Federal Register, Volume 59 Issue 24 (Friday, February 4, 1994)

[Federal Register Volume 59, Number 24 (Friday, February 4, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-2548]

[[Page Unknown]]

[Federal Register: February 4, 1994]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AC32

Endangered and Threatened Wildlife and Plants; Proposed
Endangered Status for the Callippe Silverspot Butterfly, Behren's
Silverspot Butterfly, and the Alameda Whipsnake From Northern and
Central California

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The Service proposes to determine the callippe silverspot
butterfly (Speyeria callippe callippe), Behren's silverspot butterfly
(Speyeria zerene behrensii), and the Alameda whipsnake (Masticophis
lateralis euryxanthus) as endangered pursuant to the Endangered Species
Act of 1973, as amended (Act). The three species are found in northern
and central California.
These animals and the foodplants of the larval butterflies occur on
private, county, and State land, and are imperiled by one or more of
the following: overcollecting, commercial and residential development,
competition from alien plants, inappropriate levels of livestock
grazing, off-road vehicle use, trampling by hikers and livestock, and
perhaps stochastic (i.e., random) extinction by virtue of the small,
isolated nature of the remaining populations. This proposal, if made
final, would implement protection provided by the Act for these
animals. Critical habitat is not being proposed.

DATES: Comments from all interested parties must be received by April
5, 1994. Public hearing requests must be received by March 21, 1994.

ADDRESSES: Comments and materials concerning this proposal should be
sent to the Field Supervisor, Sacramento Field Office, U.S. Fish and
Wildlife Service, 2800 Cottage Way, room E-1823, Sacramento, California
95825. Comments and materials received will be available for
inspection, by appointment, during normal business hours at the above
address.

FOR FURTHER INFORMATION CONTACT: Mr. Chris Nagano at the above address
or by telephone (916/978-4866).

SUPPLEMENTARY INFORMATION:

