Federal Register, Volume 80 Issue 104 (Monday, June 1, 2015) 2015 Federal Register, 80 FR 30990-30996; Centralized Library: U.S. Fish and Wildlife Service -

[Federal Register Volume 80, Number 104 (Monday, June 1, 2015)]
[Proposed Rules]
[Pages 30990-30996]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-13136]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2015-0030; FF09E42000 156 FXES11130900000]

Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition To Remove the Bone Cave Harvestman (Texella reyesi) From the
List of Endangered and Threatened Wildlife

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding on a petition to remove the Bone Cave harvestman
(Texella reyesi) from the List of Endangered and Threatened Wildlife
under the Endangered Species Act of 1973, as amended (Act). Based on
our review, we find that the petition does not present substantial
scientific or commercial information indicating that the petitioned
action may be warranted. Therefore, we are not initiating a status
review in response to this petition. However, we ask the public to
submit to us any new information that becomes available concerning the
status of, or threats to, the Bone Cave harvestman or its habitat at
any time.

DATES: The finding announced in this document was made on June 1, 2015.

ADDRESSES: Copies of the petition are available in the docket
associated with this notice at http://www.regulations.gov and at http://fws.gov/southwest/es/austintexas/ or upon request from the Field
Supervisor of the Austin Ecological Services Field Office, 10711 Burnet
Road, Suite 200, Austin, TX 78758.

FOR FURTHER INFORMATION CONTACT: Adam Zerrenner, Field Supervisor,
Austin Ecological Services Field Office, 10711 Burnet Road, Suite 200,
Austin, TX 78758; by telephone at 512-490-0057; or by facsimile at 512-
490-0974. 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)(A) of the Act requires that we make a finding on
whether a petition to list, delist, or reclassify a species presents
substantial scientific or commercial information indicating that the
petitioned action may be warranted. We are to base this finding on
information provided in the petition, supporting information submitted
with the petition, and information otherwise available in our files. To
the maximum extent practicable, we are to make this finding within 90
days of our receipt of the petition and publish our notice of the
finding promptly in the Federal Register.
Our standard for substantial scientific or commercial information
within the Code of Federal Regulations (CFR) with regard to a 90-day
petition finding is ``that amount of information that would lead a
reasonable person to believe that the measure proposed in the petition
may be warranted'' (50 CFR 424.14(b)(1)). If we find that substantial
scientific or commercial information was presented, we are required to
promptly conduct a species status review, which we subsequently
summarize in a 12-month finding.

Petition History

On June 2, 2014, we received a petition from John Yearwood, Kathryn
Heidemann, Charles and Cheryl Shell, the Walter Sidney Shell Management
Trust, the American Stewards of Liberty, and Steven W. Carothers
requesting that we remove the endangered Bone Cave harvestman from the
Federal lists of endangered and threatened species. The petition
clearly identified itself as a petition and included the requisite
identification information for the petitioners, as required in 50 CFR
424.14(a). This finding addresses the petition.

Previous Federal Actions

The Bone Cave harvestman was originally listed as endangered on
September 16, 1988 (53 FR 36029). In an August 18, 1993, Federal
Register document (58 FR 43818), the Service gave the Bone Cave
harvestman protection under the Act as a separate species. It had
previously been listed as endangered as a part of the Bee Creek Cave
harvestman (Texella reddelli), which was subsequently re-classified
into two species, and this final rule set forth technical corrections
to ensure that the species continued to receive protection under the
Act. On March 14, 1994, we published a 90-day finding (59 FR 11755) on
a petition to delist the Bone Cave harvestman in which we found that
the petition did not present substantial scientific or commercial
information indicating that the petitioned action may have been
warranted. A draft recovery plan was available for public review and
comment on June 7, 1993, and a final recovery plan was published on
August 25, 1994 (Service 1994). On December 4, 2009, we completed a 5-
year review of the Bone Cave harvestman, which recommended that the
species remain listed as endangered (Service 2009).

Species Information

For information on the biology and life history of the Bone Cave
harvestman, see the final rule listing this species (53 FR 36029), the
Endangered Karst Invertebrates Recovery Plan for Travis and Williamson
Counties (Service 1994), and the 5-year Status Review for the Bone Cave
Harvestman (Service 2009), all posted at http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=J009. For
information on preserve design and management for karst invertebrate
species conservation, see the Karst Preserve Design Recommendations
(Service 2012) and the Karst Preserve Management and Monitoring
Recommendations (Service 2014) posted at http://www.fws.gov/southwest/es/AustinTexas/ESA_Sp_KarstInverts.html.

