[Federal Register Volume 77, Number 167 (Tuesday, August 28, 2012)]
[Proposed Rules]
[Pages 51958-51964]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-20820]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2011-0012; 4500030113]
Endangered and Threatened Wildlife and Plants; 12-Month Finding
on a Petition To List the Bay Skipper as Endangered or Threatened
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition finding.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
12-month finding on a petition to list the Bay skipper (Euphyes
bayensis) as an endangered or threatened species under the Endangered
Species Act of 1973, as amended, and to designate critical habitat.
After review of the best available scientific and commercial
information, we find that listing the Bay skipper is not warranted at
this time. However, we ask the public to submit to us any new
information that becomes available concerning the threats to the Bay
skipper or its habitat at any time.
DATES: The finding announced in this document was made on August 28,
2012.
ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R4-ES-2011-0012. Supporting
documentation we used in preparing this finding is available for public
inspection, by appointment, during normal business hours at the U.S.
Fish and Wildlife Service, Mississippi Field Office, 6578 Dogwood View
Parkway, Jackson, MS 39213. Please submit any new information,
materials, comments, or questions concerning this finding to the above
address.
FOR FURTHER INFORMATION CONTACT: Stephen Ricks, Mississippi Field
Office (see ADDRESSES); by telephone 601-321-1122, or by facsimile 601-
965-4340 If you use a telecommunications device for the deaf (TDD),
please call the Federal Information Relay Service (FIRS) at 800-877-
8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.), requires
that, for any petition to revise the Federal Lists of Endangered and
Threatened Wildlife and Plants that contains substantial scientific or
commercial information that listing the species may be
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warranted, we make a finding within 12 months of the date of receipt of
the petition. In this finding, we will determine that the petitioned
action is: (1) Not warranted, (2) warranted, or (3) warranted, but the
immediate proposal of a regulation implementing the petitioned action
is precluded by other pending proposals to determine whether species
are threatened or endangered, and expeditious progress is being made to
add or remove qualified species from the Federal Lists of Endangered
and Threatened Wildlife and Plants. We must publish these 12-month
findings in the Federal Register.
Previous Federal Actions
The Bay skipper was identified as a candidate for protection under
the Act in the November 21, 1991, Federal Register (56 FR 58804). It
was assigned a Category 2 status designation, which was given to those
species for which there was some evidence of vulnerability, but for
which additional biological information was needed to support a
proposed rule to list as an endangered or threatened species. Assigning
categories to candidate species was discontinued in 1996 (Notice of
Candidate Review; February 28, 1996; 61 FR 7596), and only species for
which the Service has sufficient information on biological
vulnerability and threats to support issuance of a proposed rule are
now regarded as candidate species. Due to a lack of information on the
Bay skipper, it was no longer considered as a candidate species as of
1996.
On January 4, 2010, we received a petition dated December 29, 2009,
from WildEarth Guardians and Xerces Society for Invertebrate
Conservation requesting that the Bay skipper be listed as an endangered
or threatened species and critical habitat be designated under the Act.
The petition clearly identified itself as such and included the
requisite identification information for the petitioners, as required
by 50 CFR 424.14(a). In a January 25, 2010, letter to the petitioners,
we acknowledged receipt of the petition, and stated that due to prior
workload and limited funding, we would not be able to address the
petition at that time, but would complete the action when workload and
funding allowed. On May 6, 2010, we received a 60-day notice of intent
(NOI) to sue under the provisions of the Act from petitioners for our
alleged failure to make a finding within 90 days of receipt of the
petition. In a June 11, 2010, letter to the petitioners, we
acknowledged receipt of the NOI and stated that a publication date for
the 90-day finding could not be predicted at that time. Funding became
available during fiscal year 2011, and on July 12, 2011, we published a
90-day finding (76 FR 40868) that the petition presented substantial
scientific or commercial information indicating that listing this
species may be warranted, and requested scientific and commercial data
and other information regarding this species. This notice constitutes
the 12-month finding on the January 4, 2010, petition to list the Bay
skipper as an endangered species.
Species Information
The Bay skipper, a small butterfly, was described as Euphyes
bayensis by Shuey (1989) from Bay St. Louis, Hancock County,
Mississippi. Shuey (1993) reported on the phylogeny (the history of the
evolution of a species) within the Euphyes genus, finding that E.
bayensis is a species in the Euphyes dion complex. During our status
review, we received comments from Texas Parks and Wildlife Department
(TPWD) questioning the taxonomic validity of the Bay skipper,
particularly the lack of quantitative morphological studies of Texas
populations (TPWD 2011). While we agree that additional studies would
be useful, the species has been appropriately described, and all
subsequent peer-reviewed taxonomic treatments and collection accounts
consider the taxon as valid (e.g., Gatrelle 2000, p. 4; Pelham 2008, p.
