[Federal Register: March 19, 2003 (Volume 68, Number 53)]
[Rules and Regulations]
[Page 13497-13520]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19mr03-18]
[[Page 13497]]
-----------------------------------------------------------------------
Part III
Department of the Interior
-----------------------------------------------------------------------
Fish and Wildlife Service
-----------------------------------------------------------------------
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Determination of
Endangered Status for the Sonoma County Distinct Population Segment of
the California Tiger Salamander; Final Rule
[[Page 13498]]
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018-AI61
Endangered and Threatened Wildlife and Plants; Determination of
Endangered Status for the Sonoma County Distinct Population Segment of
the California Tiger Salamander
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: We, the Fish and Wildlife Service (Service), determine
endangered status for the Sonoma County distinct population segment
(DPS) of the California tiger salamander (Ambystoma californiense),
under the Endangered Species Act of 1973, as amended (Act). In Sonoma
County, the California tiger salamander is imperiled by a variety of
factors including habitat destruction, degradation, and fragmentation
due to urban development, hybridization with non-native salamanders,
inadequate regulatory mechanisms, disease, and pesticide drift. We
listed this DPS on an emergency basis on July 22, 2002. The emergency
designation expires on March 19, 2003. This rule is effective upon
publication in the Federal Register, and implements the Federal
protection and recovery provisions afforded by the Act for the Sonoma
County DPS of the California tiger salamander. This final rule is being
issued as a result of a settlement agreement and consent decree.
DATES: This rule is effective on March 19, 2003.
ADDRESSES: The complete file for this final rule is available for
inspection, by appointment, during normal business hours at the
Sacramento Fish and Wildlife Office, U.S. Fish and Wildlife Service,
2800 Cottage Way, Suite W-2605, Sacramento, CA 95825.
FOR FURTHER INFORMATION CONTACT: David E. Wooten, Susan Moore, or Chris
Nagano, Sacramento Fish and Wildlife Office, at the address listed
above (telephone 916/414-6600; facsimile 916/414-6713).
SUPPLEMENTARY INFORMATION:
Background
The California tiger salamander was first described as Ambystoma
californiense by Gray in 1853, based on specimens that had been
collected in Monterey, California (Grinnell and Camp 1917). Storer
(1925) and Bishop (1943) also considered the California tiger
salamander to be a distinct species. Dunn (1940), Gehlbach (1967), and
Frost (1985) stated that the California tiger salamander was a
subspecies of the more widespread tiger salamander (Ambystoma
tigrinum). However, based on recent studies of the genetics, geographic
distribution, and ecological differences among the members of the A.
tigrinum complex, the California tiger salamander is now considered to
be a distinct species (Shaffer and Stanley 1991; Shaffer et al. 1993;
Jones 1993; Shaffer and McKnight 1996; Irschick and Shaffer 1997;
Petranka 1998). The range of this animal does not naturally overlap
with any other species of tiger salamander (Stebbins 1985; Petranka
1998).
The California tiger salamander is a large, stocky, terrestrial
salamander with small eyes and a broad, rounded snout. Adults may reach
a total length of 208 millimeters (mm) (8.2 inches (in)), with males
generally averaging about 203 mm (8 in) in total length and females
averaging about 173 mm (6.8 in) in total length. For both sexes, the
average snout-vent length is approximately 91 mm (3.6 in). The small
eyes have black irises and protrude from the head. Coloration consists
of white or pale yellow spots or bars on a black background on the back
and sides. The belly varies from almost uniform white or pale yellow to
a variegated pattern of white or pale yellow and black. Males can be
distinguished from females, especially during the breeding season, by
their swollen cloacae (a common chamber into which the intestinal,
urinary, and reproductive canals discharge), more developed tail fins,
and larger overall size (Stebbins 1962; Loredo and Van Vuren 1996).
California tiger salamanders are restricted to vernal pools and
seasonal ponds in grassland and oak savannah plant communities from sea
level to about 460 meters (m) (1,500 feet (ft)) (Stebbins 1989; Shaffer
et al. 1993; Jennings and Hayes 1994; Petranka 1998; California Natural
Diversity Data Base (CNDDB) 2002). Genetic studies of the California
tiger salamander suggest that levels of interchange among populations
are very low, and that populations or groups of subpopulations
(metapopulations) are genetically isolated from one another (Shaffer et
al. 1993; Shaffer and Trenham 2002). Studies of mitochondrial DNA and
allozymes (proteins) indicate that there are six populations of
Ambystoma californiense, which are found in: (1) The Santa Rosa area of
Sonoma County; (2) the Bay Area (central and southern Alameda, Santa
Clara, western Stanislaus, western Merced, and the majority of San
Benito counties); (3) the Central Valley (Yolo, Sacramento, Solano,
eastern Contra Costa, northeast Alameda, San Joaquin, Stanislaus,
Merced, and northwestern Madera counties); (4) southern San Joaquin
Valley (portions of Madera, central Fresno, and northern Tulare and
Kings counties); (5) the Central Coast Range (southern Santa Cruz,
Monterey, northern San Luis Obispo, and portions of western San Benito,
Fresno, and Kern counties); and (6) Santa Barbara County (Shaffer and
Trenham 2002).
The California tiger salamander in Sonoma County inhabits low-
elevation (below 60 m (200 ft)) vernal pools and seasonal ponds,
associated grassland, and oak savannah plant communities. The historic
range of the species also may have included the Petaluma River
watershed, as there is one historic record of a specimen from the
vicinity of Petaluma from the mid-1800s (Borland 1856, as cited in
Storer 1925).
California tiger salamanders found in the Santa Rosa Plain in
Sonoma County are geographically separated from other California tiger
salamander populations. The closest California tiger salamander
populations to Sonoma County are located in Contra Costa, Yolo, and
Solano counties, which are separated from the Sonoma County population
by the Coast Range, Napa River, and the Carquinez Straits, a distance
of about 72 kilometers (km) (45 miles (mi)).
Subadult and adult California tiger salamanders spend the dry
summer and fall months of the year estivating (a state of dormancy or
inactivity in response to hot, dry weather) in the burrows of small
mammals, such as California ground squirrels (Spermophilus beecheyi)
and Botta's pocket gopher (Thomomys bottae) (Storer 1925; Loredo and
Van Vuren 1996; Petranka 1998; Trenham 1998a). During estivation,
California tiger salamanders eat very little (Shaffer et al. 1993).
Once fall or winter rains begin, they emerge from these retreats on
rainy nights to feed and to migrate to the breeding ponds (Stebbins
1985, 1989; Shaffer, et al. 1993). The salamanders breeding in, and
living around, a seasonal pool or pools, and associated uplands where
estivation can occur are said to occupy a breeding site. A breeding
site is defined as a location where the animals are able to
successfully breed in years of ``normal'' rainfall and complete their
estivation (derived from Trenham 1998b and 2001). Normal rainfall in
Santa Rosa is 76 centimeters (cm) (30 in) per year (National Weather
Service 2002).
Occurrence of California tiger salamanders in Sonoma County is
significantly associated with occurrence
[[Page 13499]]
of gophers (D. Cook, The Wildlife Society, pers. comm., 2002). Active
gopher burrows probably are needed to sustain California tiger
salamanders because inactive burrow systems become progressively
unsuitable over time. California tiger salamanders cannot persist
without estivation habitat.
Adult California tiger salamanders may migrate up to 2 km (1 mi)
from their estivation sites to the breeding ponds (S. Sweet, University
of California, Santa Barbara, in litt., 1998), which may be vernal
pools, stockponds, or other seasonal water bodies. The distance between
the estivation sites and breeding pools depends on local topography and
vegetation, and the distribution of ground squirrel or other rodent
burrows (Stebbins 1989; Lawrence Hunt, consultant, in litt., 1998).
Males migrate before females (Twitty 1941; Shaffer et al. 1993; Loredo
and Van Vuren 1996; Trenham 1998b). Males usually remain in the ponds
for an average of about 6 to 8 weeks, while females stay for
approximately 1 to 2 weeks. In dry years, both sexes may stay for
shorter periods (Loredo and Van Vuren 1996; Trenham 1998b). Most marked
salamanders have been recaptured at the pond where they were initially
captured; in one study approximately 80 percent were recaptured at the
same pond (Trenham 1998b). The rate of natural movement of salamanders
among breeding sites depends on the distance between the ponds or
complexes of ponds and on the intervening habitat (e.g., salamanders
may move more quickly through sparsely covered and more open grassland
than densely vegetated lands) (Trenham 1998a). As with migration
distances, the number of ponds used by an individual over its lifetime
will be dependent on landscape features and environmental factors.
The adults mate in the ponds and the females lay their eggs in the
water (Twitty 1941; Shaffer et al. 1993; Petranka 1998). Females attach
their eggs singly, or in rare circumstances, in groups of two to four,
to twigs, grass stems, vegetation, or debris (Storer 1925; Twitty
1941). In ponds with no or limited vegetation, they may be attached to
objects, such as rocks and boards on the bottom (Jennings and Hayes
1994). After breeding, adults leave the pool and return to the small
mammal burrows (Loredo et al. 1996; Trenham 1998a), although they may
continue to come out nightly for approximately the next 2 weeks to feed
(Shaffer et al. 1993). In drought years, the seasonal pools may not
form and the adults can not breed (Barry and Shaffer 1994).
Salamander eggs hatch in 10 to 14 days with newly hatched
salamanders (larvae) ranging from 11.5 to 14.2 mm (0.45 to 0.55 in) in
total length (Petranka 1998). The larvae are aquatic. They are
yellowish gray in color and have broad fat heads, possess large,
feathery external gills, and broad dorsal fins that extend well onto
their back. The larvae feed on zooplankton, small crustaceans, and
aquatic insects for about 6 weeks after hatching, after which they
switch to larger prey (J. Anderson 1968). Larger larvae have been known
to consume smaller tadpoles of Pacific treefrogs (Pseudacris regilla)
and California red-legged frogs (Rana aurora) (J. Anderson 1968; P.
Anderson 1968). The larvae are among the top aquatic predators in the
seasonal pool ecosystems. They often rest on the bottom in shallow
water, but also may be found at different layers in the water column in
deeper water. The young salamanders are wary and when approached by
potential predators will dart into vegetation on the bottom of the pool
(Storer 1925).
The larval stage of the California tiger salamander usually lasts 3
to 6 months, as most seasonal ponds and pools dry up during the summer
(Petranka 1998). Amphibian larvae must grow to a critical minimum body
size before they can metamorphose (change into a different physical
form) to the terrestrial stage (Wilbur and Collins 1973). Individuals
collected near Stockton in the Central Valley during April varied from
47 to 58 mm (1.85 to 2.3 in) in length (Storer 1925). Feaver (1971)
found that larvae metamorphosed and left the breeding pools 60 to 94
days after the eggs had been laid, with larvae developing faster in
smaller, more rapidly drying pools. The longer the ponding duration,
the larger the larvae and metamorphosed juveniles are able to grow, and
the more likely they are to survive and reproduce (Pechmann et al.
1989; Semlitsch et al. 1988; Morey 1998; Trenham 1998b). The larvae
will perish if a site dries before they complete metamorphosis (P.
Anderson 1968; Feaver 1971). Pechmann et al. (1989) found a strong
positive correlation between ponding duration and total number of
metamorphosing juveniles in five salamander species. In Madera County,
Feaver (1971) found that only 11 of 30 pools sampled supported larval
California tiger salamanders, and five of these dried before
metamorphosis could occur. Therefore, out of the original 30 pools,
only six (20 percent) provided suitable conditions for successful
reproduction that year. Size at metamorphosis is positively correlated
with stored body fat and survival of juvenile amphibians, and
negatively correlated with age at first reproduction (Semlitsch et al.
1988; Scott 1994; Morey 1998).
When the metamorphosed juveniles leave their ponds in the late
spring or early summer, before the ponds dry completely, they settle in
small mammal burrows at the end of their nightly movements (Zeiner et
al. 1988; Shaffer et al. 1993; Loredo et al. 1996). Like the adults,
juveniles may emerge from these retreats to feed during nights of high
relative humidity (Storer 1925; Shaffer et al. 1993) before settling in
their selected estivation sites for the dry, hot summer months.
Juveniles have been observed to migrate up to 1.6 km (1 mi) from
breeding ponds to estivation areas (Austin and Shaffer 1992).
