[Federal Register: September 18, 2008 (Volume 73, Number 182)]
[Proposed Rules]
[Page 54125-54132]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18se08-30]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R4-ES-2008-0082; 92210750083-B2]
RIN 1018-AU85
Endangered and Threatened Wildlife and Plants; Proposed
Endangered Status for Reticulated Flatwoods Salamander; Proposed
Designation of Critical Habitat for Frosted Flatwoods Salamander and
Reticulated Flatwoods Salamander
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule; supplemental information.
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[[Page 54126]]
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are
providing supplemental information on the proposal to split the listing
under the Endangered Species Act of 1973, as amended (Act), of the
currently threatened flatwoods salamander (Ambystoma cingulatum) into
two distinct species: frosted flatwoods salamander (Ambystoma
cingulatum) and reticulated flatwoods salamander (Ambystoma bishopi)
due to a change in taxonomy. The frosted flatwoods salamander will
maintain the status of threatened, and contained in this document is
the threats analysis under section 4(a)(1) of the Act which explains
this determination. We are accepting public comments from all
interested parties on the proposed rule (73 FR 47258, August 13, 2008),
the associated draft economic analysis, the listing status of both
species, and the supplemental information we are providing in this
document. If you submitted comments previously, then you do not need to
resubmit them because we have already incorporated them into the public
record and we will fully consider them in preparation of our final
determination.
DATES: We will accept comments received on or before October 14, 2008.
ADDRESSES: You may submit comments by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the instructions for submitting comments.
U.S. mail or hand-delivery: Public Comments Processing,
Attn: RIN 1018-AU85; Division of Policy and Directives Management; U.S.
Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington,
VA 22203.
We will not accept e-mail or faxes. We will post all comments on
http://www.regulations.gov. This generally means that we will post any
personal information you provide us (see the Public Comments section
below for more information).
FOR FURTHER INFORMATION CONTACT: Ray Aycock, Field Supervisor, U.S.
Fish and Wildlife Service, Mississippi Field Office, 6578 Dogwood View
Parkway, Jackson, MS 39213; telephone: 601-321-1122; facsimile: 601-
965-4340. If you use a telecommunications device for the deaf (TDD),
call the Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Public Comments
We will accept written comments and information we receive on our
before the date listed in the DATES section on our proposed critical
habitat designation, proposed endangered status for reticulated
flatwoods salamander, the draft economic analysis published in the
Federal Register on August 13, 2008 (73 FR 47258), and proposed
threatened status for frosted flatwoods salamander (as presented in
this document). We will consider information and recommendations from
all interested parties. Regarding the supplemental information we
present in this document, we are particularly interested in comments
concerning:
(1) Any available information on known or suspected threats and
proposed or ongoing development projects with the potential to threaten
either the frosted flatwoods salamander or the reticulated flatwoods
salamander or any information on the need to change the status of
either species, or
(2) The effects of potential threat factors that are the basis for
a listing determination under section 4(a) of the Act, which are:
(a) Present or threatened destruction, modification, or curtailment
of the species' habitat or range;
(b) Overutilization for commercial, recreational, scientific, or
educational purposes;
(c) Disease or predation;
(d) The inadequacy of existing regulatory mechanisms; or
(e) Other natural or manmade factors affecting its continued
existence.
You may submit your comments and materials by one of the methods
listed in the ADDRESSES section. We will not accept comments you send
by e-mail or fax or to an address not listed in the ADDRESSES section.
We will post your entire comment--including your personal
identifying information--on http://www.regulations.gov. If you provide
personal identifying information, you may request at the top of your
document that we withhold this information from public review. However,
we cannot guarantee that we will be able to do so.
Comments and materials we receive, as well as supporting
documentation we used in preparing the proposed rule and draft economic
analysis, will be available for public inspection on http://
www.regulations.gov, or by appointment, during normal business hours,
at the U.S. Fish and Wildlife Service, Mississippi Field Office (see
FOR FURTHER INFORMATION CONTACT).
Background
It is our intent to discuss only those topics directly relevant to
the analysis of the five listing factors affecting the frosted
flatwoods salamander. For more information on the flatwoods salamander,
refer to the final listing rule published in the Federal Register on
April 1, 1999 (64 FR 15691) and the proposed designation of critical
habitat published in the Federal Register on August 13, 2008 (73 FR
47258).
Listing of the Frosted Flatwoods Salamander
History of the Action
The final rule to list the flatwoods salamander (Ambystoma
cingulatum) as threatened was published on April 1, 1999 (64 FR 15691).
On August 13, 2008, we published a proposed rule to split the species
into two distinct species: frosted flatwoods salamander (Ambystoma
cingulatum) and reticulated flatwoods salamander (Ambystoma bishopi)
due to new taxonomic information (73 FR 47258). In that proposed rule,
we provided the analysis of the threats for the reticulated flatwoods
salamander and our determination of its endangered status. In this
document, we are publishing our analysis and determination to retain
threatened status for the frosted flatwoods salamander.
Species Information
Taxonomic revision resulting from research done by Pauly et al.