93; Marks 2011a, pp. 92-94).
The Bay skipper has a wingspan of 1.5 to 1.75 inches (in) (3.7 to
4.4 centimeters (cm)). Males are black with a large orange patch on the
top of the wings, and have a prominent black stigma (defined mark) on
the forewing. The females are dark brown with yellow spots on their
forewing and a yellow streak on their hindwing. The ventral (bottom)
sides of both front and hind wings of the females are a shade of brown
that is paler than the dorsal (upper) side, and have pale yellow spots
on the forewing, with two yellow streaks from the base to the margin
(Shuey 1989, p. 165; Vaughan and Shepherd 2005, pp. 1-2; Butterflies
and Moths of North America (BMNA) 2009, p. 1). The Bay skipper is
similar in appearance to the Dion skipper (Euphyes dion), but is
distinguished by a brighter shade of orange and narrower black borders
on the dorsal (top) side of the wings (Shuey 1989, p. 166).
The life history and habitat requirements of the Bay skipper are
poorly known. Bay skippers appear to have two major flight periods
(late spring and fall), and the potential to produce two generations
per year. The gap between the flight periods suggests that the larvae
produced during the spring flight period may aestivate (become dormant)
in the summer. The species may overwinter (hibernate) in the larval
form. Aestivating and hibernating larvae are probably in the third or
fourth instar (period between molts) (Vaughan and Shepherd 2005, p. 2).
Bay skippers have been observed only in association with estuarine
herbaceous marsh, including brackish and freshwater marshes. The larval
food plant is unknown, but Cladium sp. (sawgrass), Phragmites sp.
(reeds), and Schoenopletus sp. (bulrush) are potential larval host
plants (NatureServe 2009 as cited in WildEarth Guardians and Xerces
Society for Invertebrate Conservation, p. 7; Salvato 2011, p. 14).
Adults have been observed feeding on a variety of nectar-producing
plants adjacent to wetlands, including Solidago sp. (goldenrod),
Verbena brasiliensis (Brazilian vervain), and Lippia sp. (frog fruit)
(Marks 2011a, pp. 92-94; Marks 2011b).
Until recently, the Bay skipper was considered to occur in only two
locations: Bay St. Louis, Hancock County, Mississippi, and the Anahuac
National Wildlife Refuge (NWR) (part of the Texas Chenier Plains NWR
Complex), Chambers and Jefferson Counties, Texas. The lack of records
suggested that the species had a very limited range and was very rare
(Vaughan and Shepherd 2005, p. 2; NatureServe 2009, 2011). The Bay St.
Louis locality was severely damaged by Hurricane Katrina in 2005, and
it was unknown if the species continued to survive in that locality.
The Anahuac NWR and surrounding areas were inundated by Hurricane Ike
in 2008, and no Bay skippers had since been reported at that location
(NatureServe 2011, WildEarth Guardians and Xerces Society for
Invertebrate Conservation 2009, p. 9).
As part of the status review following the 90-day finding, we
contacted lepidopterists along the Gulf Coast for additional records,
photographs, specimens, and other information on the distribution and
abundance of the Bay skipper. We also conducted a 1-week survey for the
Bay skipper at the two known localities, and other potentially suitable
habitat along the Gulf Coast between Galveston Bay, Texas, and
Sandestin, Florida (Salvato 2011 pp. 1-28). No Bay skippers were found
on the Anahuac NWR, or at the type locality in Bay St. Louis. However,
we were able to identify seven additional localities where Bay skippers
have been recently sighted, two in Texas and five in Cameron Parish,
Louisiana. These new
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localities were documented by publication (Gatrelle 2000, p. 4; Marks
2011a, pp. 92-94; Marks 2011b; Salvato 2011, p. 15), photographs,
pinned specimens, and observation of the species during the 2011 survey
(Salvato 2011 pp. 1-14). Recent sightings at an additional three
locations in Cameron Parish, Louisiana, were unconfirmed (Salvato 2011,
pp. 1-3). All of the new confirmed sites are within or adjacent to
wildlife refuges (Texas Point NWR, Sabine NWR, Cameron Prairie NWR,
Rockefeller Wildlife Refuge), a State park (Sea Rim State Park), or a
nature center (Baytown Nature Center) (Salvato 2011, pp. 1-14).