[[Page 30991]]

Evaluation of Information for This Finding

Under section 3(16) of the Act, we may consider for listing any
species, including subspecies, of fish, or wildlife, or plants, and any
distinct population segment (DPS) of any species of vertebrate fish or
wildlife that interbreeds when mature (16 U.S.C. 1532(16)). Such
entities are listed under the Act if we determine that they meet the
definition of an endangered or threatened species.
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations at 50 CFR 424 set forth the procedures for adding a species
to, or removing a species from, the lists of endangered and threatened
species. A species may be determined to be an endangered or threatened
species due to one or more of the five factors described in section
4(a)(1) of the Act:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
We must consider these same five factors in delisting a species. We
may delist a species according to 50 CFR 424.11(d) if the best
available scientific and commercial data indicate that the species is
neither endangered nor threatened for the following reasons:
(1) The species is extinct;
(2) the species is recovered; or
(3) the original data for classification were in error. According
to 50 CFR 424.11(d)(3), a species may be delisted when subsequent
investigations ``show that the best scientific and commercial data
available when the species was listed, or the interpretation of such
data, were in error.''
In making this 90-day finding, we evaluated whether the petition
presented substantial information indicating that the petitioned action
(delisting) may be warranted.
The petition did not assert that the Bone Cave harvestman is
extinct, nor do we have information in our files indicating that the
species is extinct.
The petition asserted that new information indicates that the
original data, or our interpretation of the data, used in the listing
of this species were in error. The petition also states that
significant conservation has been put in place since the species was
listed, such that the species is recovered.
In 2009, we conducted a 5-year status review of the Bone Cave
harvestman (Service 2009). The purpose of a 5-year status review is to
evaluate whether or not the species' status has changed since it was
listed (or since the most recent 5-year review). Based on a 5-year
review, we recommend whether the species should be removed from the
lists of endangered and threatened species, be changed in status from
endangered to threatened, or be changed in status from threatened to
endangered. As part of the 2009 Bone Cave harvestman review, we
evaluated whether the species had met the recovery criteria laid out in
the species' recovery plan (Service 1994, pp. 86-89).
Our recovery handbook (Service 2010) points out that recovery
criteria should address the biodiversity principles of resiliency,
redundancy, and representation (Schaffer and Stein 2000).
Resiliency is defined as the ability of a species to persist
through severe hardships or stochastic events (Tear et al. 2005, p.
841). A variety of factors contribute to a species' resiliency. These
can include how sensitive the species is to disturbances or stressors
in its environment, how often they reproduce and how many young they
have, and their specific habitat needs. A species' resiliency can also
be affected by the resiliency of individual populations and the number
of populations and their distribution across the landscape. Protecting
multiple populations and variation of a species across its range may
contribute to its resiliency, especially if some populations or
habitats are more susceptible or better adapted to certain threats than
others (Service and NOAA 2011, p. 76994). The ability of individuals
from populations to disperse and recolonize an area that has been
extirpated may also influence the species' resiliency. As population
size and habitat quality increase, the population's ability to persist
through periodic hardships also increases. Healthy populations are more
resilient and better able to withstand disturbances such as random
fluctuations in birth rates (demographic stochasticity), and variation
in rainfall and/or temperatures (environmental stochasticity).
Redundancy is defined as ensuring a sufficient number of
populations to provide a margin of safety to reduce the risk of losing
a species or certain representation (variation) within a species due to
catastrophic events or other threats. Redundancy is essential for long-
term viability (Shaffer and Stein 2000, pp. 307, 309-310; Groves et al.
2002, p. 506). This provides a margin of safety for a species to
withstand catastrophic events (Service and NOAA 2011, p. 76994) by
decreasing the chance of any one event affecting the entire species.
Redundancy is about spreading risk and can be measured through the
duplication and distribution of resilient populations across the range
of the species.
Representation is defined as conserving ``some of everything'' with
regard to genetic and ecological diversity to allow for future
adaptation and maintenance of evolutionary potential. Representation
and the adaptive capabilities (Service and NOAA 2011, p. 76994) of the
Bone Cave harvestman are also important for long-term viability.
Because a species' genetic makeup is shaped through natural selection
by the environments it has experienced (Shaffer and Stein 2000, p.
308), populations should be protected in the array of different
environments in which the invertebrate species occur as a strategy to
ensure genetic representation, adaptive capability, and conservation of
the species. Generally, the more representation, or diversity, the
species has, the more it is capable of adapting to changes (natural or
human caused) in its environment.
The recovery plan for the Bone Cave harvestman (Service 1994, pp.
86-88) identifies criteria for reclassification (from endangered to
threatened), but does not include delisting criteria because we were
uncertain about prospects for recovery and delisting of the species.
These recovery criteria are a way of measuring our progress toward
recovery. The recovery plan identifies two criteria for reclassifying
the species from endangered to threatened:
(1) Three karst fauna areas (if at least three exist) within each
karst fauna region in its range are protected in perpetuity. If fewer
than three karst fauna areas exist within a given karst fauna region,
then all karst fauna areas within that region should be protected.
(2) Criterion (1) has been maintained for at least 5 consecutive
years with assurances that these areas will remain protected in
perpetuity.
There are six karst fauna regions in Travis and Williamson Counties
that are known to contain the Bone Cave harvestman (Service 1994, p.
33): North Williamson, Georgetown, McNeil/Round Rock, Cedar Park,
Jollyville Plateau, and Central Austin. These regions are used as a way
to facilitate conservation of representation and redundancy (as defined
above) throughout the species' range.
For the purposes of the recovery plan, a karst fauna area ``is an
area known to

