Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25813

Example: Bidder X wishes to place the

minimum accepted bid for Market 1. The

standing high bid for this market after Round

19 of the auction is $1 million. The minimum

bid increment is set at ten percent. Thus, the

minimum accepted bid for Market 1 in

Round 20 would be $1.1 million. In Round

20, Bidder X erroneously submits a bid of

$110 million. If Bidder X withdraws it

erroneous bid during the bid withdrawal

period for Round 20, it would be subject to

a bid withdrawal payment of the minimum

bid increment for Round 20, $100,000, or the

difference between $1.1 million and the

subsequent winning bid, whichever is

greater. If Bidder X does not withdraw its bid

until Round 21, and the auction is in Stage

I or Stage II, it would be subject to a bid

withdrawal payment of two times the

minimum bid increment, $200,000, or the

difference between $1.2 million and the

subsequent winning bid, whichever is

greater. If Bidder X waits until Round 22 or

later to withdraw its erroneous bid, it would

be subject to the standard bid withdrawal

payment. Similarly, if the auction is in Stage

III, and Bidder X fails to withdraw its

erroneous bid in Round 20, it would be

subject to the standard bid withdrawal

payment.

19. Under this approach, the required

bid withdrawal payment would be

substantial enough to discourage

strategic placement of erroneous bids

without being so severe as to impose an

untenable burden on bidders. In

addition, the payment is tailored to the

size of the license and the point in the

auction when the mistaken bid was

submitted. For example, if a mistaken

bid is submitted early in a

simultaneous, multiple round auction,

the potential damage to the economic

efficiency of the auction is lower than

if it were submitted during the later

stages of the auction, and the required

bid withdrawal payment would be

correspondingly lower. As an auction

progresses, however, the potential gain

from a strategically-placed erroneous

bid is higher, and the potential damage

to the efficiency of the auction process

is higher. In other words, erroneous bids

cause greater damage to the economic

efficiency of the auction process as

market prices approach their final

valuation. Thus, the cost of submitting

an erroneous bid during the later stages

of an auction is higher than it would be

if it were submitted earlier in an

auction.

20. We have decided to grant ATA

and MAP relief from full enforcement of

the bid withdrawal payment rules.

Specifically, we will utilize the

approach described above to reduce

ATA’s bid withdrawal payment to two

times the minimum bid increment for

license 11P in Round 9, or $45,594.

Similarly, we will utilize the approach

described above to reduce MAP’s bid

withdrawal payment to the minimum

bid increment for license B–380 in

Round 10 of the broadband PCS C block

auction, or $206,400.

21. We delegate to the Wireless

Telecommunications Bureau (the

‘‘Bureau’’) the authority to resolve

similar requests for waiver of the

Commission’s bid withdrawal

provisions. In order for a party to be

eligible for such a waiver, it must

submit a request for waiver

accompanied by a sworn declaration

attesting to the veracity of the factual

circumstances surrounding the

erroneous bid submission. We will

continue to evaluate these requests on a

case-by-case basis. We caution that

relief will not be available to bidders if

there is evidence that they have engaged

in insincere or frivolous bidding or have

otherwise acted in bad faith. We

consider all allegations of bidder

misconduct very seriously.

IV. Ordering Clauses

22. Accordingly, it is ordered That the

waiver request submitted by Atlanta

Trunking Associates, Inc. is granted to

the extent indicated above.

23. It is further ordered That Atlanta

Trunking Associates, Inc. is subject to a

bid withdrawal payment requirement of

$45,594.

24. It is further ordered That the

waiver request submitted by MAP

Wireless, L.L.C. is granted to the extent

indicated above.

25. It is further ordered That MAP

Wireless, L.L.C. is subject to a bid

withdrawal payment requirement of

$206,400.

26. It is further ordered That we

delegate to the Wireless

Telecommunications Bureau the

authority to resolve bid withdrawal

payment waiver requests involving

factual circumstances similar to those

presented here.

Federal Communications Commission.

William F. Caton,

Acting Secretary.

[FR Doc. 96–12967 Filed 5–22–95; 8:45 am]

BILLING CODE 6712–01–M

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018–AC 34

Endangered and Threatened Wildlife

and Plants; Determination of

Threatened Status for the California

Red-Legged Frog

AGENCY: Fish and Wildlife Service,

Interior.

ACTION: Final rule.

SUMMARY: The U.S. Fish and Wildlife

Service (Service) determines threatened

status for the California red-legged frog

(Rana aurora draytonii) pursuant to the

Endangered Species Act of 1973, as

amended (Act). The Service originally

proposed to list the California redlegged frog as endangered, but

information obtained during the

comment period suggests that this taxon

is found in more localities within its

current range than previously identified.

The California red-legged frog is now

found primarily in wetlands and

streams in coastal drainages of central

California. It has been extirpated from

70 percent of its former range. The

California red-legged frog is threatened

within its remaining range by a wide

variety of human impacts, including

urban encroachment, construction of

reservoirs and water diversions,

introduction of exotic predators and

competitors, livestock grazing, and

habitat fragmentation. This rule

implements the Federal protection and

recovery provisions afforded by the Act

for this species.

EFFECTIVE DATE: June 24, 1996.