(2007, pp. 415-429) split the flatwoods salamander into two species--
the frosted flatwoods salamander and the reticulated flatwoods
salamander. Based on the best available information, the life-history
traits and habitat use of both the frosted flatwoods salamander and the
reticulated flatwoods salamander are similar to those previously
described for the flatwoods salamander (64 FR 15691, April 1, 1999; 73
FR 47258, August 13, 2008). However, most of our references predate
Pauly et al. (2007) and, therefore, do not distinguish between the two
species.
Both species of flatwoods salamanders are moderately sized
salamanders that are generally black to chocolate-black with fine,
irregular, light gray lines and specks that form a cross-banded pattern
across their backs (back pattern more net-like in the reticulated
flatwoods salamander). The frosted flatwoods salamander generally tends
to be larger than the reticulated flatwoods salamander. Adults are
terrestrial and live underground most of the year. They breed in
relatively small, isolated ephemeral ponds where the larvae develop
until metamorphosis. Post-metamorphic salamanders migrate out of the
ponds and into the uplands where they live until they move back to
ponds to breed as adults.
Flatwoods salamanders are endemic to the lower southeastern Coastal
Plain and occur in what were historically
[[Page 54127]]
longleaf pine-wiregrass flatwoods and savannas. The historical range of
what is now considered the frosted flatwoods salamander included parts
of the States of Florida, Georgia, and South Carolina. This area
encompassed the lower Coastal Plain of the southeastern United States
along the Gulf Coast east of the Apalachicola-Flint Rivers, across
north Florida, south into north-central Florida, and north along the
Atlantic Coast through coastal Georgia and South Carolina.
We have compiled 84 historical (pre-1990) records for the frosted
flatwoods salamander. Twenty historical records (with supporting
locality information) for the frosted flatwoods salamander are known
from eight counties in Florida. Frosted flatwoods salamander breeding
has been documented at only four (20 percent) of these sites since
1990. Surveys conducted since 1990 by Federal and State agency
personnel, as well as private parties, have resulted in the
identification of more than 50 additional frosted flatwoods salamander
breeding sites, including two sites in Jefferson County, a county that
previously was not known to be occupied by the salamander. Most of
these new breeding sites are located on the Apalachicola and Osceola
National Forests, and on St. Marks National Wildlife Refuge. Sixteen
populations of the frosted flatwoods salamander are known from Baker,
Franklin, Jefferson, Liberty, and Wakulla Counties in Florida.
Thirty-four historical records for the frosted flatwoods salamander
are known from 20 counties in Georgia. Frosted flatwoods salamanders
have not been seen again at any of these sites in recent years;
however, surveys conducted since 1990 have resulted in the discovery of
23 new breeding sites. All but one of these new sites are located on
the Fort Stewart Military Installation. The one additional pond was
discovered on the Townsend Bombing Range. Currently, these breeding
sites support six frosted flatwoods salamander populations in Bryan,
Evans, Liberty, and McIntosh Counties, Georgia, all on Department of
Defense lands. The frosted flatwoods salamander is assumed extirpated
from 16 other counties in Georgia where it previously occurred.
However, some appropriate habitat still remains on the Okefenokee
National Wildlife Refuge and the potential may exist for the species to
occur there.
Thirty historical records for the frosted flatwoods salamander are
known from five counties in South Carolina. Since 1990, metamorphic
frosted flatwoods salamanders have been documented at six (21 percent)
of these sites, and one new breeding site has been discovered.
Currently, four populations of the frosted flatwoods salamander are
known from Berkeley, Charleston, and Jasper Counties in South Carolina.
Two populations are on private land in Jasper County: one population
occurs on the Francis Marion National Forest in Berkeley County, and
one population occurs on the Santee Coastal Preserve (state-owned and -
managed) in Charleston County.
The combined data from all survey work completed since 1990 in
Florida, Georgia, and South Carolina indicate there are 26 populations
of the frosted flatwoods salamander. Some of these populations are
inferred from the capture of a single individual. Twenty-three (88
percent) of the known frosted flatwoods salamander populations occur
primarily on public land. Sixteen of the populations (62 percent of
total populations of the species) on public land represent
metapopulations supported by more than one breeding site. A single
population occurs on each of the following publicly owned sites: Tate's
Hell State Forest and Osceola National Forest in Florida; Townsend
Bombing Range in Georgia; and Francis Marion National Forest and Santee
Coastal Reserve in South Carolina. In Florida, habitat on Apalachicola
National Forest supports 10 populations and on St. Marks National
Wildlife Refuge supports 2 populations. In Georgia, five populations
occur on Fort Stewart Military Installation. Three (12 percent) frosted
flatwoods salamander populations are solely on private land.