An estimated 83 percent of the salamanders rely on rodent burrows
for shelter (Petranka 1998). Mortality of juveniles during their first
summer exceeds 50 percent (Trenham 1998b). Emergence from estivation in
hot dry weather occasionally results in mass mortality of juveniles
(Holland et al. 1990). Juveniles do not typically return to the
breeding pools until they reach sexual maturity at several years of age
(Trenham 1998b; L. Hunt, in litt., 1998). Trenham (1998b) estimated
survival from metamorphosis to maturity at his study site at less than
5 percent, well below the estimated replacement level of 18 percent
that would maintain the population. Adult survivorship varies greatly
between years, but is a crucial determinant of whether a population is
a source or sink (i.e., whether net productivity exceeds the level
necessary to maintain the population).
Lifetime reproductive success for California and other tiger
salamanders is low. Trenham et al. (2000) found the average female bred
1.4 times and produced 8.5 young that survived to metamorphosis per
reproductive effort. This resulted in roughly 11 metamorphic offspring
over the lifetime of a female. Preliminary data suggest that most
individuals of the California tiger salamanders require 2 years to
become sexually mature, but some individuals may be slower to mature
(Shaffer et al. 1993). Some animals do not breed until they are 4 to 6
years old. While individuals may survive for more than 10 years, many
breed only once, and in some populations, less than 5 percent of marked
juveniles survive to become breeding adults (Trenham 1998b). With such
low recruitment, isolated populations can decline greatly from unusual,
randomly occurring natural events as well as from human caused factors
that reduce breeding success and individual survival. Factors
[[Page 13500]]
that repeatedly lower breeding success in isolated ponds that are too
far from other ponds for migrating individuals to replenish the
population can quickly extirpate a population.
The total number of individual California tiger salamanders in
Sonoma County is not known. The difficulty of estimating total
California tiger salamander population size has been discussed by a
number of biologists (Shaffer et al. 1993; Jennings and Hayes 1994).
However, estimates have been made for a few populations in Monterey
(Barry and Shaffer 1994; Trenham et al. 1998b). Because data on numbers
of individual California tiger salamanders are lacking since these
amphibians spend much of their lives underground, and because only a
portion of the total number of animals migrate to pools to breed each
year, the availability of suitable habitat and documentation of its
loss is thus an appropriate method for assessing the status of the
species.
The life history and ecology of the California tiger salamander on
the Santa Rosa Plain in Sonoma County make it likely that this
population has a metapopulation structure (Hanski and Gilpin 1991). A
metapopulation is a set of local populations or breeding sites within
an area, where typically migration from one local population or
breeding site to other areas containing suitable habitat is possible,
but not routine. Movement between areas containing suitable habitat
(i.e., dispersal) is restricted due to inhospitable conditions around
and between areas of suitable habitat. Because many of the areas of
suitable habitat may be small, and support small numbers of
salamanders, local extinction of these small units may be common. A
metapopulation's persistence depends on the combined dynamics of these
local extinctions and the subsequent recolonization of these areas by
dispersal (Hanski and Gilpin 1991, 1997; McCullough 1996; Hanski 1999).
We believe habitat loss has reduced the sizes and connectivity
between patches of suitable and occupied salamander habitat on the
Santa Rosa Plain. The reduction in the extent and amount of suitable
water bodies, grasslands, and other suitable upland habitats likely has
eliminated connectivity among most of the known breeding sites, making
recolonization of some sites more difficult following local extinction.
In addition, the reduction of habitat below a certain size threshold
has the effect of reducing the quality of the remaining habitat by
reducing the size of habitat boundaries, and making effects of other
factors such as amount of food, availability of rodent burrows,
pesticide use, mortality from vehicles, and predators more pronounced
given the smaller area now exposed to such impacts. We do not have
enough data to determine what the size threshold for habitat might be,
whereby any further reduction would lower the quality of the remaining
habitat. The acreage is probably dependent on factors such as the type
of building occurring along habitat boundaries (i.e., residential,
industrial, community park), number of roads bordering the habitat and
the amount of traffic those roads experience, amount of pesticide use
within the breeding pool watershed, or whether domestic animals or
people have access to the site during periods when salamanders are
vulnerable, such as migrating to or from estivation sites. We believe
there is a size threshold for habitat below which the combination of
various impacts will result in the loss of more salamanders than the
Sonoma County California tiger salamander population can produce, and
thus local extinction will occur.
Distinct Vertebrate Population Segment
Under the Act, we must consider for listing any species,
subspecies, or, for vertebrates, a DPS of these taxa, if there is
sufficient information to indicate that such action may be warranted.
To implement the measures prescribed by the Act and its Congressional
guidance, we, along with the National Marine Fisheries Service,
developed policy that addresses the recognition of DPSs for potential
listing actions (61 FR 4722). The policy allows for a more refined
application of the Act that better reflects the biological needs of the
taxon being considered, and avoids the inclusion of entities that do
not require its protective measures. Under our DPS policy, we use two
elements to assess whether a population segment under consideration for
listing may be recognized as a DPS. The elements are: (1) The
population segment's discreteness from the remainder of the species to
which it belongs; and (2) the significance of the population segment to
the species to which it belongs. If we determine that a population
segment being considered for listing represents a DPS, then the level
of threat to that population segment is evaluated based on the five
listing factors established by the Act to determine if listing it as
either threatened or endangered is warranted.
Discreteness
A population segment of a vertebrate species may be considered
discrete if it satisfies either one of the following two conditions:
(1) It is markedly separated from other populations of the same taxon
as a consequence of physical, physiological, ecological, or behavioral
factors (Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation.); or (2) it is
delimited by international governmental boundaries within which
significant differences in control of exploitation, management of
habitat, conservation status, or regulatory mechanisms exist.
The Sonoma County California tiger salamander is discrete in
relation to the remainder of the species. The population is
geographically isolated and separate from other California tiger
salamanders. The Sonoma County population is widely separated
geographically from the closest populations, which are located in
Contra Costa, Yolo, and Solano counties. These populations are
separated from the Sonoma County population by the Coast Range, Napa
River, and the Carquinez Straits, at a minimum distance of about 72 km
(45 mi). There are no known records of the California tiger salamander
in the intervening areas (D. Warenycia, CDFG, pers. comm., 2002). We
have no evidence of natural interchange of individuals between the
Sonoma County population and other California tiger salamander
populations. As detailed below, this finding is supported by an
evaluation of the genetic variability of the species.
Dr. H. Bradley Shaffer has analyzed the population genetics of the
California tiger salamander (Shaffer et al. 1993; Shaffer and Trenham
2002). The most recently available and most comprehensive mitochondrial
DNA (mtDNA) sequence data indicate that there are six populations of
California tiger salamander; these six populations are distinguished
from one another by their mtDNA characteristics (Shaffer and Trenham
2002). Shaffer et al. 1993 reported that the sequence divergence (a
percentage indicating the difference among DNA sequences studied)
between the Sonoma County population was found to diverge on the order
of 2 percent from other populations of this species. This high level of
genetic divergence indicates that there has been little, if any, gene
flow for a significant period of time between the Sonoma County
population and other California tiger salamander populations. These
results are supported by additional sampling and mtDNA work of Shaffer
and Trenham (2002). The ``first, deepest and most significant
phylogenetic split within California tiger salamander samples is
between Sonoma County and all others'' (H.B. Shaffer, University of
[[Page 13501]]
California, Davis, in litt, 2002). This is illustrated by the
phylogenetic tree based on mtDNA in which Sonoma County California
tiger salamander is the first branch after the outgroup (groups known
from independent evidence to have branched off earlier than the groups
under study; Avise 1994, Weir 1996) (Shaffer and Trenham 2002). This
branch is strongly supported statistically (with bootstrap probability
of 100 percent) on a phylogenetic tree constructed by the neighbor
joining method (a method used to construct phylogenetic trees; NJ,
Avise 1994, Weir 1996). Bootstrapping is a method of statistically
testing the significance of particular patterns; it involves resampling
(with replacement) from the existing data sets and then reassessing the
frequency with which particular groups appear in trees generated from
the resampled data (Avise 1994, Weir 1996). For the Sonoma County
California tiger salamander branch a bootstrap probability of 100
percent means that 100 percent of the trees generated from the
resampled data had the same configuration. A bootstrap probability of
seventy percent is the normal criterion for statistical significance in
the systematic literature (Hillis and Bull 1993 as cited in Shaffer and
McKnight 1996). In addition to being strongly supported using the NJ
method, the branch pattern indicating that the Sonoma County population
is distinct is supported by maximum likelihood and parsimony (Shaffer
and Trenham 2002), two other methods of constructing phylogenetic trees
(Avise 1994, Weir 1996). In addition, Shaffer and Trenham (2002) report
preliminary results of analyses of two nuclear genes. These preliminary
results also show that Sonoma County California tiger salamanders are
genetically distinct from other California tiger salamanders. Shaffer
et al. (1993) suggest that the differences are so large that the Sonoma
County population may warrant separate taxonomic recognition (Shaffer
et al. 1993).
In the proposed rule we relied on the 2 percent divergence value as
evidence that the Sonoma County California tiger salamander population
is discrete. At the time, we were using the best available information
(Shaffer et al. 1993). We note that systematists typically identify
species boundaries by using phylogenetic analysis rather than absolute
levels of sequence divergence (Avise 1994, Weir 1996, Hedrick 2000). As
noted above, the phylogenetic tree (which indicates relationships among
populations or groups) constructed from the more comprehensive mtDNA
data of Shaffer and Trenham (2002) indicates that Sonoma County
California tiger salamanders are very distinct relative to other
California tiger salamanders, and separated from them on a branch that
is strongly supported statistically. Therefore, the most comprehensive
available genetic data (Shaffer and Trenham 2002) for California tiger
salamanders strongly indicate that Sonoma County California tiger
salamanders are distinct from other populations of the species.
Significance
Under our DPS policy, once we have determined that a population
segment is discrete, we consider its biological and ecological
significance to the larger taxon to which it belongs. This
consideration may include, but is not limited to, evidence of the
persistence of the discrete population segment in an ecological setting
that is unique for the taxon; evidence that loss of the population
segment would result in a significant gap in the range of the taxon;
evidence that the population segment represents the only surviving
natural occurrence of a taxon that may be more abundant elsewhere as an
introduced population outside its historic range; and evidence that the
discrete population segment differs markedly from other populations of
the species in its genetic characteristics. We have found substantial
evidence that two of these significance factors are met by the
population of the California tiger salamander that occurs on the Santa
Rosa Plain in Sonoma County.
The extinction of the Sonoma County population would result in the
loss of a significant genetic entity and the curtailment of the range
of the species. As discussed above, the Sonoma County population is
genetically distinct from other populations of California tiger
salamanders. Loss of the Sonoma County population would also eliminate
the most northern coastal extent of the range of the species. The
Sonoma County population is geographically isolated. Genetic analysis
of the species supports the hypothesis that no natural interchange of
the Sonoma County population occurs with other California tiger
salamander populations.
Conclusion
We evaluated the Sonoma County population, addressing the two
elements which our policy requires us to consider in deciding whether a
vertebrate population may be recognized as a DPS and considered for
listing under the Act. We conclude that the Sonoma County population is
discrete, as per our policy, based on its geographic separation and
genetic divergence from the rest of the California tiger salamander
populations. We conclude that the Sonoma County population of the
California tiger salamander is significant because the loss of the
species from the Santa Rosa Plain in Sonoma County would result in a
significant reduction in the species' range and would constitute loss
of a genetically divergent portion of the species. Because the
population segment meets both the discreteness and significance
criteria of our DPS policy, the Sonoma County population of the
California tiger salamander constitutes a DPS which qualifies for
consideration for listing. An evaluation of the level of threat to the
DPS based on the five listing factors established by the Act follows.
Previous Federal Action
On September 18, 1985, we published the Vertebrate Notice of Review
(NOR) (50 FR 37958), which included the California tiger salamander as
a category 2 candidate species for possible future listing as
threatened or endangered. Category 2 candidates were those taxa for
which information contained in our files indicated that listing may be
appropriate but for which additional data were needed to support a
listing proposal. The January 6, 1989, and November 21, 1991, NORs (54
FR 554 and 56 FR 58804, respectively) also included the California
tiger salamander as a category 2 candidate, soliciting information on
the status of the species.
On February 21, 1992, we received a petition from Dr. H. Bradley
Shaffer of the University of California, Davis (UCD), to list the
California tiger salamander as an endangered species. We published a
90-day petition finding on November 19, 1992 (57 FR 54545), concluding
that the petition presented substantial information indicating that
listing may be warranted. On April 18, 1994, we published a 12-month
petition finding (59 FR 18353) that the listing of the California tiger
salamander was warranted but precluded by higher priority listing
actions. We elevated the species to category 1 status at that time,
which was reflected in the November 15, 1994, NOR (59 FR 58982).