Background

The callippe silverspot butterfly (Speyeria callippe callippe) is a
member of the Nymphalidae family. The animal was described by J.A.
Boisduval (1852) from specimens collected during the month of June by
Pierre Lorquin in San Francisco, California (dos Passos and Grey 1947).
Arnold (1983, 1985) conducted taxonomic studies on the subspecies of
Speyeria callippe using wing characters. His investigation concluded
that the species consisted of 3 subspecies rather than the widely
recognized and accepted 16 subspecies. Based on his study, the range of
Speyeria callippe callippe would extend from Oregon to southern
California and east into the Great Basin (Arnold 1985). A comprehensive
analysis of this species found that the original classification remains
more appropriate and that subspecies callippe is restricted to the
northern San Francisco Bay region (Hammond 1986, Murphy undated).
Hammond determined that the analysis by Arnold used invalid
morphological characteristics. The Service recognizes the conclusions
of Hammond (1986) and the distribution of the callippe silverspot
butterfly as described by Sterling Mattoon (Sterling Mattoon, amateur
lepidopterist, in litt., 1991).
The callippe silverspot butterfly is a medium-sized butterfly with
a wingspan of approximately 55 millimeters (2.17 inches). The upper
wings are brown with extensive black spots and lines, and the basal
areas are extremely melanic (dark-colored). The undersides are brown,
orange-brown, and tan with black lines and distinctive black and bright
silver spots. The basal areas of the wings and body are densely
pubescent (hairy). The discal area on the upper wings of the callippe
silverspot butterfly is darker and more extensively yellow on the
hindwings than the related Lilian's silverspot butterfly (Speyeria
callippe liliana). The callippe silverspot butterfly is larger and has
a darker ground color with more melanic areas on the basal areas of the
wings than Comstock's silverspot butterfly (Speyeria callippe
comstocki).
The callippe silverspot butterfly is found in native grassland and
adjacent habitats (Steiner 1990; Mattoon, in litt., 1991; Thomas Reid
Associates 1982). The females lay their eggs on the dry remains of the
larval foodplant, Johnny jump-up (Viola pedunculata), or on the
surrounding debris (Arnold 1981, Thomas Reid Associates 1982). Upon
hatching after about a week, the larvae eat their egg shells. The
caterpillars wander a short distance and spin a silk pad upon which
they spend the summer and winter. The larvae are dark-colored with many
branching sharp spines on the back. Upon termination of diapause in the
spring, the caterpillars immediately seek out the foodplant. In May,
after having gone through five instars (i.e., skin sheddings), the
larvae form pupa within a chamber of leaves that they have drawn
together with silk. The adults emerge in about 2 weeks and live for
approximately 3 weeks. Depending upon environmental conditions, the
flight period of this single-brooded butterfly ranges from mid-May to
late July. The adults exhibit hilltopping behavior, a phenomenon in
which males and females seek a topographic summit to mate (Shields
1967).
The callippe silverspot butterfly was known historically to occur
in seven populations in the San Francisco Bay region. This animal does
not occur north of the Golden Gate or Carquinez Straits (Mattoon, in
litt., 1991; Paul Opler, U.S. Fish and Wildlife Service, pers. comm.,
1992). The historic range of the callippe silverspot butterfly includes
the inner coast range on the eastern shore of San Francisco Bay from
northwestern Contra Costa County south to the Castro Valley area in
Alameda County. On the west side of the Bay, it ranged from San
Francisco south to the vicinity of La Honda in San Mateo County. Five
colonies, including the one located at Twin Peaks in San Francisco,
were extirpated. The remaining colonies exist on mostly privately owned
land, but also on city, county, and State owned land. Currently, extant
colonies are known only from San Bruno Mountain in San Mateo County and
a city park (Mattoon, in litt., 1991).
Behren's silverspot butterfly (Speyeria zerene behrensii) is a
member of the Nymphalidae family. William H. Edwards described this
taxon in 1869 based on an adult male collected by an unknown
lepidopterist in Mendocino, California (dos Passos and Grey 1947,
Edwards 1869). It is a medium-sized butterfly with a wingspan of
approximately 55 millimeters (2.17 inches). The upper surfaces are
golden brown with numerous black spots and lines. The undersides are
brown, orange-brown, and tan with black lines and distinctive silver
and black spots. The basal areas of the wings and body are densely
pubescent.
Behren's silverspot butterfly is similar in appearance to two other
subspecies of Speyeria zerene (Hammond 1980, Howe 1975, McCorkle and
Hammond 1988). The threatened Oregon silverspot butterfly (Speyeria
zerene hippolyta) has lighter basal suffusion on the upper sides of the
wings than Behren's silverspot butterfly. Another related taxon, the
endangered Myrtle's silverspot butterfly (Speyeria zerene myrtleae), is
larger in size and also lighter in color than Speyeria zerene
behrensii.
Behren's silverspot butterfly inhabits coastal terrace prairie
habitat. The life history of Behren's silverspot butterfly is similar
to the callippe silverspot butterfly. The females lay their eggs in the
debris and dried stems of the larval foodplant, violet (Viola adunca)
(McCorkle 1980, McCorkle and Hammond 1988). Upon hatching, the
caterpillars wander a short distance and spin a silk pad upon which
they pass the fall and winter. The larvae are dark-colored with many
branching sharp spines on the back. The caterpillars immediately seek
out the foodplant upon termination of diapause in the spring. Each
larva then forms a pupa within a chamber of leaves that they have drawn
together with silk. The adults emerge in about 2 weeks and live for
approximately 3 weeks. Depending upon environmental conditions, the
flight period of this single brooded butterfly ranges from July to
August. Adult males patrol open areas in search of newly emerged
females.
The historic range of Behren's silverspot butterfly extends from
the mouth of the Russian River in Sonoma County northward along the
immediate coast to southern Mendocino County in the vicinity of Point
Arena (Mattoon, in litt., 1989). The six historic populations were