ADDRESSES: The complete file for this

rule is available for public inspection,

by appointment, during normal business

hours at the U.S. Fish and Wildlife

Service, 2800 Cottage Way, Room E–

1803, Sacramento, CA 95825–1846.

FOR FURTHER INFORMATION CONTACT:

Karen J. Miller, at the above address

(916 979–2725).

SUPPLEMENTARY INFORMATION:

Background

The California red-legged frog (Rana

aurora draytonii) is one of two

subspecies of the red-legged frog (Rana

aurora) found on the Pacific coast. Rana

a. draytonii was first described by Baird

and Girard in 1852 from specimens

collected at or near the City of San

Francisco in 1841 (Storer 1925, Cochran

1961). The California red-legged frog is

the largest native frog in the western

United States (Wright and Wright 1949),
25814 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

ranging from 4 to 13 centimeters (cm)

(1.5 to 5.1 inches (in.)) in length

(Stebbins 1985). The abdomen and hind

legs of adults are largely red; the back

is characterized by small black flecks

and larger irregular dark blotches with

indistinct outlines on a brown, gray,

olive, or reddish background color.

Dorsal spots usually have light centers

(Stebbins 1985). Dorsolateral folds are

prominent on the back. Larvae

(tadpoles) range from 14 to 80

millimeters (mm) (0.6 to 3.1 in.) in

length and the background color of the

body is dark brown and yellow with

darker spots (Storer 1925).

The historical range of the California

red-legged frog extended coastally from

the vicinity of Point Reyes National

Seashore, Marin County, California, and

inland from the vicinity of Redding,

Shasta County, California, southward to

northwestern Baja California, Mexico

(Jennings and Hayes 1985, Hayes and

Krempels 1986). The northern redlegged frog (Rana aurora aurora) ranges

from Vancouver Island, British

Columbia, Canada, south along the

Pacific coast west of the Cascade ranges

to northern California (northern Del

Norte County). Red-legged frogs found

in the intervening area (southern Del

Norte to northern Marin County) exhibit

intergrade characteristics of both R. a.

aurora and R. a. draytonii (Hayes and

Krempels 1986). Systematic

relationships between the two

subspecies are not completely

understood (Hayes and Miyamoto 1984,

Green 1985a, Green 1986, Hayes and

Krempels 1986). However, significant

morphological and behavioral

differences between the two subspecies

suggest that they may actually be two

species in secondary contact (Hayes and

Krempels 1986).

Northern Marin County represents the

approximate dividing line between R. a.

draytonii and the intergrade zone along

the coastal range (Mark Jennings,

National Biological Service, pers.

comm., 1993). California red-legged

frogs found in Nevada (Linsdale 1938,

Green 1985b) were introduced. This rule

does not extend the Act’s protection to

any R. aurora in (1) The State of

Nevada; (2) Humboldt, Trinity, and

Mendocino counties, California; (3)

Glenn, Lake, and Sonoma counties,

California, west of the Central Valley

Hydrological Basin; or (4) Sonoma and

Marin counties north and west of the

Napa River, Sonoma Creek, and

Petaluma River drainages, which drain

into San Francisco Bay, and north of the

Walker Creek drainage, which drains to

the Pacific Ocean.

Several morphological and behavioral

characteristics differentiate California

red-legged frogs from northern redlegged frogs. Adult California red-legged

frogs are significantly larger than

northern red-legged frogs by 35 to 40

mm (1.4 to 1.6 in.) (Hayes and

Miyamoto 1984). Dorsal spots of

northern red-legged frogs usually lack

light centers common to California redlegged frogs (Stebbins 1985), but this is

not a strong diagnostic character.

California red-legged frogs have paired

vocal sacs and call in air (Hayes and

Krempels 1986), whereas northern redlegged frogs lack vocal sacs (Hayes and

Krempels 1986) and call underwater

(Licht 1969). Female California redlegged frogs deposit egg masses on

emergent vegetation so that the egg mass

floats on the surface of the water (Hayes

and Miyamoto 1984). Northern redlegged frogs also attach their egg masses

to emergent vegetation, but the mass is

submerged (Licht 1969).

California red-legged frogs breed from

November through March with earlier

breeding records occurring in southern

localities (Storer 1925). Northern redlegged frogs breed in January to March

soon after the ice melts (Nussbaum et al.

1983). California red-legged frogs found

in coastal drainages are rarely inactive

(Jennings et al. 1992), whereas those

found in interior sites may hibernate

(Storer 1925).

The California red-legged frog

occupies a fairly distinct habitat,

combining both specific aquatic and

riparian components (Hayes and

Jennings 1988, Jennings 1988b). The

adults require dense, shrubby or

emergent riparian vegetation closely

associated with deep (>0.7 meters (m))

still or slow moving water (Hayes and

Jennings 1988). The largest densities of

California red-legged frogs are

associated with deep-water pools with

dense stands of overhanging willows

(Salix spp.) and an intermixed fringe of

cattails (Typha latifolia) (Jennings

1988b). Well-vegetated terrestrial areas

within the riparian corridor may

provide important sheltering habitat

during winter. California red-legged

frogs estivate in small mammal burrows

and moist leaf litter (Jennings and Hayes

1994b). California red-legged frogs have

been found up to 30 m (98 feet (ft)) from

water in adjacent dense riparian

vegetation for up to 77 days (Rathbun et

al. 1993, Galen Rathbun, National

Biological Service, in litt., 1994).