Category 1 candidates were those taxa for which we had on file
sufficient information on biological vulnerability and threats to
support preparation of listing proposals.
We discontinued the use of different categories of candidates in
the February 28, 1996, NOR (61 FR 7596), and defined ``candidate
species'' as those meeting the definition of former category 1. We
maintained the California tiger salamander as a candidate species in
that NOR, as well
[[Page 13502]]
as subsequent NORs published September 19, 1997 (62 FR 49398), October
25, 1999 (64 FR 57533), and October 30, 2001 (66 FR 54808).
On June 12, 2001, we received a petition dated June 11, 2001, from
the Center for Biological Diversity (CBD) and Citizens for a
Sustainable Cotati to emergency list the Sonoma County population of
the California tiger salamander as an endangered species and to
designate critical habitat. On February 27, 2002, CBD filed a complaint
for our failure to emergency list the Sonoma County population of the
California tiger salamander as endangered (Center for Biological
Diversity v. U.S. Fish and Wildlife Service (N.D.Cal.) (Case No. C-02-
0558 WHA)). On June 6, 2002, based on a settlement agreement with the
CBD, the court signed an order requiring us to submit for publication
in the Federal Register, a proposed and/or emergency rule to list the
species by July 15, 2002.
On July 22, 2002, we published in the Federal Register an emergency
rule listing the Sonoma County distinct population segment (DPS) of the
California tiger salamander (Sonoma County California tiger salamander)
on an emergency basis because we found that a number of threats
constituted immediate and significant risk to the species (67 FR
47726). We concurrently published a proposed rule to list this taxon as
endangered (67 FR 47758). The proposed rule opened a 60-day comment
period which closed on September 20, 2002. On August 26, 2002, we
published a notice in the Federal Register notifying the public of a
hearing to be held on October 1, 2002, and extending the comment period
until October 21, 2002 (67 FR 54761). On October 31, 2002, we re-opened
the comment period for 45 days (67 FR 66377). The re-opened public
comment period closed on December 16, 2002. This final rule to
designate the Sonoma County California tiger salamander as an
endangered species complies with the June 6, 2002, settlement
agreement.
As required by section 4(b)(1) of the Act, our decision to list the
Sonoma County population of the California tiger salamander is based
upon the best available information at this time. We note that the
petition and subsequent emergency listing of this population has led to
increased interest in this population by a variety of parties, and thus
to an acceleration of the rate at which new information is becoming
available. We expect this trend to continue subsequent to this final
listing determination. The settlement agreement discussed above
requires that we submit to the Federal Register a proposed rule to list
the California tiger salamander range wide by May 15, 2003, and make a
final listing determination on that proposal by May 15, 2004. As a part
of that rulemaking we intend to review all then-current information
regarding both the Sonoma County and Santa Barbara County populations,
including whether they constitute valid distinct population segments,
and render a final determination on the California tiger salamander
accordingly.
Summary of Comments and Recommendations
In the July 22, 2002, proposed rule (67 FR 47758), we requested all
interested parties submit factual reports, information, and comments
that might contribute to development of a final determination. We
contacted appropriate Federal agencies, State agencies, county and city
governments, scientific organizations, affected landowners and other
interested parties requesting comments. We published legal notices in
the Santa Rosa Press Democrat on July 29, 2002, and September 3, 2002,
and the Sonoma Index-Tribune on July 30, 2002, and September 27, 2002,
notifying the public of the comment period on the proposed and
emergency rule and the public hearing, respectively. We requested 12
peer reviewers to comment on the proposed rule in compliance with our
policy, published in the Federal Register on July 1, 1994 (59 FR
34270).
During both public comment periods, we received 111 comment letters
from public agencies, individuals, businesses, and organizations, with
several commenters submitting more than one set of comments during the
subsequent extensions of the comment period. We received oral comments
from 49 people at the public hearing. Ninety-nine commenters opposed
the listing, 60 supported the listing, and one was neutral. The
breakdown of the comments included none from Federal agencies, 2 from
State agencies, 8 from Sonoma County and city agencies, 49 from
organizations or corporations, and 99 from individuals. One hundred and
twenty people attended the hearing, with 31 individuals and 18
representatives of organizations providing oral comments. In total, 39
commenters at the hearing were opposed to the listing, 9 supported the
listing, and 1 was neutral. Several comments were received after the
comment period closed.
We updated the final rule to reflect comments and information we
received during the comment periods. We address substantive comments
concerning the rule below. Comments of a similar nature are grouped
together (referred to as ``Issues'' for the purpose of this summary).
Issue 1: Some commenters questioned the validity of our DPS
determination for Sonoma County California tiger salamander, suggesting
that the genetic data do not support a DPS. One commenter specifically
suggested that the evidence that Sonoma County California tiger
salamander is a separate species or subspecies and use of this as a
criterion for a DPS is less clear than we indicated in our emergency
rule. The commenter also suggests that there is little evidence that
California tiger salamander populations in different parts of
California represent separate species or subspecies. The commenter also
noted that, while the unpublished Shaffer et al. (1993) suggest Sonoma
County may warrant species status, Shaffer and McKnight (1996) make no
such claim in their published paper.
Response: Genetic distinctness or the presence of genetically
determined traits may be important in recognizing some DPS's, but this
kind of evidence is not specifically required in order for a DPS to be
recognized. Genetic information can play two different roles in the
evaluation of whether a population should be recognized as a distinct
vertebrate population segment for the purposes of listing under the
Act. First, quantitative genetic information may, but is not required
in order to provide evidence that the population is markedly separated
from other populations and thus meets the DPS policy's criterion of
being discrete. The DPS policy's standard for discreteness is meant to
allow an entity given DPS status under the Act to be adequately defined
and described. The standard adopted is believed to allow entities
recognized under the Act to be identified without requiring an
unreasonably rigid test for distinctness. At the same time, the
standard does not require absolute separation of a DPS from other
members of its species, because this can rarely be demonstrated in
nature for any population of organisms. Second, genetic characteristics
that differ markedly from other populations may be one consideration in
evaluating the discrete population segments biological and ecological
significance to the taxon to which it belongs.
Restricting listings to full taxonomic species would render the
Act's definition of species, which explicitly includes subspecies and
DPS's of vertebrates, superfluous.
[[Page 13503]]
We did note in our emergency rule that Dr. Shaffer and his
colleagues believe the divergence of Sonoma County California tiger
salamanders justifies separate species recognition (Shaffer et al.
1993). Our DPS policy (61 FR 4722), however, does not require that
levels of differentiation warranting taxonomic revision be identified
for the DPS criteria to be met. In fact, our DPS policy is used for
identifying groups within species or subspecies that may warrant
listing under the ESA. Therefore, our DPS determination for Sonoma
County California tiger salamander is not based on whether the
divergence observed warrants separate taxonomic recognition, but rather
on the relatively high divergence of the Sonoma County population from
other populations of California tiger salamanders.
The Sonoma County population of California tiger salamanders is the
most divergent of any population of the species. This finding is
supported by the original mitochondrial DNA (mtDNA) work of Shaffer et
al. (1993) and by additional sampling and mtDNA work of Shaffer and
Trenham (2002). The ``first, deepest and most significant phylogenetic
split within California tiger salamander samples is between Sonoma
County and all others'' (H.B. Shaffer, in litt., 2002). This is
illustrated by the phylogenetic tree based on mtDNA in which Sonoma
County California tiger salamander is the first branch after the
outgroup (Shaffer and Trenham 2002). This branch is strongly supported
statistically (with bootstrap probability of 100 percent) on a
phylogenetic tree constructed by the neighbor joining (NJ) method.
Seventy percent is the normal criterion for statistical significance of
bootstrap proportions in the systematic literature (Hillis and Bull
1993 as cited in Shaffer and McKnight 1996). In addition, the branch
pattern indicating that the Sonoma County population is distinct is
supported by maximum likelihood and parsimony (Shaffer and Trenham
2002), two other methods of constructing phylogenetic trees (Avise
1994, Weir 1996). In addition, Shaffer and Trenham (2002) report
preliminary results of analyses of two nuclear genes. These preliminary
results also show that Sonoma County California tiger salamanders are
genetically distinct from other California tiger salamanders.
Therefore, we believe that the levels of divergence observed in Sonoma
County California tiger salamanders provide substantial evidence of the
significance of the population.
Shaffer and McKnight (1996) do not mention whether the divergence
of Sonoma County California tiger salamanders justifies separate
species recognition. They make no statements about the taxonomic status
of Sonoma County California tiger salamanders in their paper. In the
Discreteness section of the emergency rule, we incorrectly attributed
the statement that Sonoma County California tiger salamanders warrant
separate taxonomic recognition to the 1996 publication. In fact, no
Sonoma County California tiger salamanders were sampled in the study
(Appendix 1 of Shaffer and McKnight 1996). The paper examined
evolutionary relationships among tiger salamander species and
subspecies and did not include a formal taxonomic treatment of the
tiger salamander complex. Therefore, it is not surprising that the
authors did not specifically note whether or not the divergence of
Sonoma County California tiger salamanders justifies species status.
Issue 2: One commenter also implied that the discreteness criterion
of our DPS policy was only met by genetic data.
Response: Two professional biologists who commented reported that
the Sonoma County population is geographically isolated from other
populations of the California tiger salamander. We note that the
proposed rule discussed the geographic separation of the Sonoma County
population from other populations of California tiger salamander. The
Sonoma County population is separated from other California tiger
salamander populations by the Coast Range, Napa River, and the
Carquinez Straits, a distance of about 72 km (45 mi).
Issue 3: Some commenters felt that 2 percent divergence of the
Sonoma population of the California tiger salamander from the remainder
of the California tiger salamander population is not meaningful or
worthy of recognition as a DPS.
Response: We note that species boundaries are typically identified
by systematists using phylogenetic analysis rather than absolute levels
of sequence divergence. The intraspecific sequence divergence value of
2 percent depends on the total number of nucleotides sequenced for each
gene region. This can differ significantly from species to species or
from study to study and is therefore a relative value (Avise 1994, Weir
1996, Hedrick 2000). Comparisons need to be made from the same
baseline. From a DPS perspective, percent sequence divergence is less
important than the phylogenetic relationships depicted with strong
statistical support in the neighbor joining (NJ) tree that indicate the
distinctive genetic character of Sonoma County California tiger
salamanders. The phylogenetic tree (which indicates relationships among
populations or groups) constructed from the mtDNA data of Shaffer and
Trenham (2002) indicates that Sonoma County California tiger
salamanders are very distinct relative to other California tiger
salamanders, and separated from them on a branch that is strongly
supported statistically. Therefore, the most comprehensive available
genetic data (Shaffer and Trenham 2002) for California tiger
salamanders strongly indicate that Sonoma County California tiger
salamanders are distinct from other populations of the species.
Issue 4: One commenter analyzed Shaffer and McKnight's (1996)
divergence values for various Ambystoma tigrinum subspecies and for
California tiger salamander, finding that divergence between
populations in different groups (e.g., between California tiger
salamander and A. tigrinum subspecies and other such combinations among
species and subspecies versus within a species or subspecies) had a
mean of 6.37 percent and a range of 5.08 percent to 7.41 percent. The
commenter states that these statistics show the 2 percent divergence of
the Sonoma County California tiger salamander population is
unremarkable.
Response: As noted above, one way to meet the significance
criterion of our DPS policy (61 FR 4722) is for a population to
``differ markedly from other populations of the species in its genetic
characteristics'' (emphasis added). We note again that our DPS policy
focuses on differentiation within species (i.e., the population
``differs markedly from other populations of the species''). The
commenter's analysis is of differences among taxonomic groups of tiger
salamanders, not of within-species or subspecies differences, which are
the focus of the DPS policy.
As explained above, we believe the available mtDNA data (Shaffer et
al. 1993, Shaffer and Trenham 2002) show that the Sonoma County
population of California tiger salamander is markedly genetically
divergent from other populations of the California tiger salamander.
That the sequence divergence value is 2 percent is less important than
the configuration of the phylogenetic tree, which strongly supports the
distinctness of Sonoma County California tiger salamanders.
Issue 5: One commenter stated that one would expect broadly similar
conclusions from allozyme and mtDNA studies and that for Sonoma County
California tiger salamanders this was not the case. The commenter noted
that
[[Page 13504]]
Shaffer et al.'s (1993) allozyme work did not reveal much variation
(only 9 of 26 loci were variable) and indicate that Sonoma County
California tiger salamanders are not distinct from other western
populations of California tiger salamander from Yolo County to San Luis
Obispo County.