known to occur in coastal terrace prairie and adjacent habitats. The
single extant population, which was recently discovered, occurs on
privately owned land near Point Arena in Mendocino County.
The Alameda whipsnake (Masticophis lateralis euryxanthus) is a
member of the Colubridae family (Morey and Bioassay 1988). It was
described by William Reimer (1954) from a specimen collected in
Berkeley Hills, Alameda County, California. The common name ``Alameda
whipsnake'' is utilized in this proposed rule instead of ``Alameda
striped racer'' that was used in the November 21, 1991, Animal Notice
of Review (56 FR 58804). ``Whipsnake'' is a widely recognized common
name for other members of the genus Masticophis (Stebbins 1985). The
Alameda whipsnake is a slender, fast moving diurnal snake with a narrow
neck and a relatively broad head with large eyes. The dorsal surface is
colored sooty black or dark brown with a distinct yellow-orange stripe
down each side. The anterior portions of the ventral surface are
orange-rufous colored, the midsection is cream colored, and the
posterior and tail are pinkish. The adults reach a length of 91 to 122
centimeters (3 to 4 feet). This subspecies is distinguished from the
more common California whipsnake (M. l. lateralis) by its comparatively
wide orange stripes, which run laterally down each side.
The Alameda whipsnake inhabits the inner coast range in western and
central Contra Costa and Alameda Counties (McGinnis 1992). One of the
two major populations extends from approximately El Sorbante south to
about Hayward. The second is found from Clayton/Mount Diablo southeast
to the Vasco Road area. It occurs mostly on privately owned land, but
also occurs on State and county land.
The Alameda whipsnake usually is found in northern coastal scrub or
chaparral, but it also may occur in adjacent habitats. This extremely
fast-moving, lizard-eating specialist holds its head high off the
ground in a cobra-like manner to peer over grass or rocks at potential
prey. The Alameda whipsnake has been found to exhibit territorial
behavior, possessing home ranges varying in size from 2 to 8.7 hectares
(5.0 to 21.5 acres). Some animals have been recorded to have moved over
1 mile while traversing their areas (McGinnis 1992). The life history
of the Alameda whipsnake is not well understood (Goldberg 1975,
Hammerson 1978).
A proposed rule to list the callippe silverspot butterfly as
endangered with critical habitat was published on July 3, 1978 (43 FR
28938). The critical habitat portion of that proposal was withdrawn by
the Service on March 6, 1979 (44 FR 12382), because of procedural and
other substantive changes in the Endangered Species Act by the 1978
amendments. The Service again published a proposed rule to designate
critical habitat for the callippe silverspot butterfly on March 28,
1980 (45 FR 20503). The proposed rule to list the callippe silverspot
butterfly was withdrawn on September 30, 1980 (45 FR 64607), because
the 1978 Endangered Species Act amendments required that the final rule
for the species be completed within 2 years after the date of
publication proposing to list it as endangered or threatened.
The callippe silverspot butterfly was listed as a category 2
candidate species in the May 22, 1984 (49 FR 21664), and January 6,
1989 (54 FR 554), Animal Notices of Review. This category includes
species that may be appropriate to list as endangered or threatened,
but for which conclusive data on their biological vulnerability is not
currently available to support proposed rules. The species was listed
as a category 1 candidate species in the November 21, 1991 (56 FR
58804), Animal Notice of Review because of increased threats from
overcollecting (see Factor B in the ``Summary of Factors Affecting the
Species'' section). This category includes taxa for which the Service
has on file enough substantial information on biological vulnerability
and threats to propose listing them as endangered or threatened.
Ms. Dee Warenycia petitioned the Service to list the callippe
silverspot butterfly as an endangered species in a letter dated January
14, 1991, which was received on January 22, 1991. The Service completed
a status review and determined that enough information exists to
propose the species for listing. This proposal constitutes the final
finding for the petitioned action.
On March 20, 1975, Behren's silverspot butterfly was listed as 1 of
42 insects whose status was being reviewed for listing as either
endangered or threatened by the Service (40 FR 12691). This insect was
listed as a category 2 species in the May 22, 1984 (49 FR 21664), and
January 6, 1989 (54 FR 554), Animal Notices of Review. Dr. Dennis
Murphy of Stanford University petitioned the Service to list Behren's
silverspot butterfly as an endangered species in a letter dated June
28, 1989, which was received on June 29, 1989. The Service determined
that the petition contained substantial information indicating that the
requested action may be warranted and published notice of the 90-day
finding on November 1, 1990 (55 FR 46080). The Service did not receive
any new information in response to the November 1, 1990, notice.
However, the species was listed as a category 1 species in the November
21, 1991 (56 FR 58804), Animal Notice of Review on the basis of
significant increases in habitat loss and threats occurring throughout
its range. This proposal constitutes the final finding for the
petitioned action.
The Alameda whipsnake (as the Alameda striped racer) was listed as
a category 2 candidate species in the September 18, 1985 (50 FR 37958),
Vertebrate Wildlife Notice of Review. In the January 6, 1989 (54 FR
554), Animal Notice of Review, the Service again included the Alameda
whipsnake as a category 2 candidate species and solicited additional
information on its status. The November 21, 1991 (56 FR 58804), Animal
Notice of Review included the Alameda whipsnake as a category 1
candidate species on the basis of significant increases in habitat loss
and threats occurring throughout its range.
This proposal to list the callippe silverspot butterfly, Behren's
silverspot butterfly, and Alameda whipsnake is based on the best
available scientific and commercial information, various scientific
papers and unpublished reports available to the Service, and
information gathered from various scientists specializing in these
taxa, especially Mr. Sterling Mattoon and Mr. John Steiner.

