
species is endangered or threatened throughout a significant portion of
its range--rather, it is a step in determining whether a more detailed
analysis of the issue is required. In practice, a key part of this
analysis is questioning whether the threats are geographically
concentrated in some way. If the threats to the species are affecting
it uniformly throughout its range, no portion is likely to have a
greater risk of extinction, and thus would not warrant further
consideration. Moreover, if any concentration of threats applies only
to portions of the range that clearly do not meet the biologically
based definition of ``significant'' (i.e., the loss of that portion
clearly would not be expected to increase the vulnerability to
extinction of the entire species), those portions will not warrant
further consideration.
If we identify any portions that may be both (1) significant and
(2) in danger of extinction or likely to become so, we engage in a more
detailed analysis to determine whether these standards are indeed met.
As discussed above, to determine whether a portion of the range of a
species is significant, we consider whether, under a hypothetical
scenario, the portion's contribution to the viability of the species is
so important that, without the members in that portion, the species
would be in danger of extinction or likely to become so in the
foreseeable future throughout all of its range. This analysis considers
the contribution of that portion to the viability of the species based
on the conservation biology principles of redundancy, resiliency, and
representation. (These concepts can similarly be expressed in terms of
abundance, spatial distribution, productivity, and diversity.) The
identification of an SPR does not create a presumption, prejudgment, or
other predetermination as to whether the species in that identified SPR
is endangered or threatened. We must go through a separate analysis to
determine whether the species is in danger of extinction or likely to
become so in the SPR. To determine whether a species is endangered or
threatened throughout an SPR, we will use the same standards and
methodology that we use to determine if a species is endangered or
threatened throughout its range.
Depending on the biology of the species, its range, and the threats
it faces, it may be more efficient to address either the significance
question first, or the status question first. Thus, if we determine
that a portion of the range is not ``significant,'' we do not need to
determine whether the species is endangered or threatened there; if we
determine that the species is not endangered or threatened in a portion
of its range, we do not need to determine if that portion is
``significant.''
SPR Analysis for DFS
Applying the process described above, we evaluated the range of the
DFS to determine if any area could be considered a significant portion
of its range. As mentioned above, one way to identify portions for
further analyses is to identify any natural divisions within the range
that might be of biological or conservation importance. Based on
examination of the recovery plan (USFWS 1993, 2003; entire) and other
relevant and more recent information on the biology and life history of
the DFS, we determined that there are no separate areas of the range
that are significantly different from others or that are likely to be
of greater biological or conservation importance than any other areas.
We next examined whether any threats are geographically concentrated in
some way that would indicate the species could be in danger of
extinction, or likely to become so, in that area. Through our review of
potential threats, we identified some areas where DFS are likely to be
extirpated, including areas in Queen Anne's County, Maryland, where DFS
distribution is scattered and relatively isolated by roads and water,
and where future development is anticipated (see discussion of future
development trends under Factor A). We thus considered whether this
area in the northern portion of the range (see Factor A) may warrant
further consideration as a significant portion of its range.
As discussed previously, we anticipate 3 percent of the forest area
currently occupied by DFS to be lost to development by 2030. This
development would affect two small, isolated subpopulations in Queen
Anne's County that together constitute less than 0.5 percent of the
rangewide population. Additionally, the Queen Anne's County's landscape
is similar to nearby Kent, Talbot, and Caroline Counties in Maryland in
that it has hardwood-dominated forest patches in a landscape of
primarily agricultural land (USFWS 2012, table 2) and does not
represent a unique habitat type or ecological setting for the species.
While there is projected localized loss of habitat in areas of Queen
Anne's County (see Factor A), five large DFS subpopulations are
expected to remain viable across this broader northern portion of the
current range. We consider these subpopulations to be resilient, and
their distribution provides the necessary redundancy to offset loss of
local populations. The areas that may be lost due to development
represent a very small proportion of the range (3 percent), as well as
a very small proportion of the total population of the species (0.5
percent). Moreover, if the areas expected to be lost due to development
were in fact lost, that loss would not appreciably reduce the long-term
viability of the subpopulation, much less cause the species in the
remainder of its range to be in danger of extinction or likely to
become so. Therefore, there is not substantial information that the
small portions of the range in Queen Anne's County may be a significant
portion of the DFS's range.