Response: A variety of genetic tools are available to assess
genetic variation. These tools are often referred to as ``genetic
markers.'' All are indicators of genetic variation, but none is
considered determinative. Which genetic marker is most useful depends
on the question being asked and the organism being studied (Haig 1998,
Parker et al. 1998).
Allozymes are proteins which are used as genetic markers because
DNA contains information that is used by cells to build protein.
Allozymes have been used to assess genetic variation for many years.
Allozyme studies have the advantage of being relatively inexpensive and
straightforward, once the basic technique is developed for a group.
However, drawbacks of using allozymes include the limited number of
proteins that can be screened (Parker et al. 1998) and the fact that
they often detect little variability (Haig 1998). On average across
taxa, less than half of all loci are variable. It is not uncommon for
population biologists to encounter species for which allozymes cannot
be used as genetic markers because they lack variation (Parker et al.
1998).
Molecular techniques, such as mtDNA, allow biologists to examine
variation in DNA directly, rather than looking at the product derived
from DNA (i.e., proteins) (Parker et al. 1998). Analysis of animal
mtDNA is the most commonly used technique for examining phylogenetic
relationships among populations of the same species and among closely
related species (Taberlet 1996). One advantage of mtDNA in particular
is its high rate of evolution (i.e., rate of nucleotide substitution)
compared to other DNA (Taberlet 1996, Parker et al. 1998). The D-loop
(which Shaffer and colleagues examined for their tiger salamander
studies) is especially variable, making it useful to study recently
divergent populations or species. Different genetic techniques are
expected to resolve different amounts of variation because the genetic
markers used have different evolutionary characteristics (Parker et al.
1998). The observation that some characters (in this case, allozymes)
are not variable does not diminish the utility of other data (in this
case mtDNA) in describing relationships among groups.
Issue 6: Several commenters felt that our finding that California
tiger salamanders in Sonoma County qualified as a DPS was based on an
isolated, and dated, report (i.e., Shaffer et al. (1993). One commenter
noted several times that Shaffer et al. (1993), the source of mtDNA
data for California tiger salamanders, is an unpublished report.
Response: We are required to use the best available scientific
data. In this case, the data were in an unpublished report. During the
comment period, we received a second report (Shaffer and Trenham 2002)
that contained findings similar to Shaffer et al. 1993 but which was
based on more extensive data collection. The publication of Shaffer and
McKnight (1996) using mtDNA techniques for California and other tiger
salamanders and the publication of mtDNA work by Shaffer et al. (2000)
on Yosemite toad (Bufo canorus) gives us confidence that Shaffer's work
is scientifically defensible.
Issue 7: Several commenters noted that recent aerial photos and a
map that is based on the photos show 515 or more pools located within,
or in the vicinity of, the Santa Rosa Plain. They believe these could
potentially provide habitat for the Sonoma County California tiger
salamander. They stated that many of the pools have not been surveyed
and, therefore, the species could be more widespread in Sonoma County
than is currently known.
Our Response: The map submitted displayed 515 water bodies and was
based on interpretation of aerial photography with little on-the-ground
verification. We compared the map of potential habitat for the
California tiger salamander to information and data we obtained and
have determined 360 water bodies can be eliminated as potential habitat
for the California tiger salamander due to a variety of factors
including: unsuitable soils, unsuitable vegetation, high elevation,
presence of aquatic predators, agricultural development (row crops,
vineyards, etc.), urbanization, and unsuitable hydrology. One hundred
and fifty-five water bodies remained within the suitable habitat area.
Of the 155 remaining water bodies, 53 were characterized as ``man-
made long'' and ``natural long'' ponds/wetlands, which hold water for
too long and /or harbor aquatic predators, and were eliminated as
potential habitat for the California tiger salamander. Another set of
water bodies were ``man-made short'' and ``natural short'' ponds/
wetland (12 in total) which do not hold water long enough to be a
source of potential habitat for the California tiger salamander.
Consequently only ``man-made moderate'' and ``natural moderate'' mapped
water bodies were considered potential suitable habitat (90 in total).
Of the ``man-made moderate'' and ``natural moderate'' mapped water
bodies, four were formerly known breeding sites that have been
eliminated and eight are currently identified as existing breeding
sites. Some of the mapped water bodies are anticipated to have aquatic
predators given their location on the Laguna de Santa Rosa floodplain,
which would limit California tiger salamander utilization. Others
contain habitat with sightings near the ponds, but these ponds have
been repeatedly surveyed by experts, with results indicating they do
not support breeding populations of California tiger salamanders.
The determination that some of the mapped water bodies contain
potential habitat is solely based on aerial photographs; however, the
majority of these are on private property and inaccessible to surveying
without landowner permission. Several recognized salamander biologists
have conducted repeated road surveys in Sonoma County along areas where
the California tiger salamander is known to exist or where suitable
habitat appears to exist (D. Cook, The Wildlife Society, pers. comm.,
2002; P. Northen, California State University, Sonoma, pers. comm.,
2002; J. Seifers, Santa Rosa, California, per. comm., 2002; H. B.
Shaffer, pers. comm., 2002; P. C. Trenham, UCD, pers. comm., 2002).
Night driving is a standard technique for surveying for reptiles and
amphibians (Shaffer and Juterbock 1994; Parris 1999). The locations
where these biologists found breeding sites, migrating adult
salamanders, subadults, larvae, and egg masses in roadside ditches were
entered into the CNDDB. This data is considered essential (D. McGriff,
CDFG, pers. comm., 2002) and the data was utilized in our analysis of
the status of the California tiger salamander in Sonoma County. Several
of the experts indicated that there are likely to be a few small
breeding sites or potential habitat for California tiger salamanders on
private lands containing grassland areas and suitable soils on the
Santa Rosa Plain, including stock ponds (P. Northen, pers. comm., 2002;
H. B. Shaffer, pers. comm., 2002; P. C. Trenham, pers. comm., 2002);
however, these private lands were inaccessible during their survey
efforts.
Issue 8: One commenter believed that two sites not specifically
mentioned in the proposed rule should be included as breeding sites for
California tiger salamanders.
[[Page 13505]]
Our Response: We evaluated the two sites mentioned by the
commenter. They are the Hartunian (Scenic Avenue) Preserve and the
Southwestern Santa Rosa Vernal Pool Preservation Bank (Engel Bank).
The Hartunian Preserve is approximately 14 hectares (ha) (34 acres
(ac)) in size and has one shallow swale that could support successful
breeding during a rainy season of above-average rainfall. This preserve
was not listed in the emergency rule and has not been included in the
final rule because breeding by the species is not likely to occur
during years of low to average rainfall.
Upon review of all information available, we have concluded that
the Engel Bank does meet the biological requirements for California
tiger salamander breeding and we have included this site as an eighth
breeding site. Engel Bank is a 16-ha (40-ac) preserve that contains
approximately 7-ha (18-ac) of wetlands and has documented records of
the species. However, California tiger salamanders require a fairly
large upland component. Approximately 9 ha (22 ac) of protected uplands
are available at this site. Therefore, due to the limited upland
habitat protected within the Engel Bank, a sustainable population at
this site is dependent on the activities occurring on the surrounding
private property.
Issue 9: Many commenters stated that the California tiger
salamander is adequately protected by current regulations. Examples of
current regulations cited include the application of the Porter-Cologne
Water Quality Control Act and the California Environmental Quality Act
(CEQA) by CDFG. Both of these require one-to-one mitigation for
projects impacting the species. Commenters also mentioned strict local
land use controls enacted by Sonoma County and cities within the Santa
Rosa Plain. In addition, commenters noted that the Sonoma County
Agricultural and Open Space District has acquired potential California
tiger salamander habitat that is set aside as open space through a
county-wide sales tax. They felt these preserves are adequate for the
animal. Several other commenters stated that current legal protections
have been inadequate for the species, and losses of breeding sites have
occurred.
Our Response: CDFG lists the California tiger salamander as a
species of special concern and has no specific regulatory mechanism to
require mitigation for impacts to this species. In some instances, the
CDFG has obtained one-to-one mitigation for destruction of California
tiger salamander breeding sites. However, five breeding sites have been
eliminated in Sonoma County during the past 2 years without new
breeding sites being created. The use of CEQA and the Porter-Cologne
Water Quality Control Act have not halted the loss of habitat for this
species in Sonoma County. The land use controls enacted by the County
and cities have not required adequate compensation for the loss of
breeding sites. The Sonoma County Agricultural and Open Space District
has acquired acreage through a one-quarter of a cent county sales tax.
However, the acreage purchased does not overlap with areas known to
contain California tiger salamander breeding sites. A majority of their
purchased lands lie outside of the Santa Rosa Plain. Of the lands they
have purchased within the Santa Rosa Plain, the majority fall within
the floodplain of the Laguna de Santa Rosa River. There are no known
records of the California tiger salamander within this 100 year
floodplain.
Issue 10: Many commenters stated that the comment period did not
allow sufficient time for meaningful public input. A number of them
said that more time was needed to complete surveys that currently are
underway.
Our Response: The comment period for the proposed rule was
initially open for 60 days, closing on September 20, 2002. On August
26, 2002, the comment period was extended until October 21, 2002. The
comment period was re-opened on October 31, 2002, for an additional 45
days. In total, the comment period was open for 145 days.
At least 12 surveys are ongoing in Sonoma County in three areas not
previously known to have California tiger salamander occurrences, and
to date, there have been no detections of the animal. We agree that
additional survey information is valuable. However, the Service has not
had the flexibility to wait until surveys are finished because an
order, issued by the district court in Center for Biological Diversity
v. U.S. Fish and Wildlife Service, required us to complete this rule
before the expiration of the protection afforded the DPS by the
emergency rule.
Issue 11: One commenter stated that we should extend the comment
period because we had not made available to the public documents on
which the emergency listing and permanent listing was based.
Our Response: As stated in the emergency rule, the complete file
for the rule is available for inspection, by appointment, during normal
business hours at the Sacramento Fish and Wildlife Office. In addition,
the proposed rule stated that all comments received during the comment
period were available for public review. The complete file for this
rule is available for inspection, by appointment, during normal
business hours at the Sacramento Fish and Wildlife Office.
Issue 12: Several commenters felt we should complete peer review
and incorporate that analysis into a proposed rule.
Our Response: In accordance with our July 1, 1994, Interagency
Cooperative Policy for Peer Review in Endangered Species Act Activities
(59 FR 34270), we solicited review from 12 experts in the fields of
ecology, conservation, genetics, taxonomy and management. The purpose
of such a review is to ensure that listing decisions are based on
scientifically sound data, assumptions, and analyses, including input
from appropriate experts. The five peer reviewers who sent comments
supported listing of the Sonoma County California tiger salamander.
They provided additional documentation on the distribution, genetics,
and threats to the species. This information has been incorporated into
this final rule.
Issue 13: Numerous commenters felt the proposal to list the Sonoma
County California tiger salamander was based on one study conducted by
a group with a very specific agenda against property rights and
development. They said listing decisions should be based on specific
studies by non-partisan professionals. Two commenters felt that the
proposed rule was based on inaccurate or incomplete data. Numerous
commenters felt the data we utilized on the California tiger salamander
was at least 10 years old and was thus not current or accurate. One
recognized herpetologist provided additional peer-reviewed articles on
the California tiger salamander from scientific journals. Another
professional biologist noted the proposed rule was based on research
conducted as recently as 2001 by knowledgeable herpetologists.
Our Response: We used the best scientific and commercial
information available during the status review process and preparation
of the emergency and final rules to make our listing determination. We
utilized museum records; CNDDB information; aerial photographs
documenting the land use changes over the last 60 years; reports
produced by the Sonoma County Agricultural Commissioners and the Sonoma
County Planning and Development Department; unpublished reports by
biologists; and peer-reviewed articles from scientific journals in
making that determination.
[[Page 13506]]
Out of 126 citations appearing in the emergency rule, 52 have been
published within the past 5 years (41 percent) and 83 citations have
been published within the past 10 years (66 percent). The initial
report on the population genetics of the California tiger salamander by
Shaffer et al. (1993) has been substantiated by additional research
(Barry and Shaffer 1994; Fisher and Shaffer 1996; Shaffer and McKnight
1996; Cook and Northen 2001; Shaffer and Trenham 2002).
Issue 14: Some commenters felt we had not quantified the magnitude
of loss of the California tiger salamander in Sonoma County. One
herpetologist said we had presented accurate information on the status
of the species in Sonoma County.