Rathbun (in litt., 1994) found that the

use of the adjacent riparian corridor was

most often associated with drying of

coastal creeks in mid to late summer.

California red-legged frogs disperse

upstream and downstream of their

breeding habitat to forage and seek

estivation habitat. Estivation habitat is

essential for the survival of California

red-legged frogs within a watershed.

Estivation habitat, and the ability to

reach estivation habitat can be limiting

factors in California red-legged frog

population numbers and survival.

Estivation habitat for the California

red-legged frog is potentially all aquatic

and riparian areas within the range of

the species and includes any landscape

features that provide cover and moisture

during the dry season within 300 feet of

a riparian area. This could include

boulders or rocks and organic debris

such as downed trees or logs; industrial

debris; and agricultural features, such as

drains, watering troughs, spring boxes,

abandoned sheds, or hay-ricks. Incised

stream channels with portions narrower

than 18 inches and depths greater than

18 inches may also provide estivation

habitat.

Egg masses that contain about 2,000 to

5,000 moderate-sized (2.0 to 2.8 mm

(0.08 to 0.11 in.) in diameter), dark

reddish brown eggs are typically

attached to vertical emergent vegetation,

such as bulrushes (Scirpus spp.) or

cattails (Typha spp.) (Jennings et al.

1992). California red-legged frogs are

often prolific breeders, laying their eggs

during or shortly after large rainfall

events in late winter and early spring

(Hayes and Miyamoto 1984). Eggs hatch

in 6 to 14 days (Jennings 1988b). In

coastal lagoons, the most significant

mortality factor in the pre-hatching

stage is water salinity (Jennings et al.

1992). One hundred percent mortality

occurs in eggs exposed to salinity levels

greater than 4.5 parts per thousand

(Jennings and Hayes 1990). Larvae die

when exposed to salinities greater than

7.0 parts per thousand (Mark Jennings,

National Biological Service, in litt.,

1994). Larvae undergo metamorphosis

3.5 to 7 months after hatching (Storer

1925, Wright and Wright 1949, Jennings

and Hayes 1990). Of the various life

stages, larvae probably experience the

highest mortality rates, with less than 1

percent of eggs laid reaching

metamorphosis (Jennings et al. 1992).

Sexual maturity normally is reached at

3 to 4 years of age (Storer 1925, Jennings

and Hayes 1985), and California redlegged frogs may live 8 to 10 years

(Jennings et al. 1992).

The diet of California red-legged frogs

is highly variable. Larvae probably eat

algae (Jennings et al. 1992). Hayes and

Tennant (1985) found invertebrates to

be the most common food items of adult

frogs. Vertebrates, such as Pacific tree

frogs (Hyla regilla) and California mice

(Peromyscus californicus), represented

over half of the prey mass eaten by

larger frogs (Hayes and Tennant 1985).

Hayes and Tennant (1985) found
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25815

juvenile frogs to be active diurnally and

nocturnally, whereas adult frogs were

largely nocturnal. Feeding activity likely

occurs along the shoreline and on the

surface of the water (Hayes and Tennant

1985).

The California red-legged frog has

sustained a 70 percent reduction in its

geographic range in California as a

result of several factors acting singly or

in combination (Jennings et al. 1992).

Habitat loss and alteration,

overexploitation, and introduction of

exotic predators were significant factors

in the California red-legged frog’s

decline in the early to mid 1900s. It is

estimated that California red-legged

frogs were extirpated from the Central

Valley floor before 1960. Remaining

aggregations (assemblages of one or

more individuals, not necessarily a

viable population) of California redlegged frogs in the Sierran foothills

became fragmented and were later

eliminated by reservoir construction,

continued expansion of exotic

predators, grazing, and prolonged

drought. Within the Central Valley

hydrographic basin, only 14 drainages

on the Coast Ranges slope of the San

Joaquin Valley and one drainage in the

Sierran foothills are actually known to

support or may support California redlegged frogs, compared to over 60

historic locality records for this basin (a

77 percent reduction). The pattern of

disappearance of California red-legged

frogs in southern California is similar to

that in the Central Valley, except that

urbanization and associated roadway,

large reservoir (introduction of exotic

predators), and stream channelization

projects were the primary factors

causing population declines. In

southern California, California redlegged frogs are known from only five

locations south of the Tehachapi

Mountains, compared to over 80 historic

locality records for this region (a

reduction of 94 percent).

California red-legged frogs are known

to occur in 243 streams or drainages in

22 counties, primarily in the central

coastal region of California. The current

number of occupied drainages

represents information obtained during

the public comment period and reevaluation of Service records. This reevaluation resulted in the compilation

of a threat matrix for all drainages

known to support California red-legged

frogs (U.S. Fish and Wildlife Service

1995). The term ‘‘drainage’’ will be used

to describe named streams, creeks, and

tributaries from which California redlegged frogs have been observed. For

purposes of this final rule, a single

occurrence of California red-legged frog

is sufficient to designate a drainage as

occupied by, or supporting California

red-legged frogs. Monterey (32), San

Luis Obispo (36), and Santa Barbara (36)

counties support the greatest number of

currently occupied drainages.