Summary of Factors Affecting the Species (Frosted Flatwoods Salamander)
Section 4 of the Act (16 U.S.C. 1531 et seq.) and regulations (50
CFR part 424) promulgated to implement the listing provisions of the
Act set forth the procedures for adding species to the Federal Lists of
Endangered and Threatened Wildlife and Plants. A species may be
determined to be endangered or threatened due to one or more of the
five factors described in section 4(a)(1) of the Act. The original
listing rule for the flatwoods salamander (64 FR 15691; April 1, 1999)
contained a discussion of these five factors. Only those factors
relevant to the frosted flatwoods salamander (Ambystoma cingulatum
Cope, 1867) are described below:
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
The major historical threat to the frosted flatwoods salamander was
loss of both its longleaf pine-slash pine flatwoods terrestrial habitat
and its isolated, seasonally ponded breeding habitat. The combined pine
flatwoods (longleaf pine-wiregrass flatwoods and slash pine flatwoods)
historical area was approximately 32 million acres (ac) (12.8 million
hectares (ha)) (Outcalt 1997, p. 4). This area has been reduced to 5.6
million ac (2.27 million ha) or approximately 18 percent of its
original extent (Outcalt 1997, p. 4). These remaining pine flatwoods
(non-plantation forests) areas are typically fragmented, degraded,
second-growth forests (Outcalt 1997, p. 6). Conversion of pine
flatwoods to intensively managed (use of heavy mechanical site
preparation, high stocking rates, low fire frequencies) slash or
loblolly plantations often resulted in degradation of flatwoods
salamander habitat by creating well-shaded, closed-canopied forests
with an understory dominated by shrubs or pine needles (Outcalt 1997,
pp. 4-6; Palis 1997, pp. 61-63). Disturbance-sensitive groundcover
species, such as wiregrass (Aristida stricta [= A. beyrichiana] Kesler
et al.2003, p. 9), dropseed (Sporobolus spp.), and perennial forbs were
either greatly reduced in extent or were replaced by weedy pioneering
species (Moore et al.1982, p. 216; Outcalt and Lewis 1988, pp. 1-12;
Hardin and White 1989, pp. 243-244). Flatwoods salamanders are unlikely
to persist in uplands with a disturbed, wiregrass-depauperate
groundcover (Palis 1997, p. 63).
Degradation of the remaining frosted flatwoods salamander habitat
is a current, ongoing threat. Forest management that includes intensive
site preparation may adversely affect flatwoods salamanders directly
and indirectly (Means et al. 1996, p. 426). Bedding (a technique in
which a small ridge of surface soil is elevated as a planting bed)
alters the surface soil layers, disrupts the site hydrology, and often
eliminates the native herbaceous groundcover. This can have a cascading
effect of reducing the invertebrate community that serves as a food
source for flatwoods salamander adults. Post-larval and adult flatwoods
salamanders occupy upland flatwoods sites where they live underground
in crayfish burrows, root channels, or burrows of their own making
(Goin 1950, p. 311; Neill 1951, p. 765; Mount 1975, pp. 98-99; Ashton
and Ashton 2005, pp. 63, 65,
[[Page 54128]]
68-71). The occurrence of these underground habitats is dependent upon
protection of the soil structure. Intensive site preparation destroys
the subterranean voids and may result in entombing, injuring, or
crushing individuals.
Ecologists consider fire suppression the primary reason for the
degradation of remaining longleaf pine forest habitat. The disruption
of the natural fire cycle has resulted in an increase in slash and
loblolly pine on sites formerly dominated by longleaf pine, an increase
in hardwood understory, and a decrease in herbaceous ground cover
(Wolfe et al. 1988, p. 132). Although frosted flatwoods salamanders
have been found at sites with predominately loblolly or slash pine, the
long-term viability of populations at these sites is unknown. In
addition, ponds surrounded by pine plantations and protected from the
natural fire regime may become unsuitable as frosted flatwoods
salamander breeding sites due to canopy closure and the resultant
reduction in emergent herbaceous vegetation needed for egg deposition
and larval development sites (Palis 1997, p. 62). Lack of fire may
result in the development of a thick shrub zone, making it physically
difficult or impossible for adult salamanders to enter the breeding
ponds (Ripley and Printiss 2005, pp. 1-2, 11).
Alterations of the longleaf pine ecosystem, as a result of
incompatible forest practices, have caused the historic loss of most of
the original frosted flatwoods salamander habitat. Although conversion
of native pine flatwoods to plantation forests is not considered a
significant threat at this time, most of the historic extirpation of
frosted flatwoods populations in Florida, Georgia, and South Carolina
over the last six decades resulted from habitat degradation on lands
managed for timber extraction.
Land use conversions to housing, other development projects, and
agriculture eliminated large areas of pine flatwoods in the past
(Schultz 1983, pp. 24-47; Stout and Marion 1993, pp. 422-429; Outcalt
and Sheffield 1996, pp. 1-5; Outcalt 1997, pp. 1-6). Residential
development and conversion to agriculture have resulted in the
historical loss of one frosted flatwoods salamander population each
from Ben Hill, Berrien, Brooks, Effingham, Emanuel, and Irwin Counties,
Georgia (Seyle 1994, pp. 4-5); an additional site has been degraded in
Orangeburg County, South Carolina, and is not currently occupied
(LaClaire 1995). State forest inventories completed between 1989 and
1995 indicated that flatwoods losses through land use conversion were
still occurring (Outcalt 1997, pp. 3-6); however further conversions
are likely to impact only the three populations that remain on private
lands.