Summary of Factors Affecting the Species

Section 4 of the Endangered Species Act (16 U.S.C. 1531 et seq.)
and regulations (50 CFR part 424) promulgated to implement the listing
provisions of the Act set forth the procedures for adding species to
the Federal Lists. Species may be determined 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 callippe silverspot
butterfly (Speyeria callippe callippe), Behren's silverspot butterfly
(Speyeria zerene behrensii), and Alameda whipsnake (Masticophis
lateralis euryxanthus) are as follows:
A. The present or threatened destruction, modification, or
curtailment of their habitat or range. The primary cause of the
declines of the callippe silverspot butterfly, Behren's silverspot
butterfly, and Alameda whipsnake is the loss of habitat from human
activities. These species are imperiled by the current and potential
future destruction and alteration of their habitats due to off-road
vehicle use, trampling by hikers and equestrians, unsuitable levels of
livestock grazing, and invasive exotic vegetation. The Alameda
whipsnake and Behren's silverspot butterfly also are imperiled by
residential and commercial development. Off-road vehicles and human or
horse trampling pose threats to the colonies of the two butterfly
species as these activities could crush the foodplants of the larvae or
the adult nectar sources.
The callippe silverspot butterfly was once more widespread in the
San Francisco Bay Area. At least five populations of this species have
been eliminated by urban development and other causes. The species
currently is known only from two sites in San Mateo and Alameda
Counties. One of the known extant populations of the callippe
silverspot butterfly is located in a city park. This colony is small
and may be imperiled by human-induced and natural causes (Mattoon, in
litt., 1991). The other known extant population of the callippe
silverspot butterfly is found on San Bruno Mountain in San Mateo County
(Mattoon, in litt., 1991; Thomas Reid Associates 1982). Although the
majority of the natural areas on San Bruno Mountain have been preserved
and will remain undeveloped in perpetuity, collection of specimens by
amateur lepidopterists poses a threat, as discussed under Factor B.
Behren's silverspot butterfly has been extirpated from a
significant portion of its former range, which extended from the mouth
of the Russian River in Sonoma County north to southern Mendocino
County. One of the six known historic colonies was eliminated by a
housing development (Mattoon, in litt., 1989). No specimens have been
observed at the other historic colonies since 1987. Currently, this
animal is known only from a recently discovered locality northwest of
the town of Point Arena in Mendocino County (Sally DeBecker, Pacific
Gas and Electric, pers. comm., 1990). The site is subject to grazing by
livestock. Although no plans have been proposed for the site, urban
development is occurring in the area.
The central and western portions of Alameda and Contra Costa
Counties are highly urbanized. Housing, commercial, and road
construction have greatly reduced the amount of suitable habitat
available for the Alameda whipsnake. McGinnis (1992) listed 60
localities for this species; 25 of them are considered to represent
extant populations. A proposed reservoir northeast of Lake Chabot in
Alameda County would result in the elimination of suitable habitat at
the site (McGinnis 1992). Flooding at the proposed Los Vaqueros
Reservoir in eastern Contra Costa County would not impact the reptile;
however, proposed quarrying operations for the production of material
for the dam and the inducement of development would result in habitat
destruction (McGinnis 1990, 1992). Numerous housing developments
currently threaten other populations. Within the City of Oakland, 6
residential projects have been built and 10 more are proposed in
Alameda whipsnake habitat (Charles Bryant, Oakland Planning Department,
in litt., 1992). A 1,600-acre site that contains suitable habitat for
the Alameda whipsnake in the City of Clayton is under review to
determine potential commercial uses (Randall Hatch, Clayton Planning
Department, in litt., 1991). McGinnis (1992) documented nine other
colonies scattered throughout the range of the snake that are likely to
be adversely impacted by several planned residential developments.
B. Overutilization for commercial, recreational, scientific or
educational purposes. Both the callippe silverspot butterfly and
Behren's silverspot butterfly are highly prized by insect collectors.
Although there are no studies of the impact of the removal of
individuals on natural populations of either of the butterfly species,
studies of another endangered nymphalid butterfly (Gall 1984a, 1984b)
and a lycaenid butterfly (Duffey 1968) indicate it is likely that the
callippe and Behren's silverspot butterflies could be adversely
affected due to their isolated, possibly small populations. The Service
is aware of preserved specimens of the callippe silverspot butterfly
that have been recently collected on San Bruno Mountain. Some of these
specimens are traded for other butterfly taxa or held by the collectors
in anticipation of their greater value if the species is listed. The
Service also is aware of reports that Behren's silverspot butterfly is
actively sought after by amateur lepidopterists.
There is an extensive commercial trade for the two butterfly
species proposed herein for listing, as well as other imperiled or rare
butterflies (Chris Nagano and John Mendoza, U.S. Fish and Wildlife
Service, pers. obs., 1992). Collecting from small colonies or repeated
handling and marking (particularly of females and in years of low
abundance) could seriously damage the populations through loss of
individuals and genetic variability (Gall 1984b, Murphy 1988, Singer
and Wedlake 1981). Collection of females dispersing from a colony also
can reduce the probability that new colonies will be established.
Collectors pose a threat because they may deplete butterfly colonies
below the thresholds of survival or recovery (Collins and Morris 1985).
The Alameda whipsnake does not appear to be particularly popular
among reptile collectors; however, Federal listing could raise the
value of the animals within reptilian trade markets and increase the
threat of unauthorized collection above current levels (Ken McCloud,
U.S. Fish and Wildlife Service, pers. comm., 1992). Even limited
interest in the species among reptile collectors could pose a serious
threat to populations that contain few individuals.
C. Disease or predation. There are no indications that disease or
predation pose a significant threat to the callippe silverspot
butterfly or Behren's silverspot butterfly. The real or potential
occurrence of disease in the Alameda whipsnake is unknown.
A number of native mammals and birds are known or likely to be
predators of the Alameda whipsnake, including kingsnakes (Lampropeltis
sp.), raccoons (Procyon lotor), skunks (Mephitis mephitis), opossums
(Didelphis marsupialis), foxes (Vulpes sp.), and hawks (Buteo sp.). The
introduction of the red fox (Vulpes vulpes), a species not native to
this region of the State, in the 19th century poses an additional
threat to the Alameda whipsnake. The snakes seem to protect themselves
both physically and behaviorally from this predator, perhaps due to
their adaptions to native predators, and the snake populations seem to
withstand predation from these animals. However, in situations where
Alameda whipsnake habitat has become fragmented, isolated, and
otherwise degraded by human activities, increased predatory pressure
may become excessive, especially where alien species, such as rats
(Rattus sp.), and feral and domestic cats and dogs are introduced.
These additional threats become particularly acute where urban
development is immediately adjacent to Alameda whipsnake habitat.
Although the actual impact of predation under such situations has not
been studied, the likelihood for serious impact exists.
D. The inadequacy of existing regulatory mechanisms. The callippe
silverspot butterfly and Behren's silverspot butterfly are not
specifically protected under any Federal, State or local law. The
California Department of Fish and Game has indicated that it is unable
to protect insects under its current regulations (Pete Bontadelli,
California Department of Fish and Game, in litt., 1990). Although the
San Bruno Mountain Habitat Conservation Plan provides protection from
habitat destruction caused by habitat loss, the unauthorized collection
remains an ongoing threat as discussed in Factor B.