Our survey and our review of the best available scientific and
commercial information demonstrates that efforts to document the Bay
skipper have been limited and localized, and the Bay skipper is more
widely distributed than previously believed (Salvato 2011, pp. 1-14;
Marks 2011a, pp. 92-94). It is likely that additional populations occur
along the Gulf Coast, as extensive and apparently suitable estuarine
marsh habitats with appropriate nectar and potential host plants were
observed at numerous sites on both public and private lands (Salvato
2011, pp. 1-14). Within the currently known range of the Bay skipper
(East Texas to Mississippi), there are 10 national wildlife refuges,
seven State wildlife refuges, two State parks, one State wetland
conservation area, and one national park that contain, protect, and
manage for estuarine marsh habitats known to be occupied, or
potentially occupied, by the species. Extensive areas of privately
owned estuarine marsh habitats are also present, and such habitats are
not conducive to development, farming, or other land use practices
potentially detrimental to Bay skipper habitat.
Summary of Information Pertaining to the Five Factors
Section 4 of the Act and its implementing regulations at 50 CFR 424
set forth the procedures for adding a species to, or removing a species
from, the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, a species may be determined
to be an endangered or threatened species based on any of the following
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.
In making this finding, information pertaining to the Bay skipper
in relation to the five factors provided in section 4(a)(1) of the Act
is discussed below. In considering what factors might constitute
threats, we must look beyond the mere exposure of the species to the
factor to determine whether the species responds to the factor in a way
that causes actual impacts to the species. If there is exposure to a
factor, but no response, or only a positive response, that factor is
not a threat. If there is exposure and the species responds negatively,
the factor may be a threat and we then attempt to determine how
significant a threat it is. If the threat is significant, it may drive
or contribute to the risk of extinction of the species such that the
species warrants listing as threatened or endangered as those terms are
defined by the Act. This does not necessarily require empirical proof
of a threat. The combination of exposure and some corroborating
evidence of how the species is likely impacted could suffice. The mere
identification of factors that could impact a species negatively is not
sufficient to compel a finding that listing is appropriate; we require
evidence that these factors are operative threats that act on the
species to the point that the species meets the definition of a
threatened or endangered species under the Act.
In making our 12-month finding on the petition, we considered and
evaluated the best available scientific and commercial information.
A. The Present or Threatened Destruction, Modification, or Curtailment
of the Species' Habitat or Range
Until recently, the Bay skipper was recognized as occurring in only
two localized areas: Bay St. Louis, Mississippi, and the Anahuac NWR,
Texas (e.g., Vaughan and Shepherd 2005, pp. 1-2; NatureServe 2011).
Habitat for the Bay St. Louis, Mississippi, population of the Bay
skipper was severely damaged by Hurricane Katrina in 2005, and the
Anahuac NWR, Texas, population was inundated by Hurricane Ike in 2008.
There was concern that one or both of these populations of the Bay
skipper might have been extirpated due to habitat loss or modification
by the hurricane activity (WildEarth Guardians and Xerces Society for
Invertebrate Conservation 2009, p. 9), and there was additional concern
that the species could be extinct.
Given these concerns, we conducted a 1-week survey that included
the historical occurrence locations, as well as multiple points in
between, during a week of the September 2011 flight period (Salvato
2011, pp. 1-28). This limited survey failed to locate the species at
either of the previously occupied locations of Bay St. Louis,
Mississippi, or Anahuac NWR, Texas. However, only a few hours were
spent searching each of the historical locations, thus neither the
continued presence nor the extirpation of the species from these two
sites could be confirmed, as habitat at both locations appeared to be
suitable to sustain the species (Salvato 2011, pp. 5-6, 11). As
discussed above, the survey did confirm seven extant site locations of
the Bay skipper in Chambers and Jefferson Counties, Texas, and in
Cameron Parish, Louisiana (Gatrelle 2000, p. 4; Wauer 2006; Marks
2011a, pp. 92-94; Salvato 2011, pp. 1-14).
Although all of the site locations are known to have experienced
one or more severe storm events by recent hurricanes (i.e., Hurricane
Katrina 2005, Hurricane Rita 2005, Hurricane Gustav 2008, Hurricane Ike
2008), the Bay skipper continues to persist at the 7 newly confirmed
locations. The Bay skipper is endemic to, and adapted to, estuarine
marsh habitats. Such habitats in the northern Gulf of Mexico are
frequently subject to tropical storms and hurricanes, and the area has
experienced an increase in storm activity (Goldenberg et al. 2001, p.
474-475). Some researchers believe the increase in tropical storm and
hurricane intensity, duration, and frequency can be attributed to
warming of the Gulf of Mexico's water temperatures (Karl et al. 2009,
pp. 5-6).