Historically the California red-legged

frog was known from 46 counties, but

the taxon is now extirpated from 24 of

those counties (a 52 percent reduction

in county occurrences). In seven of the

22 occupied counties (32 percent),

California red-legged frogs are known

from a single occurrence. The most

secure aggregations of California redlegged frogs are found in aquatic sites

that support substantial riparian and

aquatic vegetation and lack exotic

predators (e.g., bullfrogs (Rana

catesbeiana), bass (Micropterus spp.),

and sunfish (Lepomis spp.)). Only three

areas within the entire historic range of

the California red-legged frog may

currently support more than 350 adults,

Pescardero Marsh Nature Preserve (San

Mateo County), Point Reyes National

Seashore (Marin County), and Rancho

San Carlos (Monterey County). The San

Francisco Airport drainage location,

identified in the proposed rule as

containing over 350 individuals, is now

thought to be nearly extirpated. Threats,

such as expansion of exotic predators,

proposed residential development, and

water storage projects, occur in the

majority of drainages known to support

California red-legged frogs.

Previous Federal Action

On January 29, 1992, the Service

received a petition from Drs. Mark R.

Jennings and Marc P. Hayes, and Mr.

Dan Holland to list the California redlegged frog (Rana aurora draytonii). The

petition specified endangered or

threatened status by distinct drainages

(watersheds) within the range of the

species. On October 5, 1992, the Service

published a 90-day petition finding (57

FR 45761) that substantial information

had been presented indicating the

requested action may be warranted.

Public comments were requested and a

review of the species’ status was

initiated. The California red-legged frog

had been included as a Category 1

candidate species in the Service’s

November 21, 1991, Animal Notice of

Review (56 FR 58804). Category 1

candidates (now known simply as

candidates) are species for which the

Service has sufficient information on

biological vulnerability and threat to

support proposals to list them as

endangered or threatened. On July 19,

1993, the Service published a 12-month

finding on the petitioned action (58 FR

38553). This finding indicated that

listing of the California red-legged frog

was warranted and that a proposed rule

would be published promptly. On

February 2, 1994 (59 FR 4888), the

Service published a proposal to list the

California red-legged frog as an

endangered species. Based on new

information received during the

comment period on the proposed rule,

the Service now determines the

California red-legged frog to be a

threatened species.

Summary of Comments and

Recommendations

In the February 2, 1994 proposed rule

(58 FR 4888) and associated

notifications, all interested parties were

requested to submit factual reports or

information that might contribute to

development of a final rule. Appropriate

State agencies and representatives,

County and City governments, Federal

agencies and representatives, scientific

organizations, and other interested

parties were contacted and requested to

comment. Newspaper notices were

published in the San Francisco

Chronicle on February 9, 1994, and the

Sacramento Bee on February 10, 1994,

both of which invited public comment.

The Service received eight written

requests for a public hearing. Three

requests came from the Mosquito and

Vector Control Districts of Glenn,

Sutter/Yuba, and Butte counties.

Additional requests came from William

Hazeltine, a private consultant; the

California Cattlemen’s Association; the

Cambria Community Services District;

the United Residential Lot Owners of

Cambria, Inc.; and Price, Postel, and

Parma, a Santa Barbara law firm. As a

result, the Service published a notice of

public hearing on April 8, 1994 (59 FR

16792), and reopened the comment

period until May 27, 1994. Appropriate

State agencies and representatives,

County and City governments, Federal

agencies and representatives, scientific

organizations, and other interested

parties were contacted regarding the

hearing. A newspaper notice of the

public hearing was published in the

Sacramento Bee on April 25, 1994,

which invited general public comment.

A public hearing was conducted at the

Radisson Hotel in Sacramento,

California on May 12, 1994. Testimony

was taken from 6:00 p.m. to 8:00 p.m.

Seventeen individuals testified at the

hearing.

During the comment periods, the

Service received 72 comments (i.e.,

letters and oral testimony) from 57

individuals or agencies. Of the 31

commenters that stated a position, 22

(71 percent) supported listing and 9 (29

percent) did not.

Support for the listing was expressed

by one State agency (California
25816 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

Department of Parks and Recreation)

and 18 other interested parties. Three

commenters recommended listing the

California red-legged frog as threatened.

Opposition to the listing was expressed

by two mosquito abatement or vector

control districts and seven other

interested parties. Of the 26 respondents

indicating no position on the listing,

several expressed concern regarding the

impact of listing.

Written comments and oral

statements obtained during the public

hearing and comment periods are

combined in the following discussion.

Opposing comments and other

comments questioning the rule can be

placed in 10 general groups based on

content. These categories of comment,

and the Service’s response to each, are

listed below.