Our Response: Based on the best available scientific and commercial
information, five breeding sites for the California tiger salamander in
Sonoma County have been destroyed in the past 2 years, and there are
only eight known breeding sites remaining. Five of these sites are on
private lands with no effective regulatory protection. Only one of the
three protected sites is over 32 ha (80 ac) in size. All known breeding
sites in the Cotati area have now been destroyed. The remaining sites
in the Cotati area where the animals can mate and develop are roadside
ditches and other suboptimal habitat during years of above average
rainfall.
Issue 15: According to some commenters, there has been no study to
determine population trends or ways to improve breeding at the known
preserves containing the California tiger salamander.
Our Response: All of the three protected sites known to contain
salamanders have been surveyed for the past 4 years. All surveys at
these sites have resulted in the detection of very low numbers of
salamander larvae during years that they were found at all. The largest
preserve is approximately 81 ha (200 ac) in size, yet continues to
exhibit very low numbers of larvae as indicated by yearly surveys. It
is probable that salamander populations are limited by the lack of
uplands for estivation during the dry season.
Issue 16: A number of commenters asked us to delay a final listing
decision until a full review of the scientific evidence supporting or
disputing the status of the Sonoma County California tiger salamander
had been presented in a public forum.
Our Response: The purpose of publishing a proposed rule and
soliciting public input during the comment period is to fully involve
the public in the listing process. We also held a workshop and public
hearing in Santa Rosa, California, to encourage agency and public input
into the review of the proposed rule. We solicited 12 recognized
experts and specialists to review the proposed rule. We utilized this
information in making the final determination.
Issue 17: Numerous commenters said the listing of the California
tiger salamander would have a severe economic impact on Sonoma County.
They said we should complete an analysis of the economic effects of
listing and include it in the final rule.
Our Response: Under section 4(b)(1)(A) of the Endangered Species
Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.), we must base a
listing decision solely on the best scientific and commercial data
available. The legislative history of this provision clearly states the
intent of Congress to ensure that listing decisions are ``* * * based
solely on biological criteria and to prevent non-biological criteria
from affecting such decisions* * * '' (House of Representatives Report
Number 97-835, 97th Congress, Second Session 19 (1982)). As further
stated in the legislative history, ``* * * economic considerations have
no relevance to determinations regarding the status of species * *
*''(Id. at 20). Therefore, we did not consider the economic impacts of
listing the Sonoma County California tiger salamander.
Issue 18: Two commenters stated that critical habitat has not been
proposed and, therefore, the listing is in violation of the Act.
Our Response: Pursuant to section 4(a)(3) of the Act, we have
determined that designation of critical habitat is prudent for the
Sonoma County California tiger salamander (see the ``Critical Habitat''
section). However, our budget for listing activities is currently
insufficient to allow us to immediately complete all the listing
actions required by the Act. Listing the DPS without designating
critical habitat at this time allows us to provide protections needed
for the conservation of the species without further delay. This is
consistent with section 4(b)(6)(C)(i) of the Act, which states that
final listing decisions may be issued without critical habitat
designations when it is essential that such determinations be promptly
published. We will prepare a critical habitat designation in the future
when our available resources allow.
Issue 19: One commenter said the 1995 Santa Rosa Plain Vernal Pool
Ecosystem Preservation Plan indicated the Sonoma County California
tiger salamander is potentially less vulnerable than stated in our
proposed rule.
Our Response: The Santa Rosa Plain has experienced rapid urban
growth since the vernal pool ecosystem preservation plan was issued in
1995. From 1995 until 2001, the population of Sonoma County increased
by approximately 10% with an average annual growth rate of
approximately 1.6 percent. (U.S. Census Bureau; California Department
of Finance; California Association of Realtors website 2002). Increases
in housing, traffic, industry, and office buildings have occurred
concurrent with the increase in population growth. In the past 2 years,
five breeding sites for the Sonoma County California tiger salamander
have been destroyed. Loss of real and potential salamander breeding
sites and estivation habitat continues to occur in the Santa Rosa
Plain. Given the amount of habitat loss, inadequate regulatory
mechanisms, and other threats, we believe the remaining California
tiger salamanders in Sonoma County are endangered.
Issue 20: Several commenters stated that we should compensate
private landowners for the loss of revenue that occurs when California
tiger salamanders are found on their land. Another commenter said the
``Cattle Growers'' ruling prohibits us from imposing land use
restrictions predicated upon listing except through a designation of
critical habitat, and not doing so constitutes unlawful taking of
property without compensation.
Our Response: The presence of an endangered or threatened species
does not prevent all uses of public or private lands. The listing of a
species does not impose land use restrictions and, therefore, does not
result in unlawful taking of property. In addition, we will assist
landowners in the identification of proposed activities that could
result in take (harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect, or to attempt to engage in any such conduct),
develop measures to minimize the potential for take, and work with them
to obtain authorizations for incidental take through sections 7 and 10
of the Act. Recovery planning for this species may include
recommendations for land acquisition or easements involving private
landowners. Any such efforts will be undertaken with the full
cooperation of the landowners.
A recent case pertinent to this issue, Arizona Cattle Growers v.
Fish and Wildlife and Bureau of Land Management (9th Circuit Court of
Appeals 99-16102), provides that, in
[[Page 13507]]
biological opinions issued pursuant to section 7 of the Act, the terms
and conditions in a biological opinion must have an articulated,
rational connection to the take of a listed species. The court stated
that the Act provides for the designation of critical habitat outside
the geographic range currently occupied by a listed species when ``such
areas are essential for the conservation of the species.'' Absent this
procedure, the court stated that there is no evidence that Congress
intended to allow the Service to regulate any parcel of land that is
merely capable of supporting a listed species. Therefore, the mere
listing of species, such as the Sonoma County California tiger
salamander, will not result in land use restrictions.
Issue 21: One commenter was concerned that existing vineyards and
wineries would be burdened by excessive costs when water permits are
required or changed, or when planting or replanting permits are
requested.
Our Response: Once a species becomes listed, section 9 of the Act
sets forth a series of general prohibitions that apply to that species.
The Sonoma County California tiger salamander is protected from
``take'' by any person subject to the jurisdiction of the United
States. The definition of take under the Act includes harass, harm,
pursue, hunt, shoot, wound, kill, trap, capture, collect, or attempt to
engage in any such conduct. Harm is further defined to include
significant habitat modification or degradation that results in death
or injury to the listed wildlife by significantly impairing behavioral
patterns such as breeding, feeding, or sheltering. Harass is further
defined to include actions that create the likelihood of injury to
listed wildlife by annoying it to such an extent as to significantly
disrupt normal behavior patterns which include, but are not limited to,
breeding, feeding, or sheltering. Therefore, if the action by a party,
such as water use by a vineyard or winery, planting or replanting of
vineyards, could result in ``take'' of a listed species, then
authorization for incidental take should be obtained pursuant to either
sections 7 or 10 of the Act.
Issue 22: One commenter felt that the CDFG considered the emergency
listing inappropriate due to a lack of proper information and
sufficient scientific support.
Our Response: Only species or subspecies, and not distinct
population segments, of vertebrates can be listed as endangered or
threatened under the California Endangered Species Act (California
Department of Fish and Game internet web site 2003). However, the
California Department of Fish and Game has expressed concern for
adverse impacts to the salamander and its habitat (R. Floerke, CDFG, in
litt., 2002).
Issue 23: One commenter stated that the breeding sites identified
in the emergency rule for the Sonoma County California tiger salamander
are not threatened, and the sites around the old airfield would not be
destroyed because construction will avoid them and be limited to the
runway. The commenter also felt the degree of threat, isolation of
habitats, and barriers to movement were overstated and not based in
reality. This same commenter believed that the Roseland Creek channel
and asphalt run-way already constitute a significant barrier to
migrating salamanders at the old airfield. Several other commenters
noted the vernal pools at the Southwest Air Center (Air Center) have
been damaged, destroyed, or are currently on the verge of being lost.
Our Response: Other than approximately 28 ha (70 ac) designated as
open space, the remainder of the Air Center has been designated for
development in the Southwest Santa Rosa Area Development Plan. One of
the breeding sites could be destroyed by development and two others
could be isolated and imperiled by a loss of estivation habitat. Upon
development of this area, not enough upland will likely remain to
support a viable salamander population even if two of the three
breeding sites are not destroyed. Proposed development could also
isolate the Federal Emergency Management Agency (FEMA)/Broadmore North
Preserves.
Burrowing mammals also could be increasingly subject to control
actions given the proximity of developed areas to any remaining
estivation habitats. One proposed development project at the Air Center
could fill two wetlands that make up one of the eight known breeding
sites. Surveys of this site over the past 2 years have found breeding
California tiger salamanders. Construction on the runway itself and
extension of Fresno Avenue could result in total isolation of the FEMA/
Broadmore North Preserves, a known Sonoma County California tiger
salamander breeding site. We have determined that Roseland Creek
Channel is not likely to be a barrier to salamander migration. Flows in
the channel are minimal, except during the heaviest of rain events.
Issue 24: One commenter felt that the emergency rule overstated the
effects of development at the Air Center because the runways are too
hot for salamanders to cross.
Our Response: Hot runways are not a concern for this species
because California tiger salamanders are in estivation during the dry,
hot, summer months. The nocturnal adult animals concentrate their
movements during rain events in the cooler fall, winter, and spring
months. Researchers conducting night-time road surveys for California
tiger salamanders during the fall, winter, and spring have documented
this species crossing roads on many occasions.
Issue 25: One commenter stated that California tiger salamanders
exist in the Central Valley and coastal areas of California and,
therefore, they could not be endangered.
Our Response: Research has indicated there are six populations of
California tiger salamanders occurring in California. These include the
Santa Rosa area of Sonoma County; the Bay Area (central and southern
Alameda, Santa Clara western Stanislaus, western Merced, and the
majority of San Benito counties); Central Valley (Yolo, Sacramento,
Solano, eastern Contra Costa, northeast Alameda, San Joaquin,
Stanislaus, Merced, and northwestern Madera counties); southern San
Joaquin Valley (portions of Madera, central Fresno, and northern Tulare
and Kings counties); Central Coast Range (southern Santa Cruz,
Monterey, northern San Luis Obispo, and portions of western San Benito,
Fresno, and Kern counties); and Santa Barbara County (Shaffer and
Trenham 2002). The Sonoma County population meets the requirements of
our Distinct Population Segment policy and therefore can be separated
from the remainder of the population in making this determination.
Issue 26: One commenter stated that much of the area defined as
potential range of the Sonoma County California tiger salamander was
based on soil types.
Our Response: The distribution of the Sonoma County California
tiger salamander corresponds to the distribution of specific soil
types. The known breeding sites of the animal in Sonoma County are
restricted to Huichica-Wright-Zamora and Clear Lake-Reyes soils series/
associations as defined by the USDA (1972, 1990). The poorly drained
soils in the Huichica-Wright-Zamora association are considered prime
soils for containing wetlands, and more specifically, prime soils for
habitat containing California tiger salamander (P. Northen, pers.
comm., 2002). The Huichica-Wright-Zamora association is restricted to
the Santa Rosa Plain and the vicinity of the town of Sonoma (USDA 1972,
1990). The poorly drained soils in the Clear
[[Page 13508]]
Lake-Reyes association are considered suitable to marginal soils for
containing wetlands or habitat for California tiger salamander (P.
Northen, pers. comm., 2002). The Clear Lake-Reyes association is found
from the Cotati region south and east of Petaluma to the tidelands of
northern San Francisco Bay where the salt marsh habitat is unsuitable
for the California tiger salamander. There are also scattered areas of
the Clear Lake-Reyes association found south and southwest of the town
of Sonoma (USDA 1972, 1990). There are no known records of the
California tiger salamander from the area around the town of Sonoma (D.
McGriff, pers. comm., 2002), and there is now extensive urban and
agricultural development in this portion of the county.
Peer Review
In accordance with our July 1, 1994, Interagency Cooperative Policy
for Peer Review in Endangered Species Act Activities (59 FR 34270), we
solicited the expert opinions of 12 independent specialists regarding
pertinent scientific or commercial data and assumptions relating to the
taxonomy, population status, and supporting biological and ecological
information for the California tiger salamander in Sonoma County. The
purpose of such review is to ensure that listing decisions are based on
scientifically sound data, assumptions, and analyses, including input
of appropriate experts and specialists. Information and suggestions
provided by the reviewers were incorporated or addressed as applicable.