Researchers studying butterfly community response to hurricane and
tropical storm events have documented local species declines and
extirpations; however, this research has also found that those
butterfly species most closely associated with the local vegetation
survived and rapidly recovered from periodic storm impacts (Salvato and
Salvato 2007, p. 160). Others recovered more gradually. For example,
although the endangered Miami blue butterfly (Cyclargus thomasi
bethunebakeri) declined on Bahia Honda following impacts from
hurricanes Dennis, Katrina, and Wilma during 2005, the population
returned to pre-storm abundance within 2 years following the storms
(Salvato and Salvato 2007, p. 160).
Estuarine plant species that are considered to be utilized by Bay
skipper larvae include sawgrass, reeds, and bulrush (Salvato 2011, pp.
1-14). Adult Bay skippers have been observed
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feeding on native and exotic flowering plants such as goldenrod,
Brazilian vervain, and frog fruit, as well as a variety of other annual
and perennial nectar-producing plants adjacent to wetlands (Marks
2011a, pp. 92-94). All of these plants are common or abundant
throughout the range of the Bay skipper. These plants are rapid
colonizers under appropriate conditions, with seed dispersal occurring
via water, wind, or animal transport. All of these plants will rapidly
recover from severe storm impacts, as well as colonize new habitats as
conditions become appropriate. The discovery of seven new site
locations for the Bay skipper, all of which have been recently impacted
by hurricane activity, indicates that this butterfly species, and the
plants that it utilizes, are adapted to surviving severe storm events.
There are concerns that Bay skipper habitats could be negatively
affected by sea level rise (WildEarth Guardians and Xerces Society for
Invertebrate Conservation 2009, p. 9), and that impacts from storm
events could be compounded by projected sea level rise (Karl et al.
2009, pp. 5-6). Since 2003, global mean sea level rise has been
estimated at approximately 2.5 mm (0.10 in)/year (McMullen and Jabbour
2009, p. 26). Estimates of mean sea level trends (including subsidence)
along the Gulf of Mexico within the range currently or potentially
occupied by Bay skipper vary from 2.1 mm (0.0827 in)/year at Pensacola,
Florida, to 9.6 mm (0.378 in)/year at Eugene Island, Louisiana, and
6.84 mm (0.2693 in)/year at Galveston, Texas (National Oceanographic
and Atmospheric Administration 2012; see also Mitchum 2011 pp. 8-9). As
noted above, during our status review, we obtained information on
potential larval host and nectar plant species utilized by the Bay
skipper, all of which are widely distributed, adapted to estuarine
habitats, and capable of rapidly colonizing new habitats as conditions
become appropriate. Additionally, the flight capability of the Bay
skipper and its life cycle (e.g., at least two broods per year) provide
an ability for the species to accommodate local habitat changes.
During our survey, five of the seven newly recognized butterfly
locations were found in Louisiana estuarine marshes. Coastal Louisiana
contains the largest estuarine herbaceous marsh in the United States;
however, it is also experiencing the highest rate of wetland loss in
the country (Couvillion et al. 2011, p. 1). While it is likely that
some Bay skipper habitats have been detrimentally affected by coastal
marsh erosion in Louisiana, potential curtailment of range cannot be
quantified due to the lack of information on historical range and
specific habitat. Rates of wetland loss in Louisiana have been
decreasing since 1978 (Couvillion et al. 2011, p. 12), and the
estuarine herbaceous marsh habitat continues to be a dominant feature
of the coastal landscape. In addition, multiple projects have been
completed, are underway, or are under evaluation in Louisiana to
further reduce losses and restore wetlands (see Other Conservation
Efforts, below).
There is no available information supporting concerns that land
management actions (e.g., livestock grazing, rice farming, land
management involving conventional farm machinery, prescribed fires,
herbicide use, water control) (WildEarth Guardians and Xerxes Society
2009, pp. 10-11) are negatively affecting the Bay skipper. Estuarine
marsh habitats where the Bay skipper have been identified are low-
elevation herbaceous wetlands not suitable or utilized directly for
grazing or farming, and are generally not subject to impacts by
conventional farm machinery. Marshes may be periodically burned;
however, fire is a natural component of the estuarine ecosystem, and
managed fires are localized, seasonal, and beneficial to Bay skipper
estuarine marsh habitats. Due to their low elevations and lack of
agricultural potential, estuarine ecosystems are generally not subject
to herbicide or pesticide use. As noted in the Background, above, there
are multiple State or Federal refuges and protected areas that are
managed for estuarine biodiversity. Herbicide and pesticide use in such
areas is either restricted or closely managed. For example, on the
Anahuac National Wildlife Refuge, herbicides are used only to combat
exotic plant species (Cooper, pers. comm. 2010). While highway right-
of-ways may be periodically subject to herbicide control measures, this
would seasonally affect only a small proportion of the nectaring plants
available to butterflies in any given area.