Issue 1: Insufficiency of Scientific Data

Comment: Several commenters stated

that insufficient data are available to

warrant listing of the California redlegged frog. They suggested that the

distribution of the California red-legged

frog is more widespread and that many

more sites may exist than were reported

in the proposed rule because surveying

within the historic range of the taxon

has not been complete. One commenter

suggested that only easily accessible

areas on the coast seemed to have been

surveyed and if a watershed approach

had been taken, the range of the species

would be greater than 30 percent of its

historical range. Another commenter

suggested that many surveys were done

in drought years, which would bias the

data.

Service Response: The Service

mapped the current range of the

California red-legged frog based on

survey results. Wherever a watershed

was known to support California redlegged frogs, the entire watershed was

included as being within the species’

current range. The only watersheds that

were not included in their entirety are

those in the Sierra Nevada where the

upper reaches are too high in elevation

to provide habitat for the California redlegged frog, and portions of watersheds

located on the Central Valley floor. In

the Coast Ranges, watersheds lacking

information on California red-legged

frogs were included within the current

range of the California red-legged frog

from Marin County south to Ventura

County.

Over the last 15 years, the petitioners

have conducted multiple surveys,

visiting each survey site a minimum of

three times, to determine the status of

the California red-legged frog

throughout its entire range. The

petitioners rechecked 75 percent of the

historic sites in the coastal region of the

range of the California red-legged frog

and all suitable habitat within the

species historic range in the Central

Valley and Sierra Nevada foothills

including all but one of the historic

sites. This site was surveyed by another

herpetologist, Dave Martin (Jennings,

pers. comm., 1995). In surveying

suitable habitat, access to some areas

was denied by private landowners. Even

so, surveyors were able to obtain access

to all major drainages within their

survey area (Jennings, pers. comm.,

1995). Many of the surveys were

conducted between 1986 and 1990,

which were considered drought years.

However, in the majority of cases

reasons other than drought were

considered responsible for the absence

of frogs (Jennings, pers. comm., 1995).

Where drought was thought to be the

case, repeat surveys were performed in

subsequent wet years (Jennings, pers.

comm., 1995). Approximately half of the

sites surveyed were along roadsides and

easily accessible. The remaining sites

were difficult to access, often requiring

strenuous hikes (Jennings, pers. comm.,

1995). Surveying by the petitioners and

others is ongoing in many portions of

the State.

Surveys conducted by other

researchers support the conclusions of

the petitioners. Extensive surveying has

been conducted in years with and

without drought conditions in Sierran

national forests by David Martin

(University of California, Santa Barbara,,

pers. comm., 1994); Santa Clara County

and the foothills of the western Sierra

Nevada between Modesto and Fresno by

the Coyote Creek Riparian Station (in

litt., 1993); the Sacramento Valley, San

Joaquin Valley and inner Coast Ranges

by the University of California at Davis

(H. Bradley Shaffer, University of

California, Davis, in litt., 1994); Santa

Cruz County by the University of

California at Santa Cruz (Nauman 1992);

Santa Cruz and San Mateo counties

(Mike Westphal, Coyote Creek Riparian

Station, 1995), and the Point Reyes

Peninsula by the National Park Service

(Gary Fellers, National Biological

Service, in litt., 1994).

As a result of these surveys and

additional information received during

the public comment period following

publication of the proposed rule, 54

new localities of California red-legged

frogs were identified. The majority of

these sightings, however, are within the

current range of the California redlegged frog as identified in the proposed

rule. The exceptions are the discovery of

California red-legged frogs in the Sierran

foothills (Butte County, Pinkard Creek),

the Transverse mountain range (Los

Angeles county near Palmdale), Sulphur

Springs Creek in Solano County, and

Mine Creek in Fresno County; the latter

two representing minor range

extensions to the east. The Service is

confident that the Central Valley floor,

Sierra Nevada foothills, and southern

California (south of the Tehachapi

Mountains) have been surveyed

sufficiently to draw the conclusion that

California red-legged frogs have been

extirpated or nearly extirpated from

these regions. These three regions

comprise over 70 percent of the

California red-legged frog’s historic

range.

Section 4(b)(1)(A) of the Act requires

that a listing determination be based on

the best scientific and commercial data

available. The Service bases this listing

determination on data collected over a

period of 15 years by the petitioners and

numerous other qualified herpetologists.

All data indicate a downward trend in

the range of the California red-legged

frog and a preponderance of small,

fragmented aggregations of frogs. The

viability of the remaining California redlegged frog aggregations is threatened by

numerous factors which are discussed

in detail in this rule. The Service

maintains, therefore, that sufficient data

are available to warrant listing the

California red-legged frog. However,

because the Service received significant

additional information on locations of

California red-legged frog aggregations

within their current range during the

comment period, listing the taxon as

threatened rather than endangered is

deemed more appropriate.

Comment: Another commenter stated

that the conclusion in the proposed rule

that 75 percent of the species’ remaining

range is threatened by one or more

factors has no basis in scientific fact and

is not supported by any substantial

scientific evidence.

Service Response: The proposed rule

stated that the California red-legged frog

has been extirpated from 75 percent of

the historic range of the taxon. Because

of the inclusion of 54 additional streams

or drainages known to support

California red-legged frogs, the final rule

has been revised to state that extirpation

has occurred in 70 percent of the

historic range. The commenter

misinterpreted the information in the

proposed rule. The estimate of

extirpated range is based on information

published in the literature and

presented to the Service by the

petitioners and other herpetologists,

survey biologists, and consultants.