The California Environmental Quality Act and California Endangered
Species Act are the primary environmental legislation passed at the
State level that potentially benefits the conservation of the Alameda
whipsnake. The animal was listed as a threatened species by the State
of California in 1971 (California Department of Fish and Game 1987).
Although these State laws provide a measure of protection to the
species and have resulted in the formulation of mitigation measures to
reduce or offset impacts for projects proposed in certain Alameda
whipsnake habitats, these laws are not adequate to protect the species
in all cases. Numerous activities do not fall under the purview of this
legislation, such as certain projects proposed by the Federal
government and projects falling under State statutory exemptions. Where
overriding social and economic considerations can be demonstrated,
these laws allow project proposals to go forward, even in cases where
the continued existence of the species may be jeopardized or where
adverse impacts are not mitigated to the point of insignificance.
E. Other natural or man-made factors affecting their continued
existence. Use of insecticides could be a threat to the two butterfly
species. Silverspot butterfly larvae are extremely sensitive to
pesticides and even the accumulation of runoff in the soil after
spraying has proven lethal to the larvae of members of the genus
Speyeria (Mattoon et al. 1971). There is the potential that species in
the food chain of the snake would be impacted as well.
High levels of grazing by livestock may pose a threat to the extant
populations of the two butterfly species. Overgrazing could cause
trampling and the ingestion of the larval foodplants and the adult
nectar sources. Low levels of grazing could allow other plants to
outcompete the species required by the callippe and Behren's silverspot
butterflies.
Grazing has adversely affected the habitat of the Alameda whipsnake
in many areas east of the coast range (McGinnis 1992). Livestock
grazing that significantly reduces or eliminates shrub and grass cover
is detrimental to this animal. Most snake species, including the
Alameda whipsnake, avoid open barren areas because of the increased
danger from predators and the lack of prey (McGinnis 1992). Overgrazing
has eliminated otherwise suitable Alameda whipsnake habitat in the area
between Black Diamond Mines Regional Park and Marsh Creek Road in
Contra Costa County and along the west facing slopes of the Altamont
Pass region between Vasco Road and Altamont Pass Road in Alameda
County.
Off-road vehicles and human or horse foot traffic may pose a threat
to the colonies of the two butterfly species. These activities could
result in harassment, injury, or death of individuals of these two
species by trampling or crushing the eggs, larvae, or pupae.
Adequate levels of Viola are critical for the long-term survival of
populations of the two butterfly species (Mattoon, in litt., 1989,
1991). However, California's native grassland and coastal prairie have
been adversely affected by the introduction and invasion of numerous
non-native plants (Heady 1988, Heady et al. 1988). Often these
introduced and alien plants, such as iceplant (Carprobrotus sp.), gum
trees (Eucalyptus spp.), and French broom (Ulex europaeus), outcompete
and largely supplant the native vegetation. Without control and
eradication programs, the introduced and alien taxa will continue to
invade and eliminate the remaining native plant communities, including
the host plants of the callippe and Behren's silverspot butterflies.
Non-native vegetative communities also may eliminate habitat for the
Alameda whipsnake.
Periodic fires are an important factor in maintaining the grassland
and coastal prairie habitat of the silverspot butterflies (Hammond and
McCorkle 1984, Orsak 1980). Without fire, succession eliminates the
foodplants of the larvae of the callippe and Behren's silverspot
butterflies. Periodic ``cool,'' fast-moving fires seem important for
the maintenance of the habitat of the two butterflies. Without fire,
dead grass and other vegetation from previous years may not decay
quickly enough and gradually accumulate to form a thick layer of thatch
that smothers and crowds out the violets. The larvae of the silverspot
butterflies may survive fires that move rapidly through grassland
habitats, in contrast to hotter, slower-moving brush and woodland fires
that may kill them (McCorkle and Hammond 1988, Orsak 1980). Under windy
conditions, grassland fires also burn in patches, which leave
``islands'' of unburned habitat that may contain butterflies.
In small populations, the breeding of closely related individuals
can cause genetic problems, particularly the expression of deleterious
genes (known as inbreeding depression). Individuals and populations
possessing deleterious genetic material are less able to cope with
environmental conditions and adapt to environmental changes, even those
that are relatively minor. Further, small populations are subject to
the effects of genetic drift (the loss of random genetic variability).
This phenomenon also reduces the ability of individuals and populations
to successfully respond to environmental stresses. Overall, these
genetic factors could influence the survivability of the smaller,
genetically isolated populations of each of the three species that are
the subject of this proposed rule.
The callippe silverspot butterfly, Behren's silverspot butterfly,
and the Alameda whipsnake also may suffer from associated effects of
habitat fragmentation. Subdivision of land into smaller blocks of
habitat often is the result of human-related activities, such as
livestock grazing, road construction, and urban development, and serves
to exacerbate the isolation of extant populations. Most of the
populations of the three species proposed for listing herein are
isolated from other conspecific populations. Since recolonization from
neighboring populations is unlikely or impossible, this isolation could
have negative demographic effects, such as low reproductive success.
Also, by further reducing population size and genetic interchange among
populations, habitat fragmentation increases the probability of genetic
drift and inbreeding depression. This may result in less vigorous and
adaptable populations of the three species proposed for listing.
Due to the existence of only small and fragmented populations, the
three species proposed for listing also may be vulnerable to random
fluctuations or variations (stochasticity), such as changes in annual
weather patterns, availability of food, and other natural or human-
induced environmental factors. For example, when the populations of the
callippe and Behren's silverspot butterflies were large, the effects of
a drought or a low abundance of foodplants would not cause the
extinction of these species. However, given the current population
status, events such as drought or low foodplant abundance could cause
their extinction.
The Service has carefully assessed the best scientific and
commercial information regarding past, present, and future threats
faced by these species to propose this rule. As described in more
detail above under Factors A, B, C, D, and E, the available information
indicates that the callippe silverspot butterfly, Behren's silverspot
butterfly, and the Alameda whipsnake should be listed pursuant to
section 4 of the Act. The limited range of these species makes them
vulnerable to overcollecting, rapid urbanization, off-road vehicle use,
inappropriate levels of grazing, and loss of habitat due to invasive
exotic vegetation. Stochastic events, which commonly affect small
isolated populations, also may result in extirpation of some
populations of these species. Ongoing and proposed development projects
pose an imminent threat to Behren's silverspot butterfly and the
Alameda whipsnake throughout their ranges. Extraordinary increases in
human populations and associated pressures for urban development have
rendered existing mechanisms inadequate.
Other alternatives to this action were considered but not preferred
because not listing these species at all or listing them as threatened
would not provide adequate protection and not be in keeping with the
purposes of the Act. Based on this evaluation, the preferred action is
to list the callippe silverspot butterfly (Speyeria callippe callippe),
Behren's silverspot butterfly (Speyeria zerene behrensii), and Alameda
whipsnake (Masticophis lateralis euryxanthus) as endangered. For
reasons discussed below, the Service is not proposing to designate
critical habitat for these animal species at this time.