Other Conservation Efforts
Following the severe impacts of Hurricanes Katrina and Rita in
2005, the Coastal Protection and Restoration Authority (CPRA) was
established by the Louisiana legislature to work with other State
agencies, Federal agencies, private industries, and other
nongovernmental entities. One of their primary goals is to conserve and
restore Louisiana coastal wetlands and their role in hurricane
protection. Since 2005, over 200 restoration and protection projects
have been constructed, are in progress, or are proposed (CPRA 2012, pp.
22-25). Projects that protect, enhance, or restore estuarine herbaceous
marshes include water and sediment diversions, marsh nourishment, marsh
creation, shoreline protection, and hydrologic restoration (CPRA 2012,
pp. 115-139).
The National Wildlife Refuge System Improvement Act of 1997 and the
Fish and Wildlife Service Manual (601 FW 3, 602 FW 3) require
maintaining biological integrity and diversity, comprehensive
conservation planning for each refuge, and set standards to ensure that
all uses of refuges are compatible with their purposes and the Refuge
System's wildlife conservation mission. The comprehensive conservation
plan (plan) addresses conservation of fish, wildlife, and plant
resources and their related habitats, while providing opportunities for
compatible wildlife-dependent recreation uses. An overriding
consideration reflected in these plans is that fish and wildlife
conservation has first priority in refuge management, and that public
use be allowed and encouraged as long as it is compatible with, or does
not detract from, the Refuge System mission and refuge purpose(s).
The Texas Chenier Plains National Wildlife Refuge Complex, which
includes Anahuac and Texas Point National Wildlife Refuges, and the
Southwest Louisiana National Wildlife Refuge Complex, which includes
Cameron and Sabine National Wildlife Refuges, encompass most of the
known, and much of the potential, habitat for Bay skipper in Texas and
Louisiana (see Background, above). Both Refuge complexes have developed
plans that prohibit, or closely control, land use management actions
which may be harmful to maritime habitats and wildlife species,
including the Bay skipper (U.S. Fish and Wildlife Service 2006, 2007,
2008). Currently, the Bay skipper is not specifically named in the
plans for each refuge; however, protection is provided to the species
indirectly through management of potentially harmful land uses, and the
plans can, and will be, amended to incorporate new information on
locations and habitat management for Bay skipper (Hunter, pers. comm.
2012).
The Bay skipper is also found on the Rockefeller Wildlife Refuge,
managed by the Louisiana Department of Wildlife and Fisheries, and Sea
Rim State Park, managed by Texas Parks and Wildlife Department.
Management activities on State Parks and Refuges are guided by State
Wildlife Action Plans (Louisiana Department of Wildlife and Fisheries
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2005, Texas Parks and Wildlife Department 2005), which provide a
framework to recognize, manage, and conserve imperiled State wildlife.
The Bay skipper is recognized as a species of management concern in the
Texas Wildlife Action Plan (Texas Parks and Wildlife Department 2005,
p. 59), and will be considered for inclusion in the upcoming revision
of the Louisiana Wildlife Action Plan list (Bass, pers. comm. 2012).
State Wildlife Action Plans also alert private and corporate landowners
of the status, habitats, and general locations of wildlife species of
concern, and help ensure consideration of the potential presence of the
species and its habitat requirements during Federal and State permit
review processes.
Summary of Factor A
In summary, we find that while Bay skippers are periodically and
locally affected by hurricanes and tropical storms, the species and
their habitats are adapted to such events. We find no evidence that the
Bay skipper and the maritime plant communities upon which it depends
will be unable to shift their distributions to accommodate current
rates of sea level rise. Their flight capability, and the production of
two generations per year of the Bay skipper, should enable the species
to rapidly colonize areas impacted by severe storm events, as well as
adjust to maritime habitat shifts that may occur from sea level rise.
We also find little evidence that land management actions are now
having, or have in the past, had a wide negative effect on the species.
Additionally, the magnitude of all of these potential threats to the
species has also been reduced by the discovery and recognition of the
Bay skipper's wider distribution, and ongoing efforts to protect and
enhance estuarine marsh habitats. Therefore, our review of the best
available scientific and commercial information does not provide
evidence that the present or threatened destruction, modification, or
curtailment of habitat and range represents an ongoing and significant
threat to the Bay skipper now or in the future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Rare butterflies and moths can be highly prized by collectors, and
an international trade exists for some species for both live and
decorative markets, as well as the specialist trade that supplies
hobbyists, collectors, and researchers (e.g., Collins and Morris 1985,
pp. 155-179; http://www.theinsectcollector.com/acatalog/specimens_real.htm). However, the primary reason that little is known about the
Bay skipper, as discussed above, is a lack of scientific or educational
collecting in the area it inhabits. While we found some information
regarding targeted scientific collecting activity to better document
the distribution of the Bay skipper (Salvato 2011, pp. 1-14; Marks
2011a, pp. 92-94; Marks 2011b), our status review did not indicate that
any commercial or recreational trade in the species is occurring.