We also expect loss of DFS-occupied forests from sea level rise in
Dorchester County, Maryland. The anticipated losses in this area are on
the southwestern periphery of the habitat supporting the largest
subpopulation of DFS. However, as discussed under Factor A, above,
these losses do not threaten either the subpopulation or the subspecies
with a risk of extinction, as there is ample unoccupied and
sufficiently connected habitat for displaced squirrels to colonize
(along with the evidence provided by successful translocations of the
ability of DFS to readily colonize new areas). Moreover, if the area
expected to be lost were in fact lost, that loss would not appreciably
reduce the long-term viability of the subpopulation, much less cause
the species in the remainder of its range to be in danger of extinction
or likely to become so. Therefore, there is not substantial information
that the
[[Page 56703]]
portion of the range that is expected to be lost from sea level rise
may be a significant portion of the DFS's range.
These are the only two portions of the range that contain
populations that may be affected by potential threats that could cause
the species to be in danger of extinction or likely to become so or
result in possible extirpation in those portions and thus warranting
review for an SPR determination. Finding that the potential losses in
small areas of Queen Anne's County do not cause cascading vulnerability
or reflect unique areas that are not represented elsewhere in the
species' range, and finding that loss of the area of Dorchester County
anticipated to be lost to sea level rise would not cause the remainder
of the species to be in danger of extinction or likely to become so, or
affect the continued viability of the Dorchester subpopulation, we do
not consider this subspecies to be in danger of extinction, or likely
to become so in the foreseeable future, in any significant portion of
its range. Further, given consideration (4) in the final SPR policy
(see Significant Portion of the Range Analysis, Background above), and
having not found the basis for an SPR determination on the grounds of
either significance of, or threat to, a portion of the current range of
the DFS, we also find that a DPS analysis is not warranted.
The DFS's current and projected resiliency, redundancy, and
representation should enable this subspecies to remain at recovered
population levels throughout all of its range, and even expand its
range over the foreseeable future. Having assessed the best scientific
and commercial data available and determined that the DFS is no longer
in danger of extinction throughout all or significant portions of its
range, nor is it likely to become so in the foreseeable future, we are
proposing to remove this species from the List of Endangered and
Threatened Species under the Act.
Effects of the Rule
This proposal, if made final, would revise 50 CFR 17.11(h) to
remove the DFS from the Federal List of Endangered and Threatened
Wildlife. The prohibitions and conservation measures provided by the
Act, particularly through sections 7 and 9, would no longer apply to
this species. Federal agencies would no longer be required to consult
with the Service under section 7 of the Act in the event that
activities they authorize, fund, or carry out may affect the DFS. There
is no critical habitat designated for this species.
This proposed rule, if made final, would also remove the
experimental population status of the DFSs that were introduced to the
Assawoman State Wildlife Management Area in Sussex County, Delaware.
This designation was established on September 13, 1984 (49 FR 35951-
35955).
Post-Delisting Monitoring Plan
Section 4(g)(1) of the Act requires us, in cooperation with the
States, to implement a monitoring program for not less than 5 years for
all species that have been recovered and delisted. The purpose of this
requirement is to develop a program that detects the failure of any
delisted species to sustain itself without the protective measures
provided by the Act. If, at any time during the monitoring period, data
indicate that protective status under the Act should be reinstated, we
can initiate listing procedures, including, if appropriate, emergency
listing.
Notice of availability of a draft DFS post-delisting monitoring
plan. We are announcing the availability for public review of a draft
post-delisting monitoring plan for the DFS. The draft PDM plan can be
obtained upon request from the Chesapeake Bay Field Office (see
ADDRESSES above) and is posted in the docket on http://www.regulations.gov and on the Chesapeake Bay Field Office Web page at:
http://www.fws.gov/chesapeakebay.