Critical Habitat

Section 4(a)(3) of the Act, as amended, requires that to the
maximum extent prudent and determinable, the Secretary propose critical
habitat at the time the species is proposed to be endangered or
threatened. The Service finds that designation of critical habitat is
not prudent at this time for the callippe silverspot butterfly,
Behren's silverspot butterfly, and Alameda whipsnake. The Service's
regulations (50 CFR 424.12(a)(1)) state that designation of critical
habitat is not prudent when one or both of the following situations
exist: (1) The species is threatened by taking or other human activity,
and identification of critical habitat can be expected to increase the
degree of such threat to the species; or (2) such designation of
critical habitat would not be beneficial to the species.
As discussed under ``Summary of Factors Affecting the Species,''
the three animals and their habitats are vulnerable to several
activities. The Service is concerned about the impacts of the illicit
commercial trade of the Alameda whipsnake, callippe silverspot
butterfly, and Behren's silverspot butterfly. Unauthorized collecting
is an activity that can be difficult to control because it can be done
in a fairly discrete manner. The precise pinpointing of localities that
would result from publication of critical habitat descriptions and maps
in the Federal Register would increase enforcement problems because the
species proposed herein for listing would be more vulnerable to
collecting, as well as vandalism to their habitat. The potential for
declines due to the collection of these species is so great that any
benefit from the designation of critical habitat is outweighed by the
risk of increased taking. Therefore, the Service finds that designation
of critical habitat for these animals is not prudent. Protection of the
habitat of these species will be addressed through the section 4
recovery process and through the section 7 consultation process.

Available Conservation Measures

Conservation measures provided to species listed as endangered or
threatened under the Endangered Species Act include recognition,
recovery actions, requirements for Federal protection, and prohibitions
against certain activities. Recognition through listing encourages and
results in conservation actions by Federal, State, and private
agencies, groups, and individuals. The Endangered Species Act provides
for possible land acquisition and cooperation with the States and
requires that recovery actions be carried out for all listed species.
Such actions are initiated by the Service following listing. The
protection required of Federal agencies and the prohibitions against
taking are discussed, in part, below.
Section 7(a) of the Act, as amended, requires Federal agencies to
evaluate their actions with respect to any species that is proposed or
listed as endangered or threatened. Regulations implementing this
interagency cooperation provision of the Act are codified at 50 CFR
part 402. Section 7(a)(4) requires Federal agencies to confer with the
Service on any action that is likely to jeopardize the continued
existence of a proposed species. If a species is subsequently listed,
section 7(a)(2) requires Federal agencies to insure that activities
they authorize, fund, or carry out are not likely to jeopardize the
continued existence of such a species or to destroy or adversely modify
its critical habitat. If a Federal action may affect a listed species
or its critical habitat, the responsible Federal agency must enter into
formal consultation with the Service.
No populations of the callippe silverspot butterfly, Behren's
silverspot butterfly, and the Alameda whipsnake are known to occur on
property owned by the Federal government. However, several Federal
agencies would be affected by the listing of these animals. The U.S.
Department of Housing and Urban Development (HUD) may insure housing
loans in areas that presently support the species proposed for listing
herein. Therefore, HUD actions regarding these loans would be subject
to review by the Service under section 7 of the Act. The U.S. Bureau of
Reclamation would be affected by the listing of these animals as this
is the lead agency in administering the permits for the proposed Los
Vaqueros Reservoir. The Army Corps of Engineers' activities or
issuances of permits subject to section 404 of the Clean Water Act
would be subject to the Endangered Species Act section 7 requirements.
The Department of Transportation (Federal Highways Administration) may
be involved with the construction and maintenance of roads and highways
in areas where some or all of these species may be affected, hence this
agency would also be subject to section 7 of the Endangered Species
Act. Any Federal actions that are subject to environmental review under
the National Environmental Policy Act may be subject to the
requirements of section 7 of the Act.
In 1982, a habitat conservation plan (HCP) was completed and a
section 10(a) incidental take permit was issued to the cities of
Brisbane, Daly City, and South San Francisco and the county of San
Mateo for the endangered mission blue butterfly (Icaricia icarioides
missionensis), San Bruno elfin butterfly (Incisalia mossii bayensis),
and San Francisco garter snake (Thamnophis sirtiralis tetrataenia). The
HCP, entitled ``San Bruno Mountain Habitat Conservation Plan'' (U.S.
Fish and Wildlife Service permit number PRT 2-9818), permanently
protects about 1,115 hectares (2,752 acres) of natural habitat at this
site. The conference report on the 1982 amendments to the Endangered
Species Act of 1973 indicates that Congress intended HCPs to encompass
both listed and unlisted species, especially unlisted species that
might later be protected. Although the callippe silverspot butterfly
was not included in the section 10(a) permit, the San Bruno Mountain
HCP included specific considerations and provisions in the event it did
become listed by the Service. Habitat of one of the two known extant
populations of the callippe silverspot butterfly is protected under
this HCP. The permit allows for the loss of animals and habitat through
urban development containing approximately 8 percent of the San Bruno
Mountain population of the callippe silverspot butterfly. Although
habitat is protected, the Service is aware of numerous preserved
specimens of the callippe silverspot butterfly that have been collected
recently on San Bruno Mountain on lands where the animal is not
protected.
The Act and implementing regulations found at 50 CFR 17.21 for
endangered species set forth a series of prohibitions and exceptions
that apply to all endangered wildlife. These prohibitions, in part,
make it illegal for any person subject to the jurisdiction of the
United States to take (including harass, harm, pursue, hunt, shoot,
wound, kill, trap, capture, collect, or attempt any such activity),
import or export, transport in interstate or foreign commerce in the
course of commercial activity, or sell or offer for sale in interstate
or foreign commerce any such species. It also is illegal to possess,
sell, deliver, carry, transport, or ship any such wildlife that was
taken illegally. Certain exceptions can apply to agents of the Service
and State conservation agencies.
Permits may be issued to carry out otherwise prohibited activities
involving endangered animal species under certain circumstances.
Regulations governing permits are at 50 CFR 17.22 and 17.23. Such
permits are available for scientific purposes, to enhance the
propagation or survival of the species, and/or for incidental take in
connection with otherwise lawful activities. Further information
regarding regulations and requirements for permits may be obtained from
the U.S. Fish and Wildlife Service, Office of Management Authority,
Permits Branch, 4401 North Fairfax Drive, room 420C, Arlington,
Virginia 22203-3507 (telephone 703/358-2104).