Therefore, our review of the best available scientific and commercial
information does not indicate that overutilization of the Bay skipper
for commercial, recreational, scientific, or educational purposes is a
threat to the species now or in the future.
C. Disease or Predation
Studies suggest that various diseases and parasites (e.g.,
baculovirus, Ophryocystis sp.) have the potential to negatively impact
butterflies (Altizer and Oberhauser 1999, p. 76; Hesketh et al. 2010),
and butterflies have many natural predators including frogs, lizards,
birds, carnivorous insects, and spiders. However, the best available
information does not indicate that disease or pathogens are
specifically affecting Bay skippers, nor does it provide any evidence
regarding the effect of natural predation on Bay skipper populations.
The recently confirmed additional populations and a wider range for the
Bay skipper reduce any potential vulnerability the species may have to
extirpation by disease or predation in the future. Based on our
analysis of the best available information, we have determined that
neither disease nor predation are significant threats to the Bay
skipper now or in the future.
D. The Inadequacy of Existing Regulatory Mechanisms
The Bay skipper is classified as an S1 species in both Texas and
Mississippi (NatureServe 2011). The S1 designation, based upon the
number of occurrences within a State, is considered ``critically
imperiled--State level'' under the NatureServe construct. However, no
formal or regulatory consideration is provided to the species or its
habitat in Texas or Mississippi as a result of this classification. The
Bay skipper has only recently been discovered in Louisiana (Marks
2011a, pp. 92-94; Salvato 2011, pp. 1-15), but receives no formal
protections in that State. The Louisiana Natural Heritage Program has
been informed of the discovery of the species in the State, and is
currently working to update the NatureServe list to reflect that it has
been found in the State (Bass pers. comm. 2012).
As noted under ``Other Conservation Efforts,'' above, the Louisiana
CPRA has been established to work with other State and Federal agencies
and nongovernmental entities to protect and restore Louisiana coastal
wetlands, which include Bay skipper herbaceous marsh habitats. In
addition, Bay skipper populations occurring on National Wildlife
Refuges are protected by the National Wildlife Refuge System
Improvement Act of 1997 and its implementing regulations, which require
maintaining biological integrity and diversity on refuge lands. Bay
skipper populations occurring in private estuarine wetland habitats are
generally protected under section 404 of the Clean Water Act, which
established a project review and permitting process to avoid or
minimize wetland impacts, and which requires mitigation of unavoidable
impacts.
Therefore, based on our analysis of the best available scientific
and commercial information, there is currently no evidence that the
inadequacy of existing regulatory mechanisms is a threat to the Bay
skipper now or in the future.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Climate Change Effects
Our analyses under the Act include consideration of ongoing and
projected changes in climate. The terms ``climate'' and ``climate
change'' are defined by the Intergovernmental Panel on Climate Change
(IPCC). ``Climate'' refers to the mean and variability of different
types of weather conditions over time, with 30 years being a typical
period for such measurements, although shorter or longer periods also
may be used (IPCC 2007, p. 78). The term ``climate change'' thus refers
to a change in the mean or variability of one or more measures of
climate (e.g., temperature or precipitation) that persists for an
extended period, typically decades or longer, whether the change is due
to natural variability, human activity, or both (IPCC 2007, p. 78).
Various types of changes in climate can have direct or indirect effects
on species. These effects may be positive, neutral, or negative and
they may change over time, depending on the species and other relevant
considerations, such as the effects of interactions of climate with
other variables (e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-
19). In our
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analyses, we use our expert judgment to weigh relevant information,
including uncertainty, in our consideration of various aspects of
climate change.
Rising Sea Levels
As noted under Factor A (above), annual rates of sea level rise
along the Gulf of Mexico within the range currently or potentially
occupied by Bay skipper vary from 2.1 mm (0.0827 in)/year at Pensacola,
Florida, to 9.6 mm (0.378 in)/year at Eugene Island, Louisiana, and
6.84 mm (0.2693 in)/year at Galveston, Texas (National Oceanographic
and Atmospheric Administration 2012), and the estuarine plant
communities that support the Bay skipper are composed of species that
have the ability to rapidly colonize new areas under appropriate
conditions and, therefore, can shift their distributions to accommodate
currently predicted rates of sea level rise. Additionally, the flight
capability of the Bay skipper and its ability to produce two
generations per year enable the species to adjust to and exploit
estuarine habitat shifts that may occur from gradual sea level rise.