This draft plan builds upon and continues the research and
monitoring that have been conducted to date. In general, the plan
proposes that the Service and State natural resource agencies will: (1)
Continue to map all DFS sightings and occupied forest to delineate the
distribution and range, and (2) assess the occupancy of DFS in a sample
of forest tracts to estimate the relative proportion of viable DFS
populations versus extirpations across the range.
The draft PDM plan identifies measurable management thresholds and
responses for detecting and reacting to significant changes in the
DFS's protected habitat, distribution, and ability to remain at
recovered population levels. If declines are detected equaling or
exceeding these thresholds, the Service, along with other post-
delisting monitoring participants, will investigate causes, including
consideration of habitat changes, stochastic events, or any other
significant evidence. Results will be used to determine if the DFS
warrants expanded monitoring, additional research, additional habitat
protection, or resumption of Federal protection under the Act.
The final PDM plan and any future revisions will be posted on our
Endangered Species Program's national Web page at: http://endangered.fws.gov and on the Chesapeake Bay Field Office Web page at:
http://www.fws.gov/chesapeakebay.
Required Determinations
Clarity of the Rule
We are required by Executive Orders 12866 and 12988 and by the
Presidential Memorandum of June 1, 1998, to write all rules in plain
language. This means that each rule we publish must:
(a) Be logically organized;
(b) Use the active voice to address readers directly;
(c) Use clear language rather than jargon;
(d) Be divided into short sections and sentences; and
(e) Use lists and tables wherever possible.
If you feel that we have not met these requirements, send us
comments by one of the methods listed in ADDRESSES. To better help us
revise the rule, your comments should be as specific as possible. For
example, you should tell us the names of the sections or paragraphs
that are unclearly written, which sections or sentences are too long,
the sections where you feel lists or tables would be useful, etc.
National Environmental Policy Act
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.), need not be
prepared in connection with regulations pursuant to section 4(a) of the
Act. We published a notice outlining our reasons for this determination
in the Federal Register on October 25, 1983 (48 FR 49244).
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994,
Government-to-Government Relations with Native American Tribal
Governments (59 FR 22951), E.O. 13175, and the Department of the
Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with recognized Federal
Tribes on a government-to-government basis. In accordance with
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights,
Federal-Tribal Trust Responsibilities, and the Endangered
[[Page 56704]]
Species Act), we readily acknowledge our responsibilities to work
directly with Tribes in developing programs for healthy ecosystems, to
acknowledge that tribal lands are not subject to the same controls as
Federal public lands, to remain sensitive to Indian culture, and to
make information available to Tribes. As no Federally recognized Tribes
occur within the squirrel's Delmarva Peninsula range, we have
determined that no Tribes will be affected by this rule.
References Cited
A complete list of all references cited in this final rule is
available at: http://www.regulations.gov at Docket No. FWS-R5-ES-2014-
0021, or upon request from the Chesapeake Bay Field Office (see
ADDRESSES).
Authors
The primary authors of this proposed rule are staff members of the
Service's Chesapeake Bay Field Office (see ADDRESSES and FOR FURTHER
INFORMATION CONTACT).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, we hereby propose to amend part 17, subchapter B of
chapter I, title 50 of the Code of Federal Regulations, as set forth
below:
PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245; unless
otherwise noted.
Sec. 17.11--[Amended]
0
2. Amend section 17.11(h) by removing both entries for ``Squirrel,
Delmarva Peninsula fox'' under ``Mammals'' from the List of Endangered
and Threatened Wildlife.
Sec. 17.84--[Amended]
0
3. Amend Sec. 17.84 by removing and reserving paragraph (a).
Dated: September 5, 2014.
Daniel M. Ashe,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2014-22063 Filed 9-22-14; 8:45 am]
BILLING CODE 4310-55-P