In addition to the loss of upland forested habitat, the number and
diversity of small wetlands where frosted flatwoods salamanders breed
have been substantially reduced. Threats to breeding sites include
alterations in hydrology, agricultural and urban development, road
construction, incompatible silvicultural practices, shrub encroachment,
dumping in or filling of ponds, conversion of wetlands to fish ponds,
domestic animal grazing, soil disturbance, and fire suppression
(Vickers et al. 1985, pp. 22-26; Palis 1997, p. 58; Ashton and Ashton
2005, p. 72). Hydrological alterations, such as those resulting from
ditches created to drain flatwoods sites or fire breaks and plow lines,
represent one of the most serious threats to frosted flatwoods
salamander breeding sites. Lowered water levels and shortened
hydroperiods at these sites may prevent successful flatwoods salamander
recruitment because larval salamanders require 11 to 18 weeks to reach
metamorphosis and leave the ponds (Palis 1995, p. 352).
U.S. Geological Survey has documented multiple drought periods in
the southeastern United States since the 1890s (USGS Open File Report
00-380, p. 1). Among significant periods documented in the last three
decades are: 1980-1982, 1984-1988, 1998-2000 (USGS Water Supply Paper
2375), and currently from 2006-2008. Although drought is a naturally
occurring condition, it presents additional complications for a species
like the frosted flatwoods salamander, which has been extirpated from
most of its historic range. Palis et al. (2006, (p. 5-6) conducted a
study in Florida on a population of the frosted flatwoods salamander
during a drought from 1999-2002. This study found 3 consecutive years
of reproductive failure and a steadily declining adult immigration to
breed at the site as the drought progressed. Taylor et al. (2005, p.
792) noted that wide variation in reproductive success is common among
pond-breeding amphibians that depend on seasonal filling of these
areas, but that adult persistence may buffer against fluctuations in
that success, particularly for species that are long-lived.
Although Palis et al. (2006) suggested that the flatwoods
salamander may only live about 4 years (based on captive animals), we
are currently unsure of the exact life span of wild individuals.
Because of this, it is difficult to predict how long adults could
persist in the landscape without a successful breeding event to
replenish the population. However, Taylor et al. (2005, pp. 792, 796)
constructed a model to look at how many years of reproductive failure
would be required to result in local extinction of pond-breeding
salamanders (with varying life spans) and found that even without total
reproductive failure, populations required moderate to high upland
post-metamorphic survival to persist. In the model, catastrophic
failure created fluctuations in the population, raised the threshold of
survival required to achieve persistence, and imposed the possibility
of extinction even under otherwise favorable environmental conditions.
Reproductive failure for this species was closely tied to hydrologic
conditions; insufficient or short hydroperiod was the primary cause for
complete failure. In addition, early filling of the ponds could also
facilitate the establishment of invertebrate or vertebrate predators
before the salamander eggs hatched (Taylor et al., p. 796). Palis et
al.. (2006, p. 6-7) discussed the necessity of protecting clusters of
flatwoods salamander breeding sites, especially those with different
hydrologic regimes, to guard against population declines at any one
breeding site resulting from stochastic events, such as droughts (Palis
2006, p. 7). Currently, 16 populations of the frosted flatwoods
salamander that occur on public land are supported by multiple breeding
sites.
Habitat fragmentation of the longleaf pine ecosystem resulting from
habitat conversion is primarily a historical threat to the frosted
flatwoods salamander. Large tracts of intact longleaf pine flatwoods
habitat are fragmented by pine plantations, roads, and unsuitable
habitat. Although the threat of ongoing habitat fragmentation has
slowed, the effect of past habitat loss is that many frosted flatwoods
salamander populations are widely separated from each other by
unsuitable habitat. This has been verified through recent reviews of
aerial photography and site visits to localities of historical and
current records for the species. Studies have shown that the loss of
fragmented populations is common, and recolonization is critical for
their regional survival (Fahrig and Merriam 1994, pp. 50-56; Burkey
1995, pp. 527-540). Amphibian populations may be unable to recolonize
areas after local extirpations due to their physiological constraints,
relatively low mobility, and
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site fidelity (Blaustein et al. 1994, pp. 60, 67-68). In the case of
the frosted flatwoods salamander, 38 percent of populations have only
one breeding pond. If the habitat at that site is destroyed,
recolonization would be impossible (see further discussion of
metapopulation dynamics under Factor E).
Roads have contributed to habitat fragmentation by isolating blocks
of remaining contiguous habitat. Roads disrupt migration routes and
dispersal of individuals to and from breeding sites. Road construction
can result in destruction of breeding ponds, as described above. In
addition, vehicles may also cause the death of frosted flatwoods
salamanders when they are attempting to cross roads (Means 1996, p. 2).
Highway construction and associated development resulted in the
destruction of a historic frosted flatwoods salamander breeding pond in
Chatham County, Georgia (Seyle 1994, pp. 3-4).
Off-road vehicle (ORV) use within frosted flatwoods salamander
breeding ponds and their margins severely degrades the wetland habitat.