Public Comments Solicited

The Service intends that any final action resulting from this
proposal will be as accurate and effective as possible. Therefore any
comments or suggestions from the public, other concerned government
agencies, the scientific community, industry, or any other interested
party concerning any aspect of this proposal are hereby solicited.
Comments particularly are sought concerning:
(1) Biological, commercial, trade, or other relevant data
concerning any threat (or the lack thereof) to the callippe silverspot
butterfly, Behren's silverspot butterfly, and Alameda whipsnake;
(2) The location of any additional populations of the callippe
silverspot butterfly, Behren's silverspot butterfly, and Alameda
whipsnake;
(3) Reasons why locations of habitat should or should not be
determined to be critical habitat as provided by section 4 of the Act;
(4) Additional information concerning the range, distribution, and
population size of the callippe silverspot butterfly, Behren's
silverspot butterfly, and Alameda whipsnake; and
(5) Current or planned activities in the subject areas that may
impact the callippe silverspot butterfly, Behren's silverspot
butterfly, and Alameda whipsnake.
Any final decision on this proposal will take into consideration
the comments and any additional information received by the Service,
and such communications may lead to the adoption of a final regulation
that differs from this proposal.
The Endangered Species Act provides for a public hearing on this
proposal. The Service plans to conduct a public hearing, and the dates
and location will be announced at a later date. Requests regarding a
public hearing must be received within 45 days of the date of the
proposal. Such requests must be made in writing (see ADDRESSES
section).

National Environmental Policy Act

The Fish and Wildlife Service has determined that an Environmental
Assessment, as defined under the authority of the National
Environmental Policy Act of 1969, need not be prepared in connection
with regulations adopted pursuant to section 4(a) of the Endangered
Species Act of 1973, as amended. A notice outlining the Service's
reasons for this determination was published in the Federal Register on
October 25, 1983 (48 FR 49244).