[[Page 30992]]

support one or more locations of a listed species and is distinct in
that it acts as a system that is separated from other karst fauna areas
by geologic and hydrologic features and/or processes that create
barriers to the movement of water, contaminants, and troglobitic
fauna'' that live their entire lives underground (Service 1994, p. 76).
Karst fauna areas should be far enough apart so that if a catastrophic
event (for example, contamination of the water supply, flooding,
disease) were to destroy one of the areas, that event would not likely
destroy any other area occupied by that species (Service 1994, p. 76).
To be considered ``protected,'' a karst fauna area must be
sufficiently large to maintain the integrity of the karst ecosystem on
which the species depends (Service 1994, p. 87). In addition, these
areas must also provide protection from threats such as red imported
fire ants, habitat destruction, and contaminants.
The overall recovery strategy for the Bone Cave harvestman includes
the perpetual protection and management of an adequate quantity and
quality of habitat (three karst fauna areas in each karst fauna
regions) that spans the species' geographic range and provides a high
probability of the species' recovery and survival over the long term.
Adequate quality (as discussed below) and quantity of habitat refers to
both size and number of preserved karst fauna areas that are sufficient
for supporting the karst invertebrates and the ecosystems upon which
they depend (Service 2011, p. 16). The recovery plan criteria call for
three karst fauna areas (preserves) in each karst fauna region. The
size of karst fauna area preserves should be large enough to ensure
resiliency as discussed above and to protect the environmental
integrity of the karst ecosystems upon which the species depends. The
number of karst fauna area preserves called for in the recovery
criteria provides redundancy for the species. A minimal level of
redundancy is essential to provide a margin of safety for the species
to reduce the risk of losing the species or representation (variation)
within the species from catastrophic events or other threats (Shaffer
and Stein 2000 pp. 307, 309-310, Groves et al. 2002, p. 506). The Bone
Cave harvestman has significant geographic variability across its
range, and loss of a significant number of locations in part of its
range could result in loss of genetic and ecological diversity. The
conservation of multiple karst fauna area preserves across the Bone
Cave harvestman's range should provide representation of the breadth of
its genetic and ecological diversity to conserve its adaptive
capabilities (Schaffer and Stein 2000, p. 308).
Adequate quality of habitat refers to (1) the condition and
configuration of preserved lands with respect to the known localities
for the species and (2) the ability of the species' needs to be met to
sustain viable populations. Due to the uncertainty in determining
population viability of the Bone Cave harvestman, the design of
preserves for its protection should be based on estimates and
assumptions that favor a high probability for recovery of this species
and the ecosystems upon which it depends as discussed below.
The Endangered Karst Invertebrates Recovery Plan for Travis and
Williamson Counties (Service 1994) calls for protecting karst fauna
areas sufficiently large to maintain the integrity of the karst
ecosystem on which the species depends. This focus on the ecosystem is
consistent with the purpose of the Act, which includes ``to provide a
means whereby the ecosystem upon which endangered species and
threatened species depend may be conserved.'' Therefore, we recommend
designing karst fauna area preserves to protect occupied karst
feature(s) and associated mesocaverns (humanly impassable voids). For
further guidance on how to provide for adequate quantity and quality of
habitat at specific invertebrate locations, we have developed and refer
to our Karst Preserve Design Recommendations (Service 2012).
According to our preserve design guidelines (Service 2012, p. 3-5),
karst fauna area preserves should include the following: (1) Surface
and subsurface drainage basins of at least one occupied cave or karst
feature; (2) a minimum of 16 to 40 hectares (ha) (40 to 100 acres (ac))
of contiguous, unfragmented, undisturbed land to maintain native plant
and animal communities around the feature and protect the subsurface
karst community; (3) 105-meter (m) (345-feet (ft)) radius undisturbed
area from each cave footprint for cave cricket foraging (cave crickets
are an important source of nutrient input to the karst ecosystem) and
to minimize deleterious edge effects; and (4) preserves should be free
of pipelines, storage tanks, or other facilities (for example, water
retention ponds) that could cause contamination.
In addition, due to the uncertainty in determining population
viability and habitat requirements of the Bone Cave harvestman, the
design of preserves for its protection should be based on estimates and
assumptions that favor a high probability for recovery of the species
and the ecosystems upon which it depends. This method follows a
precautionary approach, which provides guidance to avert irreversible
risk when facing uncertainty (Service 2012, p. A-1). The best available
scientific information indicates that this species cannot be
reintroduced into existing habitat. Life-history characteristics of
this species indicate that it requires stable temperature and humidity
(Barr 1968, p. 47, Mitchell 1971, p. 250) and suggest that this species
cannot be reintroduced because it cannot withstand surface climatic
conditions.
According to anecdotal reports provided to our field office,
limited efforts to maintain karst invertebrates in a lab setting have
been unsuccessful. Additionally, captive propagation techniques have
not been developed for karst invertebrates and may be challenging to
develop because of their specific adaptations to subterranean
environment. Further, the sample size that would likely be needed to
reintroduce a population into a new location cannot be obtained from
existing populations due to the cryptic nature of this species and the
fact that often only a few individuals are observed per cave survey.
Therefore, an attempt to re-establish a population after it has been
extirpated is not feasible at this time. In addition, if a preserve is
later found to be insufficient to support the species due to
surrounding developments being either too close or too dense, the
potential for adequately conserving the site is lost.
Because the Bone Cave harvestman has a relatively long life span
and low requirements for food, a decline in population size or even the
complete extirpation of the population due to the influence of
development or other threats may take years or even decades.
Observations of this species over several years on a preserve that is
too small for perpetual species preservation may not allow detection of
declines that are actually occurring. If these observations are used as
evidence that a preserve size was adequate, then the potential for
long-term preservation of the species may be lost due to irreversible
development surrounding the preserve. Therefore, preserve sizes should
be established with caution and be large enough to account for the
uncertainty in area requirements for a population.
According to the petition there are now more known occupied
locations identified; there were 6 confirmed caves at listing, 60
confirmed caves at the time the recovery plan was drafted, and 168
confirmed caves in 2009 when the 5-year status review was completed (53
FR 36029, Service 1994, 2009). The