In the Southeast, ORV use impacts habitat used by frosted flatwoods
salamanders, has the potential to cause direct mortality of individual
salamanders, and is a threat on both public and private land. On public
lands, areas may be designated as off-limits to ORV use (U.S. Forest
Service 2007, p. 19), but these restrictions are difficult to enforce.
Even a single afternoon of individuals riding their ORVs in a pond can
completely destroy the integrity of breeding sites by damaging or
killing the herbaceous vegetation and rutting the substrate (Ripley and
Printiss 2005, pp. 11-12). There is also the potential for direct
injury or mortality of salamanders by ORVs at breeding sites (Ripley
and Printiss 2005, p. 12).
In summary, the loss of habitat was a significant historical threat
to the frosted flatwoods salamander. This range-wide loss of both
upland and wetland habitat occurred primarily due to conversion of
flatwoods sites to agriculture, residential development, and
intensively managed pine plantations. This historic loss of habitat is
presently compounded by current environmental conditions (drought),
proposed projects on private land that do not require U.S. Army Corps
of Engineers (Corps) Corps permits, under the Clean Water Act (33
U.S.C. 1251 et seq.), and the nature of pond-breeding salamanders to
undergo periodic reproductive failure. We consider this threat to be
primarily a past and future threat of moderate magnitude because most
of the remaining occupied habitat of this species occurs on public
lands that are managed to support the native longleaf pine ecosystem.
However, 12 percent of frosted flatwoods salamander populations are on
private land where habitat continues to be degraded by fire suppression
and incompatible management. If the remaining frosted flatwoods
salamander habitat on public land continues to be protected from fire
suppression and other incompatible forest management practices, road
construction, and additional habitat fragmentation, the threat of
habitat loss is expected to be limited. Localized threats on private
lands would include loss or alteration of habitat from agriculture,
residential development, road construction, incompatible forest
management, ORVs, fire suppression, and ditching or draining wetland
breeding sites. As a result, we have determined that the present or
threatened destruction, modification, or curtailment of frosted
flatwoods salamander habitat and range represents a moderate but
significant threat to the species.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Overutilization does not appear to be a threat to the frosted
flatwoods salamander at this time. There is no evidence of a past or
current problem with collection of this species. Consequently, we have
determined that overutilization for commercial, recreational,
scientific, or educational purposes is not a threat to the frosted
flatwoods salamander at this time.
C. Disease or Predation
Although disease has not been specifically documented in the
frosted flatwoods salamander thus far, disease outbreaks with mass
mortality in other species of salamanders indicate that disease may be
a threat for this species as well (Daszak et al.1999, p. 736). ``Red-
leg'' disease (Aeromonas hydrophila), a pathogen bacterium, caused
mortality of mole salamanders (A. talpoideum) at the breeding pond of
the closely related reticulated flatwoods salamander in Miller County,
Georgia (Maerz 2006), and reticulated flatwoods salamanders have not
been observed at this site since the disease was reported. Whiles et
al. (2004, p. 211) found a parasitic nematode (Hedruris siredonis,
family Hedruridae) in larvae of the frosted flatwoods salamander from
South Carolina and Florida. This parasite has been found in other
ambystomatids and can cause individuals to become undersized and thin,
thus reducing their fitness (Whiles et al. 2004, p. 212). The
infestations were not considered heavy and were probably not having a
negative impact on the larvae studied; however, environmental
degradation may change the dynamics between salamander populations and
normally innocuous parasites (Whiles et al. 2004, p. 212). Ranaviruses
in the family Iridoviridae and chytrid fungus may be other potential
threats, although the susceptibility of the frosted flatwoods
salamander to these diseases is unknown. Ranaviruses have been
responsible for die-offs of tiger salamanders throughout western North
America and spotted salamanders (A. maculatum) in Maine (Daszak et al.
1999, p. 736). Chytrid fungus has been discovered and associated with
mass mortality in tiger salamanders in southern Arizona and California,
and the Santa Cruz long-toed salamander (A. macrodactylum croceum)
(Vredenburg and Summers 2001, p. 151; Davidson et al. 2003, p. 601;
Padgett-Flohr and Longcore 2005, p. 50). Chytrid has been found at Fort
Stewart Military Installation in Georgia, a locality where the frosted
flatwoods salamander occurs (Mitchell 2002, p. 191-202). This disease
has negatively impacted populations of other ambystomatid salamanders
(A. macrodactylum croceum) (Vredenburg and Summers 2001; Davidson et
al. 2003; Padgett-Flohr and Longcore 2005), and it is likely to
negatively impact frosted flatwoods salamander populations as well.
This discussion of disease in other species of closely related
salamanders indicates the potential existence of similar threats to
frosted flatwoods salamander populations.
Exposure to increased predation by fish is a threat to the frosted
flatwoods salamander when isolated, seasonally ponded wetland breeding
sites are changed to or connected to more permanent wetlands inhabited
by fish species not typically found in temporary ponds. Studies of
other ambystomatid species have demonstrated a decline in larval
survival in the presence of predatory fish (Semlitsch 1987, p. 481).
Ponds may be modified specifically to serve as fish ponds or sites may
be altered because of drainage ditches, firebreaks, or vehicle tracks
that can all provide avenues for fish to enter the wetlands.