We received peer reviews from five of the experts. All of them
agreed the Sonoma County California tiger salamander is imperiled
throughout all or a portion of its range. One reviewer provided
references on threats from disease the reviewer believed relevant to
our final rule decision. This peer reviewer also stated that threats
from disease are much more severe for small populations. Another peer
reviewer recommended a number of editorial clarifications in the
emergency and proposed rules. The third peer reviewer stated that the
California tiger salamander should be listed throughout its range. A
fourth peer reviewer provided additional information on the California
tiger salamander, and the fifth peer reviewer, based on years of field
work, agreed that the Sonoma County California tiger salamander is
endangered.
Summary of Factors Affecting the Species
Section 4 of the Act and regulations (50 CFR part 424) promulgated
to implement the listing provisions of the Act describe the procedures
for adding species to the Federal list. We may determine a species to
be endangered or threatened due to one or more of the five factors
described in section 4(a)(1). These factors, and their application to
the Sonoma County California tiger salamander, are as follows:
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
The Sonoma County California tiger salamander population, as well
as the population in Santa Barbara County, which we listed as
endangered (65 FR 57242, September 21, 2000), are considered to be the
most vulnerable of the six populations of the California tiger
salamander (LSA Associates, Inc. 2001; Shaffer and Trenham 2002). Urban
development is the primary threat to the Sonoma County California tiger
salamander. The DPS now occurs in scattered, and increasingly isolated,
breeding sites within a small portion of its historic range on the
Santa Rosa Plain in Sonoma County. Five known breeding sites of this
DPS have been destroyed in the last 2 years. All of the eight known
remaining breeding sites are distributed in the City of Santa Rosa and
immediate associated unincorporated areas, an area approximately 8 km
(5 mi) long by 6 km (4 mi) wide. Within this area and south to the
Cotati area, there are scattered records of adult salamanders crossing
roads during the fall and winter rains, and also sporadic instances of
breeding in roadside ditches and low-quality pools. However, these
roadside ditches and low-quality pools likely do not represent viable
breeding sites because they either do not have sufficient ponding
duration and/or associated uplands for estivation.
The eight known breeding sites are imperiled by the construction of
high-density housing, office buildings, roads, and other development.
The survival and viability of the Sonoma County California tiger
salamander is directly related to availability of breeding pools with
hydrological and other factors conducive to the salamander's
reproduction. There also must be adequate upland acreage, with
associated small mammal burrows, in the vicinity of the Sonoma County
California tiger salamander breeding pools to accommodate estivation.
The Santa Rosa Plain once contained extensive valley oak woods, native
grasslands, riparian, and vernal pools (1942 aerial photographs on file
with Dr. Phil Northen at California State University at Sonoma). Vernal
pools and seasonal wetlands likely were extensive, due to the flat
terrain, clay soils, and relatively high rainfall (CH2M Hill 1995).
Based on the topography and habitat type of the lands that have been
converted to urban development and agriculture on the Santa Rosa Plain,
the number of breeding ponds, the extent of upland habitats, and the
quality of the remaining habitats has been greatly reduced since
Europeans first settled the region.
The extent of the historic range of the California tiger salamander
within the Santa Rosa Plain in Sonoma County is uncertain due to
limited information collected on this population prior to the 1990s
(Shaffer et al. 1993; Jennings and Hayes 1994). However, based on the
habitat requirements of the species for low elevation, seasonally
filled breeding ponds and small rodent burrows, the ecology of the
taxon, the general trend of urban development into suitable and
occupied habitat, and other adverse factors affecting the species, we
believe that it once occupied a more extensive, but still limited area
within the Santa Rosa Plain.
A 1990 study of the Santa Rosa Plain found that 25 percent of an
11,300-ha (28,000-ac) study area had been converted to subdivisions,
``ranchettes,'' golf courses, and commercial buildings (Waaland et al.
1990). An additional 17 percent of the study area had been converted to
agricultural uses. Since 1990, many more acres have been urbanized and
converted to intensive agriculture, particularly vineyards. Even
relatively minor habitat modifications, such as construction of roads,
storm drains, and road curbs that traverse the area between breeding
and estivation sites, increase habitat fragmentation, impede or prevent
migration, and result in direct and indirect mortality of California
tiger salamanders (Mader 1984; S. Sweet, in litt. 1993, 1998; Findlay
and Houlahan 1996; Launer and Fee 1996; Gibbs 1998). All of the
remaining known Sonoma County California tiger salamander breeding
pools are within 450 m (1,476 ft) of roads and residential development,
and five of the eight remaining viable breeding locations are within
100 m (328 ft) of major development activities.
Urban Development
Urban development poses a significant threat to all of the known
breeding sites of the Sonoma County California tiger salamander. Six of
these
[[Page 13509]]
sites are found in and around the former Air Center that is located in
southwest Santa Rosa. This area contains one of the largest undeveloped
blocks of land within the city limits of Santa Rosa. Urban development
is proposed on or near locations containing four of the eight known
breeding sites in the Santa Rosa area (EIP Associates 1994, 2000). The
airport was closed and the property sold to the City of Santa Rosa in
the mid-1980s. The City of Santa Rosa is proposing the majority of the
area be developed as part of their Southwest Area Plan (EIP Associates
1994, 2000).
Urban development of the Santa Rosa area is proceeding rapidly.
Demographic data obtained from the City of Santa Rosa Housing and
Community Development Commission indicate that, since 1980, Santa Rosa
has experienced a greater than 53 percent increase in its population.
From 1980 until 1997, the number of housing units grew by 66 percent
from 35,403 units in 1980 to 53,558 units by January 1, 1997 (M.
Enright, pers. comm., 2001).
Five known breeding sites were lost within the past 2 years, two of
which were lost due to commercial development with another lost to
urban development/housing. In June 2002, a fourth breeding site near
Cotati was destroyed when the pond was filled for unknown reasons (D.
Cook, in litt., 2002; L. Davis, pers. comm., 2002). The Cotati location
was considered highly productive for salamanders (D. Cook, in litt.,
2002). A fifth, and previously unknown, breeding site near Cotati was
destroyed shortly after the emergency listing went into effect (67 FR
47726) (D. Wooten, Service, pers. comm., 2002). We were not aware of
this occurrence at the time the emergency rule was published.
Salamander larvae were found in a roadside ditch that backed up onto a
large pool on private property (CNDDB 2002). It is likely this pool
served as the breeding site for salamanders in this area. This site was
located in an area where road sightings of tiger salamanders commonly
occurred in absence of a known breeding site. The pool was drained
without appropriate authorizations under County of Sonoma ordinances
(P. Shannin, U.S. Army Corps of Engineers (Corps), pers. comm., 2002;
P. Stamp, Sonoma County Planning Department, pers. comm., 2002).
Roads and Highways
California tiger salamanders require a large amount of barrier-free
landscape for successful migration (Shaffer et al. 1993; Loredo et al.
1996). Roads and highways are permanent physical obstacles that can
block the animals from moving to new breeding habitat, or prevent them
from returning to their breeding ponds or estivation sites. Road
construction can reduce or completely eliminate the viability of a
breeding site, and in some cases, larger portions of a metapopulation.
All the pools at the known extant Sonoma County California tiger
salamander breeding sites are within 450 m (1,476 ft) of roads of
various sizes. Findlay and Houlahan (1996) found that roads within
2,000 m (1.2 mi) of wetlands adversely affected the number of amphibian
species. At this time, it is still possible for salamanders at breeding
sites associated with the Air Center to migrate to the FEMA/Broadmore
North Preserves. A proposed through-street and high-density housing
will eliminate this migration corridor, leading to fragmentation and
further isolation of remaining breeding sites. If this planned through-
street and accompanying high-density housing are completed, only three
breeding sites will remain where salamanders can access more than one
breeding pool without crossing roads.
Large numbers of California tiger salamanders at some locations in
the Central Valley, up to 15 or 20 per mile of road (J. Medeiros,
Sierra College, pers. comm., 1993), have been killed as they crossed
roads on breeding migrations (Hansen and Tremper 1993; S. Sweet, in
litt., 1993). Estimates of losses to automobile traffic range from 25
to 72 percent of the breeding population for several different
populations of the species (Twitty 1941; S. Sweet, in litt., 1993;
Launer and Fee 1996). Curbs and berms as low as 9 to 13 cm (3 to 5 in),
which allow salamanders to climb onto the road but can restrict or
prevent their movements off the roads, can turn the roads into sources
of high mortality (Launer and Fee 1996; S. Sweet, in litt., 1998).
Automobile traffic along Stony Point Road in western Santa Rosa has
probably quadrupled in the past 5 years (D. Cook, pers. comm., 2002).
This was once a moderately used rural road which is now a major route
for commuter traffic. Between November 21, 2001, and December 5, 2001,
26 California tiger salamanders were found killed by cars on this road
between Santa Rosa and Cotati. Fourteen of these dead California tiger
salamanders were found along Stoney Point Road near Meachum Road (D.
Cook, pers. comm., 2002). The Engel Preserve is adjacent and north of
Todd Road. A proposed road widening project along Todd Road would
likely increase traffic and result in an increased threat of roadkill
for salamanders migrating between the Engel Preserve and salamander
estivation habitat south of Todd Road.
Description of the Breeding Sites
(1) Hall Road Preserve: This 74-ha (183-ac) site is owned by CDFG.
It is the largest preserved area where the Sonoma County California
tiger salamander is currently known to occur. It contains two pools
with ponding levels adequate for successful breeding during drought
years. This preserve contains seven additional breeding pools that are
relatively shallow and do not pond water long enough for successful
breeding in years of moderate to low rainfall. Surveys conducted over
the past 2 years indicate this preserve does not function as a highly
productive breeding site (Cook and Northern 2001). The land surrounding
the preserve is privately owned, and the City of Santa Rosa has issued
permits for urban development. Urban development has occurred on
adjacent lands to the east and west, and agriculture to the north of
the preserve. Exotic predators of the salamander, such as Louisiana
crayfish (Procrambus clarkii), stickleback fish (Gasterosteus
aculeatus), and possibly bullfrogs (Rana catesbeiana) are present at
the Hall Road Preserve.
(2) FEMA/Broadmore North Preserves: This breeding site consists of
two properties, the FEMA Preserve and the Broadmore North Preserve. The
24-ha (59-ac) FEMA Preserve is owned by CDFG and contains one of the
most productive Sonoma County California tiger salamander breeding
sites. The 6.5-ha (16-ac) Broadmore North Preserve is a conservation
area that was set aside as mitigation by the Bellvue School District.
It is also managed by CDFG. The two breeding sites are contiguous and
encompass 30 ha (75 ac) containing three breeding pools. The FEMA
Preserve has two large, deep pools that remain ponded late in the
season. Salamanders probably breed there during most years. The one
breeding pool on Broadmore North is shallow and does not contribute
salamanders to the population in dry years (i.e., there is no
recruitment) (D. Cook, pers. comm., 2001). While there is no
hydrological connection between this site and the deeper pools
contained on the FEMA Preserve, the FEMA Preserve probably allows the
salamanders at the Broadmore North Preserve the opportunity to breed
during dry years. Urban development has occurred to the north and east
sides of the preserves. Although these breeding sites are protected,
urbanization imperils upland habitats on private land to the east and
west of them. A new road and housing development on lands adjacent to
the
[[Page 13510]]
preserves' western boundaries have been permitted by the City of Santa
Rosa and are now partially constructed. This new road and construction
has partially blocked the western migration route between breeding
pools at the Air Center and the pools at the FEMA and Broadmore North
preserves. Planned future phases of this project, also permitted by the
City of Santa Rosa, will totally block migration between the FEMA/
Broadmore North Preserves and the Air Center.
(3) Engel Preserve: This is a 16-ha (40-ac) privately owned
preserve that contains approximately 7 ha (18 ac) of wetlands. Three
pools appear to have ponding levels adequate for salamander breeding in
normal to dry rainfall years. Sonoma County California tiger
salamanders were not documented at this site prior to the 2001/2002
rainy season. Based on the small number of larvae found at this site,
however, it is likely that there are low numbers of salamanders
inhabiting this site. Todd Road runs along the southern boundary of
this site and automobile traffic poses a threat to salamanders
migrating between the Engel Preserve and estivation sites to the south.
(4) Northwest Air Center: This breeding site contains one breeding
pond and is located on private land. Much of the associated upland has
recently been developed. This site is bordered on the west and north by
roads subject to heavy traffic from housing developments that have been
constructed under the City of Santa Rosa's Southwest Area Development
Plan. Housing has eliminated migration routes to the east and south,
thus leaving this site as an isolated breeding site with less than 22
ha (55 ac) of remaining undeveloped upland area and pool with private
lands surrounding it to the south and east (M. Enright, pers. comm.,
2001).