[[Page 30993]]

petition also states that more locations are likely to be found. We
acknowledge there are more known locations since the time those
documents were completed and the increase is likely an increase in our
knowledge, not a true increase in the number of populations or range;
however, species are listed under the Act based on threats and not just
the number of sites or size of the range.
In addition, the petition states that 94 karst preserve areas are
currently providing significant conservation. However, many of the
existing protected areas referenced in the petition are too small to
meet our preserve design recommendations. As part of the 2009 5-year
status review of the Bone Cave harvestman, we reviewed the status of
all of the known locations of the harvestman (including 83 of the 94
mentioned in the petition) to assess whether the criteria from the
recovery plan to reclassify the species from endangered to threatened
had been met for the Bone Cave harvestman. We considered the habitat
size and condition to evaluate whether the locations could meet the
preserve design recommendations (a reflection of the potential to
support a resilient population) and then also looked at whether legally
binding mechanisms were in place to provide protection of these sites
over the long term (in perpetuity).
Of the locations known at the time of the 5-year review, 21 areas
appeared to have the ability to meet the preserve design criteria. Our
status review refers to 21 areas, while the petition indicates that the
status review considered 28 sites. This discrepancy is because the
petition considers each individual cave location, while our status
review considered closely located caves to be part of the same karst
fauna area. Of these 21 areas, 1 is no longer confirmed to have the
species (Barker Ranch Cave No. 1), and 5 are now protected karst fauna
areas (Priscilla's Well, Twin Springs, Cobbs Cavern, Karankawa, and
Tooth Cave).
In addition, at most of the remaining locations (of the 21 areas)
we are lacking information to confirm that they meet the preserve
design criteria (such as surface and subsurface drainage basins, tract
acreage, exact locations of the cave, and management activities to
protect against threats, such as red imported fire ants). Also, many of
these areas do not have a legally binding mechanism that ensures
perpetual protection and management. Hence, we are unsure whether those
areas have adequate undeveloped acreage, management, or protection
mechanisms to ensure the long-term protection and survival of the Bone
Cave harvestman.
Of the five protected karst fauna areas that meet preserve design
criteria, four occur in the North Williamson County Karst Fauna Region
and one occurs in the Jollyville Plateau Karst Fauna Region. However,
this species occurs in six karst fauna regions, and four of these have
no protected karst fauna areas that are confirmed to meet preserve
design recommendations. Therefore, the best available information
indicates that the criteria for reclassification from endangered to
threatened for this species have not been met, nor has adequate
representation and redundancy (three karst fauna areas in each karst
fauna region) been protected throughout the species' range, leaving the
species vulnerable to existing threats including habitat destruction.
The petition asserts that four additional locations are known since
the time of the 5-year review. However, the petition does not provide
adequate information that would support whether these four additional
locations are in a condition to meet preserve design recommendations.
Based on information in our files, we are aware of one additional cave
since the 5-year review that may meet preserve design recommendations
in the North Williamson Karst Fauna Region; however, it is privately
owned, and we are unsure about the property acreage and if the site
receives any type of protection or management. Regardless, the amount
of protected karst fauna area still falls short of the criteria for
reclassification from endangered to threatened.
Further, we reviewed 83 of the 94 caves identified in the petition
as receiving some level of protection in the 5-year review. Two of the
caves that we did not review (Cobbs Cavern and Whitney West Cave) are
now in confirmed karst fauna areas mentioned above (Cobbs Cavern and
Twin Springs), one (Pond Party Pit) is in the Beard Ranch Cave area
discussed in the 5-year review, and we have no locality information or
taxonomic verifications for the remaining caves and this information
was not provided in the petition.
The petition also asserts that threats to the species are not as
severe as originally thought. We evaluate that information, below, in
respect to the five listing factors.
Factor A: The present or threatened destruction, modification, or
curtailment of the species' habitat or range. In the 1988 listing rule
(53 FR 36029), we stated that the primary threat to the Bone Cave
harvestman was the potential loss of habitat due to development
activities, which could result in filling in or collapsing of caves;
alteration of drainage patterns; increase in flow of sediment,
pesticides, fertilizers, and urban run-off into caves; and increase in
human visitation and vandalism.
We also considered additional information on threats to the species
when we developed the recovery plan for the species (Service 1994, pp.
59-65) and when we conducted the 5-year status review of the species
(Service 2009, p. 2), in which we concluded that no change in the
species' status (that is, reclassification to threatened or delisting)
was warranted. We also reviewed available threat information in our
files and in a 1993 petition when we made our negative 90-day finding
on that petition to de-list (59 FR 11755).
The current petition asserts that ``Development activities on the
surface may not result in the significant loss or degradation of
habitat for T. reyesi as originally thought'' and suggests that
evidence of this is the species persistence in caves surrounded by
developed areas. Examples given in the petition are Inner Space
Caverns, Sun City caves, Weldon Cave, Three-Mile Cave, and Four-Mile
Cave. However, the observation of the species in these locations does
not mean their populations at these locations are thriving or can
withstand the long-term impacts from development activities that are
expected to occur to karst invertebrate populations in developed areas
as discussed in the listing rule, recovery plan, and 5-year status
review for the Bone Cave harvestman.
Bone Cave harvestman populations may be declining or threatened
even though they are still observed at a specific site. Information
adequate to detect population trends for this species is not readily
available and was not provided in the petition. This species has life-
history strategies that include characteristics such as low metabolic
and reproductive rates, long life spans, and inherently low sample
sizes, which make it difficult to detect population response to
possible impacts (Poulson and White 1969, p. 977, Howarth 1983, p.
374). We indicated in the 1994 90-day petition finding (59 FR 11755)
that more time was needed to detect if the species was declining;
however, while more time has passed, we are still lacking adequate data
to conduct a trend analysis at most locations, given that it can take
decades to detect population trends due to small sample sizes, the
difficulty surveying for the species, and their long life spans.