Red imported fire ants (Solenopsis invicta) are potential predators
of flatwoods salamanders, especially in disturbed areas. They have been
seen in areas disturbed by the installation of drift fences at known
frosted flatwoods salamander breeding sites (Palis 2008).
[[Page 54130]]
Mortality of amphibians trapped at drift fences has occurred when fire
ants were present and traps were not monitored with sufficient
frequency (NCASI 2002, p. 6). The severity and magnitude of effects, as
well as the long-term effect, of fire ants on frosted flatwoods
salamander populations are currently unknown.
In summary, diseases of amphibians in the southeastern United
States remain largely unstudied. However, given the incidence of
disease in species that could be considered surrogates for the frosted
flatwoods salamander, the probability exists for similar infections to
occur in frosted flatwoods salamander populations. We consider this to
be a potential threat of low magnitude. Predation by fish is a historic
threat that continues to be a localized problem when ditches,
firebreaks, or vehicle ruts provide connections allowing the movement
of fish from permanent water bodies into frosted flatwoods salamander
breeding sites. Fire ants also have the potential of being a localized
threat, particularly in disturbed areas. We consider these threats to
be potential threats of low magnitude because 88 percent of frosted
flatwoods salamander populations occur primarily on public lands where
they are relatively protected.
D. The Inadequacy of Existing Regulatory Mechanisms
There are no existing regulatory mechanisms for the protection of
the upland habitats where frosted flatwoods salamanders spend most of
their lives. Section 404 of the Clean Water Act is the primary Federal
law that has the potential to provide some protection for the wetland
breeding sites of the frosted flatwoods salamander. However, due to
recent case law (Solid Waste Agency of Northern Cook County (SWANCC) v.
U.S. Army Corps of Engineers 531 U.S. 159 (2001); Rapanos v. U.S. 547
U.S. 715 (2006)), isolated wetlands are no longer considered to be
under Federal jurisdiction (not regulatory wetlands). Wetlands are only
considered to be under the jurisdiction of the Corps if a ``significant
nexus'' exists to a navigable waterway or its tributaries. Currently,
some Corps Districts do not coordinate with us on flatwoods salamanders
and, since isolated wetlands are not considered under their
jurisdiction, they are often not included on maps in permit
applications (Brooks 2008). However, since most remaining frosted
flatwoods salamander populations are on public land, which is unlikely
to be developed, we do not consider this to be a significant threat.
Longleaf pine habitat management plans have been written for public
lands occupied by the frosted flatwoods salamander. They include
management plans for State-owned lands and integrated natural resource
management plans (INRMPs) for Department of Defense lands. Most of the
plans contain specific goals and objectives regarding habitat
management, including prescribed burning, that would benefit frosted
flatwoods salamanders. Multiple-use is the guiding principle on most of
these public lands, however, and protection of the frosted flatwoods
salamander may be just one of many management goals including timber
production and military and recreational use.
At the State and local levels, regulatory mechanisms are limited.
The flatwoods salamander is listed as a threatened species in the State
of Georgia (Jensen 1999, pp. 92-93). This designation protects the
species by preventing its sale, purchase, or possession in Georgia and
by prohibiting actions that cause direct mortality of the species or
the destruction of its habitat on lands owned by the State of Georgia
(Ozier 2008). However, there are no known frosted flatwoods salamander
populations on lands owned by the State of Georgia. In 2001, the
Florida Fish and Wildlife Conservation Commission (FFWCC) listed the
flatwoods salamander (which includes the frosted flatwoods salamander)
as a species of special concern (FFWCC 2007, p. 2) and prohibited
direct take except through permit. As part of the listing process, a
Statewide management plan was developed for the salamander in Florida
(FFWCC 2001, p. 1-60). This plan sets an ambitious conservation goal of
maintaining at least 129 self-sustaining populations of flatwoods
salamanders (which includes both frosted and reticulated flatwoods
salamander species) in Florida. The plan also outlines a monitoring
plan for population status assessment, an implementation strategy for
the management of populations, and areas for future research. However,
Florida regulations offer no protection against the most significant
threat to the frosted flatwoods salamander--loss of habitat.
In summary, although existing regulatory mechanisms provide little
direct protection of frosted flatwoods salamanders (beyond the
protections afforded by the Act), they do provide a degree of
protection for the remaining occupied habitat, primarily on public
lands. The record of management on public lands since the original
listing of the flatwoods salamander in 1999 indicates that public
agencies are actively pursuing longleaf pine ecosystem management
programs that benefit the frosted flatwoods salamander. Frosted
flatwoods salamander breeding sites on the three private land sites
may, in some cases, come under the jurisdiction of the Corps, but most
likely they are provided little regulatory protection. We have
determined that the threat of inadequate existing regulatory mechanisms
is primarily an ongoing threat of moderate magnitude.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Metapopulations, which are neighboring local populations close
enough to one another that dispersing individuals could be exchanged
(gene flow) at least once per generation, are important to the long-
term survival of temporary pond breeding amphibians. In these species,
such as the frosted flatwoods salamander, breeding ponds may differ in
the frequency of their ability to support amphibian reproduction. As a
result, extirpation and colonization rates can be a function of pond
spatial arrangement as well as local habitat quality (Marsh and Trenham
2001, p. 41). Of the 26 known frosted flatwoods salamanders
populations, 16 (62 percent) are supported by more than one breeding
pond and may be considered metapopulations. However, for 12 percent (3
out of 26) of the known frosted flatwoods salamander populations, any
one of the many threats that may render a breeding pond unsuitable
could cause the extirpation of the affected population.