Comment: One commenter stated that

an article in the March 1, 1994, San

Ramon Valley Times reported that the

East Bay Regional Park District had not
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25817

surveyed for frogs on its properties.

Given that the District comprises over

75,000 acres, the commenter believed

that this lack of information was a

significant data gap.

Service Response: East Bay Regional

Park District biologists and private

consultants in 1990, 1993, and 1994

surveyed an estimated 95 percent of

District properties that could contain

California red-legged frog habitat

(Joseph DiDonato, East Bay Regional

Park District, pers. comm. and in litt.,

1994; Karen Swaim, LSA Associates,

Inc., in litt., 1994). California red-legged

frogs were found in 5 of 53 District

parks. Included in the survey results

were 8 streams or drainages not

previously known to be inhabited by

California red-legged frogs.

Comment: One commenter stated that

the information on California red-legged

frog locations in Alameda County is

probably not complete. The commenter

contended that California red-legged

frogs are probably not as rare in

Alameda County as purported in the

proposed rule.

Service Response: California redlegged frogs are known from 21

drainages in the county. Many other

drainages in the county that have been

surveyed by the East Bay Regional Park

District and LSA Associates, Inc. harbor

only bullfrogs. Of the 22 counties

known to support aggregations of

California red-legged frogs, Alameda

County ranks ninth in total number of

drainages supporting the taxon. Over

half of the known frog aggregations in

the county, however, are threatened by

various factors including exotic

predators, urban development, off-road

vehicles, and grazing. While it is

possible that some California red-legged

frog locations have yet to be discovered,

the Service believes it is unlikely that

California red-legged frogs inhabit more

than the 21 known drainages in

Alameda County.

Comment: One commenter stated that

the Service’s data on locations of

California red-legged frogs does not

match information contained in the

California Department of Fish and Game

Natural Diversity Database (NDDB).

Service Response: The researchers

who petitioned the Service to list this

species and the Service have reviewed

all data available from the NDDB

regarding locations of California redlegged frogs. The NDDB currently

contains approximately 122 records of

California red-legged frogs. The

petitioners have determined current and

historic range of the taxon from 1,205

museum records and 250 records from

other sources coupled with extensive

field checking of records. All locations

identified in the NDDB prior to 1992

were field checked by the petitioners.

All new locations identified in the

NDDB from 1992 to the present have

been added to the Service’s analysis of

the current range of the California redlegged frog. These additional records

have not appreciably extended the

currently known range of the taxon.

Comment: Several commenters noted

that the proposed rule indicated

uncertainty in biology, life cycle, habitat

requirements, and predators of the

California red-legged frog, including

identifying where frogs overwinter,

where post-metamorphic frogs feed,

what larvae eat, and site specific

predators. The commenters believed

that listing of the taxon was not

warranted until these data gaps were

filled.

Service Response: The Service has

relied on the best available scientific

and commercial data in making this

listing determination. The Service

concurs that many aspects of the

biology, predator-prey interactions, and

microhabitat requirements of the

California red-legged frog are not

completely understood. This is true for

most species of wildlife, including

common species that have been studied

extensively. Sufficient knowledge of the

biology and habitat requirements of the

California red-legged frog exists to

identify suitable habitats for the taxon,

and document population sizes, threats,

and its status over time. It is this latter

information along with the scientific

and commercial information that is used

in determining whether or not to list a

species under section 4(a) of the Act. A

complete understanding of the biology

and microhabitat requirements of a

listed species are most important in the

recovery process. However, a significant

delay in listing a species due to large,

long-term biological or ecological

research efforts could compromise the

survival of the California red-legged

frog.

Comment: Several commenters stated

that the proposed rule cites livestock

grazing as a major factor in the decline

of the California red-legged frog, but

fails to offer site-specific examples of

habitat degradation and ‘‘take’’ of the

species as a result of grazing. One

commenter thought that the Service,

therefore, could not restrict grazing

practices in any way if the species is

listed.

Service Response: The proposed rule

includes livestock grazing as one of

many factors affecting the California

red-legged frog, and ranks it as a

contributing factor, rather than as a

major factor. No site specific studies

have been done that document the

decline and disappearance of California

red-legged frogs once grazing is

introduced into an area. Most evidence

on the effects of grazing on the

California red-legged frog is

circumstantial. However, extensive

research has been done on the effects of

livestock grazing on the aquatic

environment. As stated in the proposed

rule, the petitioners found that grazing

occurred at all historic sites known to

support California red-legged frogs in

the Central Valley hydrologic basin.

Combining this information with

information about the habitat

preferences of the California red-legged

frog leads to the logical conclusion that

grazing, where it has dramatically

altered California red-legged frog

habitat, has played a role in the decline

of this taxon.

Comment: One commenter stated that

the petition to list the California redlegged frog relies heavily on personal

observations, personal communications,

and unpublished data. Although the

Service is required to base listings on

the ‘‘best available data’’, the

commenter believed that such

information did not meet the definition

of scientific data because they would be

impossible to verify. Three commenters

recommended that the proposed listing

action be halted and a comprehensive,

unbiased scientific review of the status

of the California red-legged frog be

initiated and published.