[[Page 30994]]

In addition, some of the threats from development are due to the
increased probability of chance events occurring in the future, such as
a contaminant event like a pipeline leak, which exists because more
contamination sources are in the vicinity of species' locations due to
development.
The petition states that several Sun City caves are examples of
areas where the species can persist in developed areas. However, the
petition failed to provide data adequate to assess trends in the karst
invertebrate populations since the development occurred. In addition,
we worked with the Sun City developers when they designed the project
to develop strategies that we believed at the time would avoid or
minimize the possibility of ``take'' to listed karst species. While we
now believe that most of the Sun City cave preserves are too small to
meet our preserve design recommendations for recovery and long-term
survival (Service 2012), we expect that the strategies and measures put
in place likely have reduced the rate of impacts to the species.
The commercial cave known as Inner Space Caverns is another example
the petition provided where the Bone Cave harvestman continues to
persist in a developed area. Although the Bone Cave harvestman may be
present at Inner Space Caverns, this does not ensure their populations
are robust and secure; they may still be declining, and are at risk due
to competition with surface-dwelling invertebrates and other threats
associated with development such as the potential for contamination.
This cave has an overgrowth of blue-green algae growing near cave
lights where the petition states that this species has been observed.
This type of algae is known as ``lampenflora'' and favors surface-
dwelling invertebrate species that can out-compete karst invertebrate
species (Mulec and Kosi 2009, p. 109, Culver 1986, p. 438), such as the
Bone Cave harvestman. The petition failed to provide any data adequate
to assess trends in the karst invertebrate population in relation to
the time (duration and frequency) that they have been exposed to the
artificial lighting. Additionally, part of the cave footprint occurs
under a major interstate highway and train tracks, which both present a
threat of a contaminant spill that could impact the species in the
future.
Weldon Cave was another example in the petition of a cave occupied
by the Bone Cave harvestman within a developed area. Based on the best
available information in our files this cave is surrounded by
undeveloped open space. Other than a small portion of the subsurface
drainage basin potentially being impacted by a school campus, this cave
appears to meet our preserve design recommendations but is not within a
developed area, as asserted in the petition. Three-Mile Cave and Four-
Mile Cave were also provided in the petition as examples of developed
caves wherein the Bone Cave harvestman is known to occur. According to
the petition, surveys conducted by SWCA in 2008 and 2009 documented the
Bone Cave harvestman at these locations. However, detailed survey data
were not provided by the petitioners and were not in the SWCA 2009
``Annual Report of Activities Involving Endangered Karst Invertebrates
under Threatened and Endangered Species Permit TE800611-2.''
The petition also states that, since the Bone Cave harvestman uses
mesocaverns, it is protected from surface development activities
because mesocaverns are ``geologically protected.'' We are unclear why
the petition contends that mesocaverns are protected because
mesocaverns are subject to rapid permeation of surface water (Cowan et
al. 2007, p. 160), and karst landscapes (including mesocaverns) are
particularly susceptible to groundwater contamination because water