References

Arnold, R.A. 1981. A review of endangered species legislation in the
U.S.A. and preliminary research on 6 endangered California
butterflies (Lepidoptera, Lycaenidae). Beh. Ver. Nat. Landsch. Bad.-
Wurtt. Karl. 21:79-96.
Arnold, R.A. 1983. Speyeria callippe (Lepidoptera: Nymphalidae):
Application of information-theoretical and graph-clustering
techniques to analyses of geographic variation and evaluation of
classification. Ann. Ent. Soc. Amer. 76:929-941.
Arnold, R.A. 1985. Geographic variation in natural populations of
Speyeria callippe (Boisduval) (Lepidoptera:Nymphalidae). Pan-Pac.
Ent. 61:1-23.
Boisduval, J.A. 1852. Lepidopteres de la Californie. Ann. Soc. Ent.
France, 2nd series, 10:275-324. (Cited in dos Passos and Grey 1947).
California Department of Fish and Game. 1987. Results of five-year
reviews of 113 California threatened and endangered species. Non-
Game Heritage Program. Sacramento, California.
Collins, N.M., and M.G. Morris. 1985. Threatened swallowtail
butterflies of the world. IUCN Red Data Book. Gland, Switzerland.
401pp.
dos Passos, C.F., and L.P. Grey. 1947. Systematic catalogue of
Speyeria (Lepidoptera, Nymphalidae) with designations of types and
fixations of type localities. Amer. Mus. Nov. 1370.
Duffey, E. 1968. Ecological studies on the large copper butterflies,
Lycaena dispar batavus, at Woodwalton Fen NNR, Huntingdonshire. J.
Appl. Ecol. 5:69-96.
Edwards, W.H. 1869. Descriptions of new species of diurnal
Lepidoptera found within the United States. Trans. Amer. Ent. Soc.
2:369-376.
Gall, L.F. 1984a. Population, structure and recommendations for
conservation of the narrowly endemic alpine butterfly, Boloria
acrocnema (Lepidoptera:Nymphalidae). Biol. Cons. 28:111-138.
Gall, L.F. 1984b. The effects of capturing and marking on subsequent
activity in Boloria acrocnema (Lepidoptera:Nymphalidae), with a
comparison of different numerical models that estimate population
size. Biol. Cons. 28:139-154.
Goldberg, S.R. 1975. Reproduction of the striped racer, Masticophis
lateralis (Colubridae). J. Herp. 9(4):361-363.
Hammerson, G.A. 1978. Observations on the reproduction, courtship,
and aggressive behavior of the striped racer, Masticophis lateralis
euryxanthus (Reptilia, Serpentes, Colubridae). J. Herp. 12(2):253-
255.
Hammond, P.C. 1980. Appendix I. Taxonomy of Speyeria zerene
hippolyta. Pp. 84-91. In D.V. McCorkle, ed. Ecological investigation
report: Oregon silverspot butterfly (Speyeria zerene hippolyta).
U.S. Forest Service, Siuslaw Nat. For., Corvallis, Oregon.
Hammond, P.C. 1986. A rebuttal to the Arnold classification of
Speyeria callippe (Nymphalidae) and defense of the subspecies
concept. J. Res. Lep. 24(3):197-208.
Hammond, P.C., and D.V. McCorkle. 1984. The decline and extinction
of Speyeria populations resulting from human environmental
disturbances (Nymphalidae:Argynninae). J. Res. Lep. 22(4):217-224.
Heady, H. 1988. Valley grassland. Pp. 491-514. In M.G. Barbour and
J. Major, eds. Terrestrial vegetation of California. California
Native Plant Soc. Sp. Pub. No. 9. Sacramento, California.
Heady, H.F., D.W. Taylor, M.G. Barbour, T.C. Foin, M.M. Hektner,
W.J. Barry. 1988. Coastal prairie and northern coastal scrub. Pp.
733-260. In M.G. Barbour and J. Major, eds. Terrestrial vegetation
of California. California Native Plant Soc. Sp. Pub. No. 9.
Sacramento, California.
Howe, W.H. 1975. The butterflies of North America. Doubleday and Co.
Garden City, N.Y. xiii+633pp.
Mattoon, S.O., R.D. Davis, and O.D. Spencer. 1971. Rearing
techniques for species of Speyeria (Nymphalidae). J. Lep. Soc.
25:247-256.
McCorkle, D.V. 1980. Ecological investigation report: Oregon
silverspot butterfly (Speyeria zerene hippolyta). U.S. Forest
Service, Siuslaw Nat. For., Corvallis, Oregon.
McCorkle, D.V., and P.C. Hammond. 1988. Biology of Speyeria zerene
hippolyta (Nymphalidae) in a marine-modified environment. J. Lep.
Soc. 42(3):184-195.
McGinnis, S.M. 1990. Survey for the Alameda whipsnake (Masticophis
lateralis euryxanthus) on the north-facing slope of the Kellogg
Creek watershed west of Vasco Road. Contra Costa County, California.
Jones and Stokes Ass. Sacramento, California. 16pp.
McGinnis, S.M. 1992. Habitat requirements, distribution, and current
status of the Alameda whipsnake (Masticophis lateralis euryxanthus).
Report to the U.S. Fish and Wildlife Service. Sacramento,
California. 26pp.
Morey, S., and H. Bioassay. 1988. California whipsnake Masticophis
lateralis. Page 196. In D.C. Zeiner, W.F. Laudenslayer, and K.E.
Mayer, eds. California's wildlife. Vol. 1. Amphibians and reptiles.
Calif. Depart. of Fish and Game. Sacramento, California. 272pp.
Murphy, D.D. undated. A report on the California butterflies listed
as candidates for endangered status by the United States Fish and
Wildlife Service. Draft report for the California Department of Fish
and Game. Sacramento, California. 60pp.
Murphy, D.D. 1988. Are we studying our endangered butterflies to
death? J. Res. Lep. 26(1-4):236-239.
Orsak, L.J. 1980. The endangered San Francisco silverspot butterfly
of California. Dept. of Zoology and Physiology, Univ. of Wyoming,
Laramie, Wyoming. 4pp.
Reimer, W.J. 1954. A new subspecies of the snake Masticophis
lateralis from California. Copeia 1954:45-58.
Shields, O. 1967. Hilltopping: an ecological study of summit
congregation behavior on a southern California hilltop. J. Res.
Lepidoptera 6:69-178.
Singer, M.C., and P. Wedlake. 1981. Capture does affect probability
of recapture in a butterfly species. Ecol. Ent. 6:215-216.
Stebbins, R.C. 1985. A field guide to western reptiles and
amphibians. Second edition. Houghton Mifflin Pub. Boston,
Massachusetts. xvi+366pp.
Steiner, J. 1990. Bay Area butterflies; the distribution and natural
history of San Francisco region rhopalocera. Master's thesis.
California State University at Hayward. 307pp.
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Steering Committee for San Bruno Mountain. Endangered Species Survey
San Bruno Mountain. Biological Study--1980-1981. Thomas Reid
Associates, Palo Alto, California.

Author

The primary author of this proposed rule is Chris Nagano, staff
entomologist, Sacramento Field Office (see ADDRESSES section).

List of Subjects in 50 CFR Part 17

Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.

Proposed Regulations Promulgation

Accordingly, the Service hereby proposes to amend part 17,
subchapter B of chapter I, title 50 of the Code of Federal Regulations,
as set forth below:

PART 17--[AMENDED]

1. The authority citation for part 17 continues to read as follows:

Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.

2. Section 17.11(h) is amended by adding the following, in
alphabetical order under Reptiles and Insects, to the List of
Endangered and Threatened Wildlife to read as follows:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *
(h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vetebrate population
-------------------------------------------------- Historic range where endangered or Status When listed Critical Special
Common name Scientific name threatened habitat rules
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *
Reptiles

* * * * * * *
Whipsnake (= striped Masticophis lateralis U.S.A. (CA)............ Entire................. E ........... NA NA
racer), Alameda. euryxanthus.

* * * * * * *
Insects

* * * * * * *
Butterfly, Behren's Speyeria zerene U.S.A. (CA)............ NA..................... E ........... NA NA
silverspot. behrensii.

* * * * * * *
Butterfly, callippe Speyeria callippe U.S.A. (CA)............ NA..................... E ........... NA NA
silverspot. callippe.

* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

Dated: January 31, 1994.
Mollie H. Beattie,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 94-2548 Filed 2-3-94; 8:45 am]
BILLING CODE 4310-55-P