(5) Southwest Air Center: This breeding site is located on private
land and contains one breeding pool. The City of Santa Rosa has issued
permits for a residential development that likely will result in the
elimination of salamanders at this location. Preparation of this site
for construction was initiated, but further development has been
delayed as a result of the emergency listing of this species. The
salamanders at this location also may utilize the breeding ponds at the
FEMA/Broadmore North preserves by an existing migration corridor to the
east. The destruction of this breeding site likely will further isolate
the animals inhabiting this location. Loss of this breeding site will
contribute to the overall isolation of the remaining breeding sites.
(6) North Air Center: There is one breeding pool on this privately
owned site. Recent residential and commercial developments that border
the breeding site on three sides severely restrict the potential for
migration. The City of Santa Rosa has approved residential and road
projects for this location that will adversely affect the salamanders.
This site is bordered by houses to the west, a road with high levels of
automobile traffic to the north, and a corporate park to the east.
There is a small tract of undeveloped private land to the south. No
protection exists for the uplands or breeding pool which is located
directly south of Sebastopol Road. The upland area is about 15 ha (37
ac). Portions of Sebastopol Road have been widened to four traffic
lanes, including the construction of storm drains and curbs. The curbs
likely funnel migrating salamanders into storm drains where they perish
after being washed into the sewer system. Residential and commercial
projects currently are under construction in this area. The City of
Santa Rosa has issued permits for the development of this site, and the
Corps has requested formal consultation from us for the fill of this
breeding site. Development plans will also result in the loss of
estivation habitat. Preparation of this site for construction was
initiated, but further development has been delayed as a result of the
emergency listing of this species.
(7) Wright Avenue: This breeding site is located on private land.
Approved development described in the City of Santa Rosa's Southwest
Area Development Plan will isolate this breeding site through increased
automobile traffic and residential development along Wright and Ludwig
Avenues. No construction is specifically proposed for this property,
but no protection exists to prevent the breeding site and associated
uplands from being developed. This site is on agricultural lands, and
access has not been allowed for several years. Thus, the condition, or
even the continued existence of this pool, cannot be confirmed.
(8) South Ludwig Avenue: This breeding site is located on private
land, and current threats to the salamanders include increased traffic
along Ludwig Avenue due to increasing residential development. The
breeding site and associated uplands are currently not protected from
potential development. This site is on agricultural lands, and access
has not been allowed for several years. Thus, the condition, or even
the continued existence of this pool cannot be confirmed.
Conclusion for Factor A
Except for the Hall Road Preserve, all of the known breeding sites
of the Sonoma County California tiger salamander are found on small
locations in areas being rapidly converted from low-intensity farming,
cattle grazing, and low-density housing, to high-density housing and
office buildings. Only three breeding sites (the Hall Road Preserve,
FEMA/Broadmore North Preserve, and Engel Preserve) have hydrologic
regimes adequate to provide recruitment for Sonoma County California
tiger salamanders in normal to dry years. Five of the breeding sites
are on private property. Two of the breeding sites on private lands are
on agricultural lands where access for salamander surveys has not been
allowed in recent years. Thus, it is unknown if these two breeding
sites still have Sonoma County California tiger salamanders, or if they
retain hydrological features required for successful salamander
breeding. Four of the breeding locations associated with the old
airfield in southwest Santa Rosa are slated for development, which will
disrupt the hydrology of the surrounding uplands by altering natural
runoff. If plans for the development of the area in the vicinity of
these four breeding sites are completed, there will be no migratory
corridors remaining between any of the currently extant breeding
locales.
Maintenance of tracts of habitat between breeding sites will likely
play a pivotal role in maintenance of the Sonoma County California
tiger salamander metapopulation dynamics. If breeding sites are
eliminated and the metapopulation becomes so fragmented that
individuals are unable to disperse between suitable patches of habitat,
the probability of natural recolonization will not offset the
probability of extinction. Some of the salamander breeding sites, such
as the FEMA Preserve/ Broadmore North Preserve and the pools associated
with the Air Center, are linked to each other by suitable habitat. If
movements through these linkages are disrupted or precluded (e.g., by
urban development), then the stability of the metapopulation (i.e., the
exchange of individuals between breeding sites) will be affected.
Isolation, whether by geographic distance or ecological factors, will
prevent the influx of new genetic material, and likely to result in
inbreeding and eventual extinction (Levin 2002). We believe that the
Sonoma County California tiger salamander is at risk from increasing
[[Page 13511]]
fragmentation and isolation caused by urban development.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
In the past, the larvae of non-native tiger salamanders could
legally be used as bait by fishermen in California. The extent of the
use of the Sonoma County California tiger salamander is unknown. The
California Code of Regulations (2002) now specifies that no salamander
may be used as bait and excludes the California tiger salamander from a
list of salamanders, newts, toads, and frogs that may legally be taken
and possessed under authority of a sportfishing license. The success of
these present regulations in avoiding or reducing recreational harvest
of the California tiger salamander is unknown.
Tiger salamanders are generally thought to make good pets by
amateur herpetologists (Porras 2002). The Sonoma County California
tiger salamander does not appear to be particularly popular among
amphibian and reptile collectors. However, Federal listing could raise
the value of the species within wildlife trade markets, and increase
the threat of unauthorized collections above current levels (K.
McCloud, Special Agent, Service, pers. comm., 2002). Even limited
interest in the species could pose a serious threat to the DPS.
C. Disease or Predation
Disease
Relatively little is known about the diseases of wild amphibians
(Alford and Richards 1999). The specific effects of disease on the
Sonoma County California tiger salamander are not known and the risks
to the animal have not been determined. However, it is known that mass
mortalities of amphibians from disease are not uncommon, and may be
either a natural phenomenon of the biology of species or induced by
anthropogenic agents (Corn 1994). In California, large numbers of dead
and dying California tiger salamanders were observed in a pond in the
Los Alamos Valley in Santa Barbara County, but the cause was not
determined (S. Sweet, pers. comm., 1998).
Worthylake and Hovingh (1989) described repeated die-offs of tiger
salamanders (A. tigrinum) at Desolation Lake in the Wasatch Mountains
of Utah. Affected salamanders had red, swollen hind legs and vents, and
widespread hemorrhage of the skin and internal organs. The researchers
determined that the die-offs were due to infection from the bacterium
Acinetobacter, or redleg disease. The number of Acinetobacter in the
lake increased with increasing nitrogen levels as the lake dried. The
nitrogen was believed to come from both atmospheric deposition and
waste from sheep grazing in the watershed (Worthylake and Hovingh
1989). Acinetobacter, which appears to affect amphibians whose immune
systems have been weakened by stress (Corn 1994) or another bacterial
infection, was also the suspected cause of larval tiger salamanders
deaths in Arizona (Collins et al. 1988, as cited in Corn 1994).
Acinetobacter is common in soil and animal feces.
Lefcort et al. (1997) found that tiger salamanders raised in
natural and artificial ponds contaminated with silt were susceptible to
infection by the water mold Saprolegnia parasitica at a location in
Georgia. This fungus first appeared on the feet, spread to the entire
leg, and then infected animals died. Die-offs of western toads (Bufo
boreas), Cascades frogs (Rana cascadae), and Pacific treefrogs also
have been associated with Saprolegnia infections (Kiesecker and
Blaustein 1997). Saprolegnia is widespread in natural waters and
commonly grows on dead organic material (Wise et al. 1995). Saprolegnia
ferax outbreaks have been identified as a cause of high amphibian
embryo mortalities in the Pacific Northwest (Kiesecker et al. 2001).
Viruses associated with die-offs of tiger and spotted salamanders
in Maine and North Dakota have been isolated (B. McLean, National
Wildlife Health Center, in litt., 1998). Also, Jancovich et al. (1997)
isolated a virus, believed to be an iridovirus, as the primary pathogen
responsible for a decimating epizootic event affecting the federally
endangered Sonoran tiger salamander (Ambystoma tigrinum stebbinsi) in
Arizona. Iridoviruses have recently been implicated as the cause of
amphibian mass deaths worldwide, with novel iridoviruses identified
from a number of regions.
Ranaviruses are often highly virulent and cause systemic infections
in amphibians. Epizootiology (science that deals with the character,
ecology, and causes of outbreaks of animal diseases) of ranaviral
disease in amphibians is poorly understood, but dissemination may be
partly due to the virus's ability to remain infectious under adverse
conditions and for prolonged periods. Likely modes of spread of
amphibian ranaviruses may include use of fishing gear, including boats,
and through artificial stocking of ponds for recreational fishing.
Also, water birds have the potential to mechanically transfer the virus
on their feathers, feet, or bills, or by regurgitation of ingested
infected material. Some outbreaks of ranaviral disease in tiger
salamanders have been associated with altered habitats and artificial
ponds. Due to their highly virulent nature, ranaviruses should be
considered a potential threat to amphibian populations, especially
those isolated from previous disease outbreaks (and thus lacking
specific immunity) and species with low fecundity (Daszak et al. 1999).
Kiesecker et al. (2001) reported that pathogen outbreaks in
amphibian populations in the western U.S. may be linked to climate-
induced changes in UV-B light exposure. Their findings indicate that
climate-induced reductions in water depth at oviposition (laying of
eggs) sites have caused high mortality of embryos by increasing their
exposure to UV-B radiation and, consequently, their vulnerability to
infection. Furthermore, they speculate that climate changes since the
mid-1970s related to El Ni[ntilde]o/Southern Oscillation cycles and
elevated sea-surface temperatures could be the precursor for pathogen-
mediated amphibian declines in many regions.
Pathogen outbreaks have not been documented in Sonoma County
California tiger salamanders. Nevertheless, disease must be considered
a potential future population threat because of the relatively small,
fragmented remaining Sonoma County California tiger salamander breeding
sites, the many stresses on these sites due to habitat losses and
alterations, and the many other potential disease-enhancing
anthropogenic changes which have occurred both inside and outside of
the range of this DPS. An amphibian pathogen could eliminate one or
more breeding sites of this animal.
Predation
Predation and competition by introduced or non-native species
potentially affect all of the known Sonoma County California tiger
salamander breeding sites. Bullfrogs prey on California tiger
salamanders (P. Anderson 1968; Lawler et al. 1999). Morey and Guinn
(1992) documented a shift in amphibian community composition at a
vernal pool complex, with California tiger salamanders becoming
proportionally less abundant as bullfrogs increased in number. Lawler
et al. (1999) found that less than 5 percent of California red-legged
frog (Rana aurora draytonii) tadpoles survived to metamorphosis when
raised with bullfrog tadpoles. Moyle (1973) attributed disappearance of
both
[[Page 13512]]
California red-legged frogs and foothill yellow-legged frogs (Rana
mucosa) within the San Joaquin Valley of California to habitat
alteration coupled with predation and competition from bullfrogs.
Although bullfrogs are unable to establish permanent breeding
populations in unaltered vernal pools and seasonal ponds, dispersing
immature bullfrogs take up residence in such water bodies during winter
and spring where they prey on native amphibians, including larval
salamanders (Morey and Guinn 1992; Seymour and Westphal 1994).
Because bullfrogs are known to travel at least 2.6 km (1.6 mi) from
one pond to another (Bury and Whelan 1984), they have the potential to
naturally colonize new areas where they do not currently exist,
including ponds where Sonoma County California tiger salamanders occur.
In one study of the eastern San Joaquin Valley, 22 of 23 (96 percent)
ponds with California tiger salamanders were within the bullfrogs'
potential dispersal range (Seymour and Westphal 1994). In addition,
because bullfrogs are still sought within California for sport and
food, and may be taken without limit under a fishing license, the
threat of transport for intentional establishment in new locations
where California tiger salamanders exist or could exist is significant.
One of the pools at the Hall Road breeding site, and two of the
pools contained at the FEMA/Broadmore North preserves, are located
within 46 m (150 ft) of ditches or creek channels known to contain
bullfrogs or crayfish. Bullfrogs likely occur in Roseland Creek, which
is near the FEMA/Broadmore North preserve and breeding sites associated
with the Air Center (D. Cook, pers. comm., 2002). Bullfrogs are likely
present in ditches that cross the Hall Road Preserve (D. Cook, pers.
comm., 2002). The direct and indirect evidence thus indicates that non-
native bullfrogs represent a continuing significant threat to the
persistence of the Sonoma County California tiger salamander.
Western mosquitofish (Gambusia affinis) are native to central North
America (watersheds tributary to the Gulf of Mexico) and have been
introduced throughout the world for mosquito control, including in
California beginning in 1922. Western mosquitofish now occur throughout
California wherever the water does not get too cold for extended
periods, and they are still widely planted throughout the State (Boyce,
UCD, in litt., 1994) by about 50 local mosquito abatement districts.