penetrates rapidly through bedrock conduits providing little or no
filtration (White 1988, p. 149).
One of the major threats to the Bone Cave harvestman is habitat
loss due to increasing urbanization. The Bone Cave harvestman is a
troglobite, meaning it lives its entire life underground. Karst
ecosystems are heavily reliant on surface plant and animal communities
for nutrient input.
Caves in central Texas that are occupied by federally listed karst
invertebrates, such as the Bone Cave harvestman, receive energy (or
nutrients) primarily from (1) detritus (decomposing organic matter)
that falls or is washed into the caves and (2) energy brought into the
caves by cave crickets (Ceuthophilus spp.) (Barr 1968, p. 48; Reddell
1993, p. 2; Lavoie et al. 2007, p. 114; Taylor 2003, p. 3, 2004, p. 2,
2005, p. 97), which are found in most Texas caves (Reddell 1966, p.
33). Cave crickets forage widely in the surface habitat surrounding the
cave. Karst invertebrates feed on the cave cricket eggs (Mitchell 1971,
p. 251), feces (Barr 1968, pp. 51-53, Poulson et al. 1995, p. 226), and
directly on the crickets themselves (Elliott 1994, p. 15).
Development within urbanized areas can destroy or alter the surface
plant and animal communities on which karst invertebrates depend. As
development increases within the cave crickets' foraging area, there
may be dramatic shifts in the available food supply within the cave
(Taylor et al. 2007, p. 7). The leaf litter and other decomposing
material that make up most of the detritus from the surface plant and
animal community may also be reduced or altered, resulting in a
reduction of nutrient and energy flow into the cave. A study by Taylor
et al. (2007) compared caves in urbanized areas that were impacted by
development to those in natural areas and found that, even though a
small area within a largely urbanized ecosystem may support a cave
community where karst invertebrates are occasionally seen, these
populations are significantly lower than those found in caves in more
natural, less developed ecosystems, most likely as a result of reduced
nutrient input. Another study at Lakeline Cave in Travis County, Texas,
was conducted in association with the issuance of a habitat
conservation plan and accompanying section 10(a)(1)(B) permit issued
for Lakeline Mall. That study is based on data collected from 1992
through 2011, and it documented a significant decline during that 20-
year timeframe in another endangered karst invertebrate, Rhadine
persephone, and cave crickets as development increased (ZARA 2012, pp.
8, 10, 12). Further, at Lakeline Mall Cave, no more than three Bone
Cave harvestmen have been observed during any single survey (ZARA 2012,
p. 11). Also, no Bone Cave harvestmen were seen during 6 years (1993,
1999, 2001, 2006, 2009, and 2010) and 12 surveys in Lakeline Mall Cave
(ZARA 2012, p. 11).
Available information in our files supports our projection in the
1988 listing rule that development and human population would continue
to increase within the range of the species. The population of the City
of Austin grew from 251,808 people in 1970 to 735,088 people in 2007
(City of Austin 2007). This represents a 192-percent increase over the
37-year period. Population projections from the Texas State Data Center
(2012, pp. 496-497), estimate that Travis County will increase 94
percent in population from 1,024,266 in 2010, to 1,990,820 in 2050. The
Texas State Data Center also estimates an increase in human population
in Williamson County from 422,679 in 2010, to 2,015,294 in 2050
representing a 377-percent increase over a 40-year timeframe. All human
population projections from the Texas State Data Center presented here
are under a high-growth scenario, which

[[Page 30995]]