Service Response: The researchers

who petitioned the Service to list the

California red-legged frog are

acknowledged experts on this taxon as

evidenced by numerous peer reviewed

publications on the subject. The

majority of the personal observations

cited in the petition refer to specific

aspects of California red-legged frog

biology, which is relevant to the species’

management, but less important in

determining species’ status. Many of the

references to unpublished data in the

petition refer to distribution and status

information that had been collected by

the petitioners as part of their ongoing

research to follow the status of the

California red-legged frog. Much of their

status information is supported by

surveys conducted by numerous other

qualified herpetologists. The Service,

therefore, finds that the data presented

by the petitioners are credible and have

been verified by other experts in the

field.

Comment: Several commenters

requested that prior to listing the

California red-legged frog, the Service

quantify impacts to the various life

stages of the frog caused by storm

damage repair, flood control efforts,

reservoir creation, diking and ditching,
25818 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

regular road maintenance, disease,

livestock grazing, off-road vehicle use,

timber harvest, predation by native and

non-native predators, competition,

ultraviolet radiation, water quality,

agricultural practices, recreation,

reproductive interference, drought,

wildfires, flooding, and natural

population fluctuations.

Service Response: Section 4(a)(1) of

the Act requires the Service to evaluate

threats to the species. The Service is

unable to quantify how each of the

above individual threats has impacted

the California red-legged frog. Many

threats work synergistically to cause

population declines. Thus, the effect of

each threat cannot be quantified

separately. The above factors are

believed to contribute to significant

population declines. Completing

research in all these areas prior to listing

the California red-legged frog could

seriously compromise its survival

because of lengthy time periods needed

to quantify impacts. Further research in

these areas, however, would aid the

Service in future recovery actions for

this species.

Comment: One commenter

recommended that the Service delineate

the current range and habitat locations

of the California red-legged frog in San

Joaquin County prior to listing.

Service Response: The Service has

delineated the current range and

specific habitat locations of California

red-legged frogs in San Joaquin County.

Two locations of the California redlegged frog occur in San Joaquin

County, both in western portions of the

county. The distribution map for the

California red-legged frog includes all

portions of western San Joaquin County

that lie on the east slope of the coast

range, west of Highway 580.

Comment: One commenter

recommended that the Service quantify

California red-legged frog population

numbers in lotic and lentic habitat and

establish management and recovery

programs for each habitat type prior to

listing the taxon.

Service Response: A recovery plan

will be prepared for the California redlegged frog after the taxon is listed.

Completion of the above recommended

research would be most appropriate

during the recovery process for the

California red-legged frog.

Issue 2: Causes for California RedLegged Frog Decline

Comment: Several commenters

suggested that ultraviolet-B (UV–B)

radiation or estrogen mimics, which

have been implicated in the current

observed worldwide decline in

amphibians, may be significant causes

of observed declines in the range and

numbers of California red-legged frogs.

Service Response: The Service has

reviewed the paper by Blaustein et al.

(1994) regarding the possible effect of

UV–B radiation on the eggs of three

amphibian species, the Pacific treefrog

(Pseudacris regilla), western toad (Bufo

boreas), and Cascade frog (Rana

cascadae). Our review focused on

results reported for the Cascade frog,

because this species is most closely

related to the California red-legged frog.

Results of tests on Cascade frog eggs

from two sites showed mixed results.

One site showed that hatching success

of R. cascadae was greater under

sunlight lacking UV–B than under

unfiltered sunlight. At the second site,

however, the hatching success under

UV–B blocking filters was not

significantly different from success

under unfiltered sunlight. Thus, these

data do not present sufficient evidence

of a correlation between UV–B radiation

and hatching success in the related

Cascade frog.

Because UV–B radiation would have

greater adverse effects at higher

elevations, the Cascade frog, which is a

higher elevation species than the

California red-legged frog, would be

expected to be more severely affected by

UV–B radiation, if indeed this is an

important factor. Also, because the

California red-legged frog attaches its

egg masses to aquatic vegetation and

prefers aquatic habitats with

overhanging vegetation, the effects of

UV–B radiation would be expected to be

less than for the Cascade frog, whose

eggs are typically laid in shallow open

water (Nussbaum et al. 1983). In

addition, the majority of the observed

decline in the California red-legged frog

occurred prior to the late 1970’s, which

is when noticeable declines in

amphibian species began in western

North America (M. Jennings, pers.

comm, 1994).

A number of recent studies address

certain contaminants that disrupt

biological processes by mimicking the

effects of naturally produced hormones,

such as the female hormone estrogen

(Raloff 1994). This phenomenon has

been implicated in the recent

worldwide decline in amphibians.

Several studies have been done on

reptiles, including the American

alligator (Alligator mississippiensis) and

red-eared slider turtle (Pseudemys

scripta elegans). To our knowledge, no

studies have been done on amphibians.

The potential effects of estrogen mimics

on California red-legged frogs are

unknown. In addition, the majority of

the observed decline in the California

red-legged frog occurred prior to the late

1970’s, which is when noticeable

declines in amphibian species began in

western North America (M. Jennings,

pers. comm, 1994).

