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

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

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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.

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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.

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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.

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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