assumes that migration rates from 2000 to 2010 will continue through
2050 (Texas State Data Center and the Office of the State Demographer
2012, p. 9). Urbanization and human population growth and development
were identified as a threat in the original 1988 listing rule and
continue to represent a threat to the species.
Factor B: Overutilization for commercial, recreational, scientific,
or educational purposes. In the 1988 listing rule for the Bone Cave
harvestman, we did not identify any threats under this factor.
Likewise, the petition and our review of the information in our files
did not identify any threats under this factor.
Factor C: Disease or predation. In the 1988 listing rule, we stated
that increased human population increases the threat of predation by
and competition with exotic (non-native) and native surface-dwelling
species, such as sow bugs, cockroaches, and red imported fire ants. The
petition states that ``Recent studies suggest that fire ants may not
present as significant or as lasting of a threat to the species as
originally believed.'' The information cited regarding red imported
fire ants is identified in the petition as an article by Porter and
Savignano (1990), which we previously considered in our finding on the
1993 petition, and another study by Morrison (2002). The petition
states that ``a subsequent study by Morrison in 2002 revisited the
Porter and Savignano (1990) study area 12 years later and replicated
their study.
Morrison (2002, pp. 2341, 2343-2344) found that arthropod
communities had rebounded to pre-RIFA [red imported fire ant]-invasion
levels and that all measures of native ant and other arthropod species'
diversity had returned to pre-invasion levels. Red imported fire ants
were still the most abundant ant species, but not nearly as abundant as
during the initial red imported fire ants infestation. He concluded
that the impacts to arthropod communities by red imported fire ants
might be greatest during and shortly after the initial invasion, but
long-term impacts are likely not as significant as once believed.
However, we note that Morrison (2002, p. 2342) also states that ``it is
quite likely that red imported fire ants did contribute directly or
indirectly to the disappearance or reduction in numbers of species''
and that their study ``should not be interpreted as an indication that
detrimental effects of invasive ants will simply disappear with time.''
In addition, this is not ``new information'' as we have already
reviewed these articles and considered the information they provided in
the Bexar County Karst Invertebrates Recovery Plan (Service 2011, p.
12) and in our Karst Preserve Management and Monitoring Recommendations
(Service 2014, p. 3), which is applicable here as all central Texas
endangered karst invertebrates have similar life-history
characteristics, and one of the Bexar County invertebrates is in the
same genus (Texella) as the Bone Cave harvestman. In addition, red
imported fire ants have been found within and near many caves in
central Texas and have been observed feeding on dead troglobites, cave
crickets, and other species within caves (Elliott 1992, p. 13, 1994, p.
15, 2000, pp. 668, 768; Reddell 1993, p. 10; Taylor et al. 2003, p. 3).
Factor D: The inadequacy of existing regulatory mechanisms. The
1988 listing rule states that ``there are currently no laws that
protect any of these species or that indirectly address protection of
their habitat.''
While the petition did discuss some new ordinances that appear to
have been put in place since the time of listing, we do not have enough
information to indicate whether or not these State and local ordinances
provide enough protection from all threats to the Bone Cave harvestman.
The petition states that ``the regulatory landscape includes a
number of measures contributing to the conservation of the species
outside of the protections afforded by the Endangered Species Act of
1973, as amended.'' For example, they say that protections offered
though the City of Austin are adequate to protect the species in
Austin, Texas. In the course of our work, we have reviewed these
regulations and understand that most caves that are defined by the City
of Austin's Environmental Criteria Manual as a cave are provided a 46-
to 91-m (150- to 300-ft) set-back area (City of Austin 2014, p. 13-3).
However, a 46-m (150-ft) or 91-m (300-ft) set-back is not adequate to
meet our preserve design criteria, does not protect the cave cricket
foraging area, and potentially does not include the surface and
subsurface drainage basins. Further, it is not applicable across the
range of the Bone Cave harvestman because the species occurs in Travis
and Williamson Counties and the City of Austin does not cover all of
those counties.
The petition states that the City of Georgetown Water Quality
Management Plan for the Georgetown salamander will offer protection to
the Bone Cave harvestman. They state that this plan encourages the use
of best management practices to protect water quality at Georgetown
salamander locations. However, there are few Bone Cave harvestman
locations that occur near Georgetown salamander locations, so any
protection offered to the harvestman would be limited. Further, it is
not clear from the petition whether this mechanism is voluntary or if
it is regulatory or if it is currently in effect. In addition, the
petition did not provide enough detail for us to evaluate all benefits
this plan would provide to the Bone Cave harvestman, and it appears
that participation in this plan is at least in part voluntary.
The petition states that the Texas Commission on Environmental
Quality (TCEQ) Edwards Rules provide protection to recharge features on
the Edwards Plateau and that this provides protection from pollution to
the Bone Cave harvestman. In a discussion of Factor D in the Bexar
County Karst Invertebrates Recovery Plan (Service 2011, p. 13), we
state that ``the TCEQ water quality regulations do not provide much
protection to the species' habitat (see 65 FR 81419-81433 for more
information). For example, while some TCEQ practices provide protection
from water quality impacts, others, such as sealing cave entrances for
water quality reasons, can harm karst invertebrates.'' Sealing cave
entrances can be harmful by blocking off water (leading to drying) and
nutrient input to the karst invertebrate habitat. In addition, not all
of the caves and mesocaverns that the Bone Cave harvestman occurs in
are considered recharge features and, therefore, would not receive some
of the water quality protection measures. Also, not all locations of
the Bone Cave harvestman are under the jurisdiction of the Edwards
Rules.
Factor E: Other natural or manmade factors affecting the continued
existence of the species. In the 1988 listing rule, we stated that this
species is extremely vulnerable to losses because of its severely
limited range and because of its naturally limited ability to colonize
new habitats. We also stated that the very small size of the species
habitat units and the fragile nature of cave ecosystems make them
vulnerable to even isolated acts of vandalism. The petition states,
``Inner Space Cavern demonstrates that the species can persist in caves
with frequent human visitation and may be more tolerant of related
habitat modification than originally believed.'' They also provide
Three-Mile Cave and Four-Mile Cave as examples of caves that have
experienced human use yet the species persists. The petition contends
that, since the Bone Cave harvestman exists in Inner Space Caverns,
human visitation is not a threat. The petition also states that Three-
mile and Four-mile Cave had