Also noted under Factor A (above), is the resilience of estuarine-
adapted butterfly species to major storm events subjecting their
habitats to inundation. This is supported by the discovery of new
populations of Bay skipper (Salvato 2011, pp. 1-15) in areas that have
recently been subjected to one or more severe tropical storms (see
Background, above). Rising temperatures associated with climate change
and rising sea levels may also present new host and nectaring plant
opportunities for Bay skipper (e.g., Pateman et al. 2012, pp. 1028-
1030). Our review of the best available information does not indicate
that sea level rise is a significant threat to the species.
Increased Intensity and Frequency of Storms
Climate change can cause more frequent and severe storms, including
hurricanes. This can have a number of detrimental effects on butterfly
populations, including habitat loss, destruction of preferred food and
host plants, flooding, and extirpation of affected populations. There
is concern that hurricanes may have extirpated Bay skipper populations
from Bay St. Louis, Mississippi, and Anahuac NWR, Texas, due to habitat
damage and inundation. However, seven new populations of Bay skipper
were discovered, all of them in locations that have experienced one or
more recent hurricane storm events. This indicates that while severe
storms have the potential to negatively affect Bay skipper populations,
the species is capable of recovering from storm damage, even when
storms occur closely spaced in time, such as Hurricanes Gustav and Ike
in 2008. Salvato and Salvato (2007) noted that butterflies that were
quick to recover after severe storms were those species associated with
the local vegetation. The Bay skipper is endemic to estuarine marsh
habitats and associated with vegetation that is quick to colonize new
areas under appropriate conditions, so the Bay skipper is likely
capable of recovering quickly from severe storms. The species also has
the advantage of producing two generations per year, allowing for
faster recolonization of damaged areas. Our review of the best
available scientific and commercial information does not indicate that
increased frequency and intensity of storms is a significant threat to
the species.
Biological Vulnerability
Species with small population sizes and restricted ranges are more
vulnerable to random natural or human-induced events (e.g., storms,
droughts, spills, etc.). There were concerns that the Bay skipper may
have been extirpated after the habitat for the Bay St. Louis,
Mississippi, population of Bay skipper was severely damaged by
Hurricane Katrina in 2005, and the habitat for the Anahuac NWR, Texas,
population was inundated by Hurricane Ike in 2008 (WildEarth Guardians
and Xerces Society for Invertebrate Conservation 2009, p. 9). However,
the discovery of additional populations, inhabiting locations which
were not previously known to be occupied, with limited survey effort at
the end of the September 2011 flight season, indicates that the range
and total population size of the Bay skipper is poorly known and may
neither be restricted, nor small (see Background). Additionally, apart
from localized stochastic events, our review of the best available
scientific and commercial information did not provide evidence of any
specific threats to the known populations (see Factors A, B, C, and D,
above), nor did it indicate that the Bay skipper is biologically
vulnerable due to restricted range and small population size.
Pesticide Use
Butterflies and their larvae are vulnerable to pesticides; however,
the estuarine marsh habitats where the species occurs are not subject
to activities requiring pesticide use (see Factor A, above), and there
is no available evidence to indicate that the Bay skipper is being
impacted or is likely to be impacted by pesticide or other chemical
use.
Summary of Factor E
The discovery of additional populations and a wider range for the
Bay skipper reduces the species' potential vulnerability to stochastic
events. In summary, our review of the best available scientific and
commercial information found no evidence that other natural or manmade
factors, such as rising sea level due to climate change, biological
vulnerability from restricted range or small population size, or
pesticide use are threats to the Bay skipper either now or in the
future.
Finding
As required by the Act, in assessing whether the Bay skipper is an
endangered or threatened species throughout all of its range, we
considered the five factors. We examined the best scientific and
commercial information available regarding the past, present, and
future threats faced by the Bay skipper. We reviewed the petition,
information available in our files, other available published and
unpublished information, and we consulted with recognized butterfly
experts and other Federal and State agencies. We also conducted a brief
survey for the species (Salvato 2011, pp. 1-28).
Information acquired during our review of the Bay skipper indicated
that there has been an increase in the known range of the species, and
an expansion of the number of known site occurrences for the species.
Our limited survey of potential habitats between the Florida panhandle
and Galveston, Texas, found abundant and apparently suitable habitat,
and confirmed seven new site records in 7 days (Salvato 2011, pp. 1-
28). In addition, there is a large extent of coastal estuarine habitats
along Texas, Louisiana, and Mississippi that have not been surveyed for
the presence of the Bay skipper. Existing programs have been developed
and implemented to conserve and restore the extensive estuarine wetland
network occupied by the Bay skipper.