Salamanders may be especially vulnerable to western mosquitofish
predation due to their fluttering external gills, which may attract
these visual predators (Graf and Allen-Diaz 1993). Loredo-Prendeville
et al. (1994) found no California tiger salamanders inhabiting ponds
containing western mosquitofish. Western mosquitofish prey on other
amphibian species, such as the California newt (Taricha torosa)
(Gamradt and Kats 1996) and Pacific treefrog (Goodsell and Kats 1999)
tadpoles in both field and laboratory experiments, even given the
optional prey of mosquito larvae (Goodsell and Kats 1999; L. Kats,
Pepperdine University, pers. comm., 1999). Mosquitofish have also been
observed ingesting and then spitting out California newt larvae,
causing severe damage to the newts in the process (Graf and Allen-Diaz
1993). Given the effects of western mosquito fish on other amphibian
species, they are likely to have similar effects on California tiger
salamanders. If they have the same effects, the use of mosquito fish in
California tiger salamander habitat threatens the persistence of the
species, especially in the isolated Sonoma County California tiger
salamander population.
Other non-native fish have either been directly implicated in
predation of California tiger salamanders or appear to have the
potential for such. For example, introductions of sunfish species
(e.g., largemouth bass (Micropterus salmoides) and bluegill (Lepomis
macrochirus)), catfish (Ictalurus spp.), and fathead minnows
(Pimephales promelas) are believed to have eliminated California tiger
salamanders from several breeding sites in Santa Barbara County
(Service 2000). Non-native sunfish species, catfish, and bullheads
(Ameiurus spp.) have been, and still are, widely planted in ponds in
California to provide for sportfishing. By 1984, the California fish
fauna included about 50 such transplanted and exotic species, mostly
from eastern North America origin (Hayes and Jennings 1986). More
recently, Moyle (2002) estimated that, on average, California is losing
about one native species or subspecies of fish every 5 to 6 years, and
gaining an average of one alien species about every 2 years.
Non-native fish introductions may be responsible for the declines
of frog species in western North America (Hayes and Jennings 1986).
Such introduced fish may be a problem for California raids because of
their specialization for preying on aquatic life (including eggs and
larvae), and because the affected amphibians may have evolved under
conditions of limited fish predation, which now increases the impacts
of such introductions (Hayes and Jennings 1986). We believe the same
threat applies to the California tiger salamander. Thus, potential
introduction of such non-native fish species in Sonoma County
California tiger salamander breeding habitat should be considered a
threat to the persistence of this DPS.
The degree to which predation from native fish have affected the
Sonoma County California tiger salamanders is unknown. For example,
sticklebacks (Gasterosteus spp.), which have been present in California
for at least 16 million years, were believed to be the factor
preventing the Sonoma County California tiger salamander from
establishing at a site in Sonoma County (Cook and Northen 2001). One
pool at the Hall Road Preserve appears to have all of the biological
components for successful California tiger salamander breeding, but has
a small connector to a drainage ditch containing stickleback. Sonoma
County California tiger salamanders have never been found at this site,
and it is suspected that predation of their eggs and larvae by this
fish is the limiting factor (D. Cook, pers. comm., 2002).
Non-native and native crayfish (Pacifastacus, Orconectes, and
Procambarus spp.) apparently prey on California tiger salamanders
(Shaffer et al. 1993) and may have eliminated some populations
(Jennings and Hayes 1994). Crayfish prey on California newt eggs and
larvae, despite toxins produced by these amphibians, and they may be a
significant factor in the loss of newts from several streams in
southern California (Gamradt and Kats 1996). These crayfish have been
found at both the FEMA/Broadmore North and Hall Road Preserves. At the
FEMA property, crayfish were found in the pool (D. Cook, pers. comm.,
2002). The crayfish likely came from the adjacent Roseland Creek
Channel. Louisiana crayfish have been found in the ditches that cross
the Hall Road Preserve, but not at any of the pools known to support
Sonoma County California tiger salamander populations (D. Cook, pers.
comm., 2002). The presence of both stickleback and crayfish, along with
the suspected presence of bullfrogs, could negatively affect Sonoma
County California tiger salamanders within the Hall Road Preserve.
California tiger salamanders are also likely preyed on by many
native species of fish and wildlife. In healthy salamander populations,
such predation is probably not a significant threat. But when combined
with other impacts,
[[Page 13513]]
such as predation by non-native species, contaminants, migration
barriers, or habitat alteration, it may cause a significant decrease in
population viability. Native predators include herons and egrets,
western pond turtles (Clemmys marmorata), various garter snakes
(Thamnophis spp.), larger California tiger salamanders, larger
spadefoot toads (Scaphiopus hammondii), and California red-legged frogs
(M. Peters, Service, in litt., 1993; Hansen and Tremper 1993). In
Arizona, larval tiger salamanders are preyed upon by adult predaceous
diving beetles (Dytiscus dauricus) (Holomuzki 1986), and turkey
vultures (Carthartes aura) have been observed feeding on larval or
adult tiger salamanders (Duncan 1999).
D. The Inadequacy of Existing Regulatory Mechanisms
The primary cause of the decline of the Sonoma County California
tiger salamander is the loss, degradation, and fragmentation of habitat
due to human activities. Federal, State, and local laws have been
insufficient to prevent past and ongoing losses of the limited habitat
of the Sonoma County California tiger salamander.
Federal
Clean Water Act. Under section 404 of the Clean Water Act (CWA) (33
U.S.C. 1344 et seq.), the U.S. Army Corps of Engineers (Corps)
regulates the discharge of fill material into waters of the United
States, including wetlands. Section 404 regulations require applicants
to obtain a permit for projects that involve the discharge of fill
material into waters of the United States, including wetlands. However,
normal farming activities are exempt under the CWA and do not require a
permit (53 FR 20764; Robert Wayland III, Environmental Protection
Agency (EPA), in litt., 1996). Projects that are subject to regulation
may qualify for authorization to place fill material into headwaters
and isolated waters, including wetlands, under several nationwide
permits. The use of nationwide permits by an applicant or project
proponent is normally authorized with minimal environmental review by
the Corps. No activity that is likely to jeopardize the continued
existence of a threatened or endangered species, or that is likely to
destroy or adversely modify designated critical habitat of such
species, is authorized under any nationwide permit. An individual
permit may be required by the Corps if a project otherwise qualifying
under a nationwide permit would have greater than minimal adverse
environmental impacts.
Recent court cases may further limit the Corps' ability to utilize
the CWA to regulate the fill or discharge of fill or dredged material
into the aquatic environment within the current range of the Sonoma
County California tiger salamander (Solid Waste Agency of Northern Cook
County v. U.S. Army Corps of Engineers, 531 U.S. 159 (2001) (SWANCC)).
The effect of SWANCC on Federal regulation of activities in wetlands in
the area of the Sonoma County California tiger salamander has recently
become clear by the Corps' failure to assert its jurisdiction over fill
of several wetlands within the range of the Sonoma County California
tiger salamander. In a letter from the Corps dated March 8, 2002,
concerning the fill of 0.18 ha (0.45 ac) of seasonal wetlands southwest
of the intersection of Piner and Marlow Roads (Corp File Number
19736N), the Corps referenced the SWANCC decision and reiterated that
the subject wetlands were not ``waters of the United States'' because
they were: (1) Not navigable waters; (2) not interstate waters; (3) not
part of a tributary system to 1 or 2; (4) not wetlands adjacent to any
of the foregoing; and (5) not an impoundment of any of the above. The
letter further stated that the interstate commerce nexus to these
particular waters is insufficient to establish CWA jurisdiction and,
therefore, not subject to regulation by the Corps under section 404 of
the CWA. The Corps also cited the SWANCC decision as their reasoning
for not taking jurisdiction over fill of Sonoma County California tiger
salamander breeding pools at the recently constructed South Sonoma
Business Park.
When on- or off-site mitigation is required by the Corps as a
condition of a section 404 permit to fill certain wetlands, there is
often low probability that affected Sonoma County California tiger
salamander habitat values, if any, would actually be compensated and
replaced by the ensuing mitigation action(s). A 1994 Service study of
selected wetlands re-creation projects in California authorized through
the section 404 program found deficiencies in both compliance and
performance of the re-created wetlands (Santa Rosa Plain Vernal Pool
Ecosystem Preservation Plan 1995). There was evidence that, of all the
proposed mitigation, half of the sites were meeting less than 75
percent of the mitigation conditions and our goal for ``in-kind''
replacement was not being met (DeWeese 1994). Other recent studies have
produced similar results. In addition, most wetland re-creation efforts
in California to date have been directed at the wetlands themselves and
have not adequately addressed the upland and other related needs of
California tiger salamanders.
Semlitsch (1998) examined published literature for six species of
pond-breeding ambystomatid salamanders from five States and concluded
that a buffer zone encompassing 95 percent of a given population would
need to extend 263 m (534 ft) from a wetland's edge into surrounding
terrestrial habitat in order to give adequate protection. More
recently, Trenham (2001), although cautioning that essential
terrestrial habitats and buffer requirements are still relatively
poorly understood, concluded that plans to maintain local populations
of California tiger salamanders should include pond(s) surrounded by
buffers at least 173 m (567 ft) wide of terrestrial habitat occupied by
burrowing mammals. Management plans that focus only on preserving ponds
or wetlands--without consideration for associated terrestrial habitat--
are likely to fail to maintain viable amphibian populations (Marsh and
Trenham 2001). However, even with inclusion of terrestrial habitat
buffers, recent studies have demonstrated that restored wetlands are
often still only partially successful in recolonization by the full
amphibian assemblages being targeted for restoration (Lehtinen and
Galatowitsch 2001; Pechmann et al. 2001). Successful compensatory
mitigation for losses of California tiger salamander pool and pond
habitat due to filling would also require the connectivity of the
restoration site to other pools and ponds (Gibbs 1998; Lehtinen et al.
1999; Trenham et al. 2001; Marsh and Trenham 2001). Pond isolation may
be an important consideration in disturbed environments where inter-
pond dispersal is impeded by barriers such as roads and urban
development (Marsh and Trenham 2001). The California tiger salamander
may also require large preserves to maintain viable breeding
populations and to allow recolonizations from natural and anthropogenic
local extirpations (P. Northen, in litt., 2001).
Three federally endangered plants, Sonoma sunshine (Blennosperma
bakeri), Sebastopol meadowfoam (Limnanthes vinculans), and Burke's
goldfields (Lasthenia burkei) occur on the Santa Rosa Plain of Sonoma
County in the vicinity of the Sonoma County California tiger
salamander. However, little overlap occurs between the viable breeding
sites of this species and these federally listed vernal pool species.
Any Corps consultation requirement for fill
[[Page 13514]]
of pools on the Santa Rosa Plain would be triggered by the listed
plants. Since the salamander and the federally listed plants do not
substantially overlap, salamander breeding pools are unlikely to be
protected by presence of the plants or their habitat. Furthermore, even
if breeding pools of this animal are avoided due to the presence of a
federally listed plant species, this protection may only extend to the
pool itself with a small upland buffer. Since Sonoma County California
tiger salamanders spend up to 80 percent of their life in small mammal
burrows in upland habitats surrounding breeding pools, the protection
of the pool itself, with concurrent loss of uplands surrounding the
pool, would still result in the loss of local Sonoma County California
tiger salamander breeding sites.
We conclude that regulation of wetlands filling by the Corps under
section 404 of the CWA is inadequate to protect the Sonoma County
California tiger salamander from further decline. Section 404
implementation fails to prevent losses of numerous small wetlands in
California that may support California tiger salamander breeding.
Section 404 does not regulate the continuing losses of California tiger
salamander terrestrial habitat (except to the extent certain
agricultural activities may be regulated). When authorized fills under
section 404 do result in compensatory mitigation for wetlands losses,
it is unlikely that California tiger salamander habitat losses at
specific fill sites can, and will be, fully and successfully mitigated.
State
Since 1994, the CDFG recognizes the California tiger salamander as
a ``species of special concern'' by the CDFG. More recently, the
California tiger salamander has been placed on the State's list of
protected amphibians, which means that it cannot be taken without a
special permit issued for scientific collecting or research. Also, as
stated earlier, the California Code of Regulations (2002) specifies
California tiger salamanders can no longer be taken, possessed, or used
for fishing bait. However, any more stringent protection of California
tiger salamanders or their habitat, as would be provided under a CESA
listing or designation as a Fully Protected species by CDFG, is
lacking.
CDFG recognizes the importance of California tiger salamander
conservation at the local population level, and routinely considers and
recommends actions to mitigate potential adverse effects to the species