[[Page 30996]]

graffiti from the 1890s, 1920s, and 1950s. Yet, no detailed information
was provided to demonstrate if these caves experienced continued human
use. The petition also indicates that Four-Mile Cave was inaccessible
to humans prior to 2009 due to boulders blocking the entrance. In
addition, the petition provided no trend analysis for these caves. As
stated earlier, the observation of the species in these locations does
not mean the populations at these locations have not been impacted (in
a way that is short of extirpation) or can withstand the long-term
impacts that are expected to occur to karst invertebrate populations in
developed areas or from human visitation.
In the species 5-year status review (Service 2009, p. 18) we said,
``Although climate change was not identified as a threat to T. reyesi
in the original listing document or in the recovery plan, the species'
dependence on stable temperatures and humidity levels opens the
possibility of climatic change impacting this species. Therefore, while
it appears reasonable to assume that T. reyesi may be affected, we lack
sufficient certainty to know how climate change will affect this
species.''
The petitioners state that ``the use of small voids or
`mesocaverns' within the geologic formations known to support occupied
caves mitigates the potential threat of climate change.'' We
acknowledge that mesocaverns may provide some protection from
fluctuations in temperature and humidity that may be induced by climate
change. However, the presence of mesocaverns alone will likely not be
sufficient to ameliorate all of the effects that climate change may
pose to this species. Karst invertebrates depend on stable temperatures
and high humidity (Barr 1968, p. 47, Mitchell 1971, p. 250). The
temperatures in caves are typically the average annual temperature of
the surface habitat and vary much less than the surface environment
(Howarth 1983, p. 372, Dunlap 1995, p. 76). If average surface
temperatures increase, this could result in increased in-cave
temperatures, which could affect the Bone Cave harvestman.
Increased and/or more severe storms as well as prolonged periods of
high temperatures and drought between rainfall events associated with
predicted climate change effects may also impact the cave environment.
Changes in rainfall regimes may affect the harvestman in several ways,
including directly either through flooding or indirectly by modifying
their habitat or nutrient availability. Changes in rainfall regimes
could (1) alter the moisture levels within the caves leaving them drier
between floods, which could lead to desiccation of the Bone Cave
harvestman and (2) affect the amount and timing of nutrients washed
into a cave, potentially resulting in longer periods between nutrient
input. These changes to drier and less suitable conditions in the caves
will likely cause the Bone Cave harvestman to retreat farther into
mesocaverns and away from nutrients that are thought to be located in
larger cave passages (Howarth 1987, pp. 5-7), causing individuals to
spend more energy trying to acquire nutrients in an already stressed
environment. In addition, caves in arid regions have been shown to have
smaller invertebrate populations and diversity due to less moisture and
nutrient availability (George Veni, National Cave and Karst Research
Institute, pers. comm. 2010). Since the Bone Cave harvestman is also
sensitive to these habitat parameters, it is reasonable to predict that
climate change could affect its populations in a similar manner despite
the presence of mesocaverns.
Further, stochastic (random) events from either environmental
factors (for example, severe weather) or demographic factors (which
come from the chance events of birth and death of individuals)
exacerbate threats to the species because of its small population size
(Melbourne and Hastings 2008, p. 100). The risk of extinction for any
species is known to be highly inversely correlated with population size
(Pimm et al. 1988, pp. 774-775, O'Grady et al. 2004, pp. 516, 518). In
other words, the smaller the population the greater the overall risk of
extinction. Therefore, threats to the Bone Cave harvestman are
exacerbated by its small population size, which makes it more
vulnerable to existing threats.

Finding

We have reviewed the petition and also evaluated readily available,
related information in our files. The petitioners have based their
assessment that the species can thrive in developed areas on
information that we have already reviewed (except in 4 caves discovered
since the 5-year status review and 7 for which we lack locality
information or taxonomic verifications) while working on previous
documents (Service 2009, 2012) or on observations that lack a large
enough sample size to produce population trend information for the Bone
Cave harvestman. The petition provided no trend analysis to indicate
that this species can withstand the threats associated with development
or climate change over the long term. Based on our review and
evaluation, we find that the petition does not present substantial
scientific or commercial information indicating that delisting of the
Bone Cave harvestman may be warranted due to recovery, extinction, or
error in the original scientific data at the time the species was
classified or in our interpretation of the data. However, much progress
has been made toward recovery in the North Williamson and Jollyville
Plateau Karst Fauna Regions. We encourage interested parties to
continue to gather data and implement conservation actions across the
range of the Bone Cave harvestman that will further assist with the
conservation of this species. If you wish to provide information
regarding the Bone Cave harvestman, you may submit your information or
materials to the Field Supervisor, Austin Ecological Services Field
Office (see ADDRESSES) at any time.

References Cited

A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Austin Ecological
Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Authors

The primary authors of this notice are staff members of the Austin
Ecological Services Office.

Authority

The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).

Dated: May 21, 2015.
Gary Frazer,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-13136 Filed 5-29-15; 8:45 am]
BILLING CODE 4310-55-P