Invasive plant species, such as cogongrass (Imperata cylindrica),
threaten to further degrade existing flatwoods habitat. Cogongrass, a
perennial grass native to Southeast Asia, is one of the leading threats
to the ecological integrity of native herbaceous flora, including that
in the longleaf pine ecosystem (Jose et al. 2002, p. 43). Cogongrass
can displace most of the existing vegetation except large trees.
Especially threatening to the frosted flatwoods salamander is the
ability of cogongrass to outcompete wiregrass, a key vegetative
component of flatwoods salamander habitat. Changing the species
composition in this way can alter the soil chemistry, nutrient cycling,
and hydrology of an infested site (Jose et al. 2002, p. 43). Frosted
flatwoods salamander habitat management plans will need to address
threats posed by cogongrass and other invasive plant species and
include strategies to control them. An integrated
[[Page 54131]]
management approach to controlling cogongrass is outlined in Jose et
al. (2002, p. 42).
Pesticides (including herbicides) may pose a threat to amphibians,
such as the frosted flatwoods salamander, whose permeable eggs and skin
readily absorb substances from the surrounding aquatic or terrestrial
environment (Duellman and Trueb 1986, pp. 199-200). Negative effects
that commonly used pesticides and herbicides may have on amphibians
include delayed metamorphosis, paralysis, reduced growth rate, and
mortality (Bishop 1992, pp. 67-69). Herbicides used near frosted
flatwoods salamander breeding ponds may alter the density and species
composition of vegetation surrounding a breeding site and reduce the
number of potential sites for egg deposition, larval development, or
shelter for migrating salamanders. Aerial spraying of herbicides over
outdoor pond mesocosms (semi-field approximations of ponds) has been
shown to reduce zooplankton diversity, a food source for larval frosted
flatwoods salamanders, and cause very high (68 to 100 percent)
mortality in tadpoles and juvenile frogs (Relyea 2005, pp. 618-626).
The potential for negative effects from pesticide and herbicide use in
areas adjacent to breeding ponds would be reduced by avoiding aerial
spraying (Tatum 2004, p. 1047).
Studies of other ambystomatid species have demonstrated a decline
in larval survival in the presence of predatory fish, as mentioned
above under Factor C. One of the potential reasons for this decline may
be the negative effect that these fish have on the invertebrate prey of
salamander larvae. The invertebrates found by Whiles et al. (2004, p.
212) in a study of larval frosted and reticulated flatwoods salamander
gut contents are typical of freshwater habitats in the Southeast that
do not contain predatory fish on a regular basis. The presence of
predatory fish has a marked effect on invertebrate communities and
alters prey availability for larval salamanders with the potential for
negative effects on larval fitness and survival (Semlitsch 1987, p.
481). Wherever connections have been created between permanent water
and frosted flatwoods salamander ponds, through installation of
firebreaks, ditches, and so on, this threat from predatory fish exists.
Studies of frosted flatwoods salamander populations since the
original species classification of flatwoods salamander was listed (64
FR 15691; April 1, 1999) have been limited due to drought. Data on the
numbers of adults within existing populations does not exist. However,
given the low number of individuals encountered even when breeding is
verified, populations are likely to be very small at any given breeding
site. Small populations are at increased threat of extirpation from
natural processes (genetic isolation, inbreeding depression, and
drought), as well as the manmade threats described above.
In summary, a variety of natural or manmade factors historically or
currently threaten, or have the potential to threaten, the frosted
flatwoods salamander. The loss of metapopulation structure in the
distribution of frosted flatwoods salamander populations was a range-
wide threat that caused historic losses of this species. It continues
to be a current threat for 38 percent of the remaining frosted
flatwoods salamander populations. Fire suppression and inadequate
habitat management continue to cause the degradation of occupied sites,
primarily on private land. Invasive plant species probably did not have
much of a historic impact on salamander populations, but they are a
range-wide potential threat, especially as they become more widespread
and difficult to control. Rangewide, low population densities have been
a historic threat and continue to be a threat for most frosted
flatwoods salamander populations, particularly due to past and current
drought conditions, habitat loss, population fragmentation, and
periodic reproductive failures that occur naturally in pond-breeding
amphibians. The impact that competing predators may have on the
salamanders' prey base, and the threat of pesticide and herbicide use,
are less clear as historic threats but remain potential localized
threats for the species. Therefore, while we have determined that other
natural and manmade factors, such as invasive species, pesticides, and
competition for the species' prey base, may threaten the frosted
flatwoods salamander, the severity and magnitude of these threats are
not currently known. Acting in combination with threats listed above
under Factors A through D, the threats under Factor E could increase
the severity of the other threats.
