[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.
Thomas Reid Associates. 1982. Final Report to the San Mateo County 
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