Our review of the best available scientific and commercial
information revealed that the Bay skipper is poorly known and
additional research is needed to define range and abundance. However,
during our status review, we did not document any significant threats
to the species or its habitat throughout its currently known range, or
within a significant portion of that range; instead, with minimal
effort we increased the number of known populations (from 2 to 7), and
extended the range of the
[[Page 51964]]
species into the largest estuarine herbaceous marsh in the United
States. We found no evidence that the species has experienced
curtailment of range or habitat or is affected by disease or predation,
commercial or recreational harvest, the inadequacy of existing
regulations, or any other natural or manmade factor. We documented only
localized impacts from severe tropical storms and hurricanes; however,
the species' potential vulnerability to local extirpations that might
result from severe storms or any other stochastic event is offset by
the discovery of additional populations and a wider range for the Bay
skipper.
Based on our review of the best available scientific and commercial
information pertaining to the five factors, we find that the threats
are not of sufficient severity or intensity to indicate that the Bay
skipper is in danger of extinction (endangered), or likely to become
endangered within the foreseeable future (threatened), throughout all
or a significant portion of its range. Therefore, we find that listing
the Bay skipper as an endangered or threatened species is not warranted
throughout all of its range at this time.
Significant Portion of the Range
Having determined that the Bay skipper does not meet the definition
of an endangered or threatened species throughout its entire range, we
must next consider whether there are any significant portions of the
range where the Bay skipper is in danger of extinction or is likely to
become endangered in the foreseeable future. A portion of a species'
range is significant if it is part of the current range of the species
and it contributes substantially to the representation, resiliency, or
redundancy of the species. The contribution must be at a level such
that its loss would result in a decrease in the ability to conserve the
species.
In determining whether a species is an endangered or threatened
species in a significant portion of its range, we first identify any
portions of the range of the species that warrant further
consideration. The range of a species can theoretically be divided into
portions an infinite number of ways. However, there is no purpose to
analyzing portions of the range that are not reasonably likely to be
both (1) significant and (2) endangered or threatened. To identify only
those portions that warrant further consideration, we determine whether
there is substantial information indicating that: (1) The portions may
be significant, and (2) the species may be in danger of extinction
there or likely to become so within the foreseeable future. In
practice, a key part of this analysis is whether the threats are
geographically concentrated in some way. If the threats to the species
are essentially uniform throughout its range, no portion is likely to
warrant further consideration. Moreover, if any concentration of
threats applies only to portions of the species' range that are not
significant, such portions will not warrant further consideration.
If we identify portions that warrant further consideration, we then
determine whether the species is endangered or threatened in these
portions of its range. Depending on the biology of the species, its
range, and the threats it faces, the Service may address either the
significance question or the status question first. Thus, if the
Service considers significance first and determines that a portion of
the range is not significant, the Service need not determine whether
the species is an endangered or threatened species. Likewise, if the
Service considers status first and determines that the species is not
an endangered or threatened species in a portion of its range, the
Service need not determine if that portion is significant. However, if
the Service determines that both a portion of the range of a species is
significant and the species is an endangered or threatened species, the
Service will specify that portion of the range as an endangered or
threatened species under section 4(c)(1) of the Act.
The Bay skipper is highly restricted to estuarine habitats, and
threats to estuarine habitats are limited and localized throughout its
range. This species' small range suggests that stressors are likely to
affect it in a uniform manner throughout its range. However, we found
the stressors are not of sufficient intensity or severity or
geographically concentrated to warrant evaluating whether a portion of
the range is significant under the Act. Accordingly, our assessment
applies to the Bay skipper throughout its entire range.
We do not find that the Bay skipper is in danger of extinction now,
nor is it likely to become endangered within the foreseeable future
throughout all or a significant portion of its range. Therefore,
listing the Bay skipper as an endangered or threatened species under
the Act is not warranted at this time.
We request that you submit any new information concerning the
status of, or threats to, the Bay skipper to the Mississippi Ecological
Service's Fish and Wildlife Office (see ADDRESSES section) whenever it
becomes available. New information will help us monitor the Bay skipper
and encourage its conservation. If an emergency situation develops for
the Bay skipper or any other species, we will act to provide immediate
protection.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov at Docket No. FWS-R4-ES-2011-0012 and upon
request from the Mississippi Ecological Services Field Office (see FOR
FURTHER INFORMATION CONTACT).
Author
The primary author of this notice is the staff of the Mississippi
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: August 9, 2012.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-20820 Filed 8-27-12; 8:45 am]
BILLING CODE 4310-55-P