Determination
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the frosted flatwoods salamander. In summary, the most significant
historical threat to the frosted flatwoods salamander, as listed in
Factor A (above), is loss of the majority of its habitat. A variety of
localized threats (described under Factors A, C, D, and E) have the
potential to impact the remaining frosted flatwoods salamander habitat.
These include alterations in the hydrology of existing wetland breeding
sites, incompatible forest management, ORV use, fire suppression,
drought, and disease, but the severity and magnitude of these threats
are not currently known. As described in Factor E above, small
populations are at increased threat of extirpation from natural
processes (genetic isolation, inbreeding depression, and drought), as
well as the manmade threats listed above. Finally, there are potential
localized threats from fire ants, pesticides, and invasive plants for
which the extent of impact is yet undeterminable, but that we believe
are legitimate threats due to both their impact on surrogate species
and their prevalence in the types of habitats used by this species.
Only 26 frosted flatwoods salamander populations are known. Ten (38
percent) of these populations are supported by only one breeding site.
A population with only one breeding site has a tenuous future just
given randomly varying environmental factors without considering the
additional threats of habitat destruction and degradation that further
threaten these populations.
As noted previously, we are currently experiencing drought
conditions. Palis et al. (2006, pp. 5-6) studied a frosted flatwoods
population in Florida during a drought from 1999-2002. This study
documented 3 consecutive years of reproductive failure and a steady
declining adult immigration to the site for breeding as the drought
progressed.
Catastrophic reproductive failure occurs even in healthy
populations of pond-breeding amphibians. When it does occur, the
modeling efforts of Taylor et al. (2005, p. 796) showed that each year
of reproductive failure raises the threshold of survival required to
achieve persistence and imposes the possibility of extirpation even
under otherwise favorable environmental conditions. Taylor et al.
(2005, p. 799) reminds us that particularly with small populations or
low population growth rates (as exists with the frosted flatwoods
salamander) effects of reproductive failure are made worse by
demographic stochasticity. Even in populations with multiple breeding
ponds, amphibian populations may be unable to recolonize areas after
local extirpations due to their physiological constraints, relatively
low mobility, and site fidelity (Blaustein et al. 1994, pp. 60, 67-68).
For frosted flatwoods salamander, 38 percent of populations have
only one breeding pond. If the habitat at that site
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is destroyed, recolonization would be impossible and the population
supported by that breeding pond would be extirpated.
Habitat loss on private lands is an imminent threat that is
compounded by a variety of other factors. Fire suppression on private
lands occupied by the frosted flatwoods salamander represents one of
the biggest threats to the species' habitat and the continued existence
of the species on these sites. However, 62 percent of frosted flatwoods
salamander populations have an improved chance of surviving demographic
and environmental stochasticity given that the distribution of breeding
sites occurs within an adult salamander's dispersal distance.
We believe that, when combining the effects of historical, current,
and projected habitat loss and degradation, historical and ongoing
drought, and the exacerbating effects of disease, predation, small
population size, and isolation, the frosted flatwoods salamander
continues to be likely to become an endangered species throughout all
of its range within the foreseeable future. We believe these threats,
particularly the threats to populations resulting from habitat
degradation and fragmentation, small population size, and drought, are
current and are projected to continue into the future. We have
determined that these threats are operating on the species and its
habitat with a moderate degree of magnitude throughout most of its
range and with a moderate degree of severity, as discussed above.
Based on the best available scientific and commercial information,
we have determined that the preferred action is for the frosted
flatwoods salamander to retain its status as a threatened species under
the Act. Without the protection of the Act, significant management of
threats would likely occur on public lands; however, there is still
substantial risk of loss of ponds to drought and disease and, on
private lands, a variety of potential threats (for example,
introduction of fish, predation, pesticides), and development. As
discussed previously, declines resulting from drought can occur within
only a few years. In the case of the frosted flatwoods salamander, 38
percent of populations have only one breeding pond. If the habitat at
that site is destroyed, recolonization would be impossible and the
population supported by that breeding pond would be extirpated. This
could occur within a few years given recurring drought conditions and
existing threats. While not in immediate danger of extinction, the
frosted flatwoods salamander is likely to become an endangered species
in the foreseeable future throughout all or a significant portion of
its range if the present trends that negatively affect the species, and
its limited and restricted habitat, continue. Furthermore, because
these threats to the species are of comparable magnitude and severity
across all of the species' range, we have determined that an analysis
of whether a specific portion of the range might require a different
listing status is not warranted at this time.
Available Conservation Measures
For additional information on available conservation measures,
please refer to the proposed rule published in the Federal Register on
August 13, 2008 (73 FR 47258).
References Cited
A complete list of all references cited in this document is
available upon request from the Field Supervisor Ray Aycock,
Mississippi Field Office (see FOR FURTHER INFORMATION CONTACT).
Author(s)
The primary authors of this package are the staff of the
Mississippi 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: September 5, 2008.
Lyle Laverty,
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. E8-21878 Filed 9-17-08; 8:45 am]
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