Comment: Several commenters stated

that evidence suggesting mosquitofish

(Gambusia affinis) are significant

predators of California red-legged frog

larvae is not strong. The commenters

stated that infrequent co-occurrence of

fish and frogs does not explain potential

causation. Other factors may be

involved in population decline

including microhabitat features of

wetlands, which cannot be successfully

duplicated in a laboratory setting. Also

in a natural setting, the vulnerable stage

for California red-legged frog tadpoles

(February through April) normally does

not coincide with the time of year when

mosquitofish numbers are high.

Microhabitat usage may not overlap.

The commenters pointed out that there

are sites where mosquitofish and

California red-legged frogs coexist. One

commenter objected to the mosquitofish

being included as a verified predator of

California red-legged frogs and

especially as an organism more harmful

than introduced centrarchid fishes or

bullfrogs.

Service Response: The Service is

aware of only one study that has

indicated that in laboratory settings

mosquitofish prey on the larvae of

California red-legged frogs (Schmieder

and Nauman 1994). However, there is a

strong correlation between the absence

of California red-legged frogs and the

presence of mosquitofish in the field.

The Service is aware of several sites

where mosquitofish and California redlegged frogs are currently coexisting.

This evidence suggests that the

relationship between mosquitofish and

California red-legged frogs is complex.

Additional research clearly is needed to

more fully understand how these two

species interact. The final rule has been

revised to reflect current knowledge on

this issue. The Service cannot determine

whether mosquitofish are harmful to

California red-legged frogs.

Comment: Several commenters

disagreed that mosquitofish could be

significant predators of California redlegged frogs. They cited observations in

mosquitofish ponds of mosquitofish

numbers decreasing as a result of

infestations by bullfrogs. These

commenters noted that no predation of

bullfrog tadpoles by mosquitofish was

observed.

Service Response: Mosquitofish

would not be expected to prey on larval

bullfrogs because of the apparent

olfactory rejection (unpalatability) of

bullfrog larvae by predatory fish (Kruse

and Francis 1977). California red-legged
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25819

frogs lack this olfactory rejection effect,

and, therefore, cannot be compared to

bullfrogs (Schmieder and Nauman

1994).

Comment: One commenter pointed

out that widespread, large scale use of

mosquitofish in California began in the

mid to late 1970’s, and therefore, could

not be responsible for the extirpation of

California red-legged frogs from the

Central Valley floor because frogs were

extirpated from this region before 1960.

Service Response: The Service

concurs that mosquitofish were not a

major factor in the decline and

disappearance of California red-legged

frogs from the Central Valley floor. The

proposed and final rules point to

overharvest combined with the loss of

over 3,800,000 acres of wetlands as the

major reasons for extirpation of

California red-legged frogs from the

valley floor (Frayer, et al. 1989).

However, significant introductions of

mosquitofish began in the Central

Valley as early as 1922 (Moyle 1976).

Thus it is possible that mosquitofish

played a role in the decline of California

red-legged frogs on the Central Valley

floor.

Comment: Two commenters stated

that mosquitofish are not significant

predators of California red-legged frogs

because the two species coexist in

wetlands in Shasta and Colusa counties.

Service Response: California redlegged frogs were extirpated from Shasta

and Colusa counties before 1960

(Jennings et al. 1992).

Comment: Several commenters

provided more specific or additional

information on threats to California redlegged frogs within their current range.

Several commenters provided

information regarding potential threats,

including road kills, current harvesting

of California red-legged frogs for food,

construction activities, and poor

management of flood control basins.

Service Response: These comments

have been noted and included in this

final rule.

Comment: One commenter stated that

massive predation by introduced

predators, not grazing, is in large part

responsible for any observed population

declines in the California red-legged

frog. Similarly, another commenter

stated that the decline and

disappearance of California red-legged

frogs in the foothill portions of Madera,

Fresno, and Mariposa counties were due

to dispersal of bullfrogs into stock

ponds, and not due to grazing. The

commenter stated that California redlegged frogs coexisted with grazing until

about 1940, when bullfrogs were

introduced into the San Joaquin Valley.

Service Response: Of the identified

threats facing the California red-legged

frog, introduced predators, including

bullfrogs, are considered to be a

significant and widespread threat. Over

50 percent of streams and drainages

inhabited by California red-legged frogs

are known to support bullfrogs or other

exotic predators in some portion of that

drainage. Grazing, however, can

threaten the California red-legged frog

where grazing pressure results in

dramatic changes in riparian and

wetland habitat. As discussed in this

final rule, California red-legged frogs

generally prefer densely-shaded wetland

habitats, whereas bullfrogs prefer more

open wetland habitats. Overgrazing in

riparian areas, therefore, exacerbates the

threat of bullfrog expansion by creating

habitat bullfrogs prefer.

Comment: One commenter stated that

profitable livestock operations and high

quality riparian habitat areas are not

mutually exclusive. The commenter

points to Point Reyes National Seashore

as an example of where cattle grazing

and California red-legged frogs

successfully coexist. The commenter

stressed that livestock grazing is the

only economic activity in the region that

provides large contiguous areas of open

space.

Service Response: The Service

concurs that properly managed livestock

grazing can be compatible with

preservation of California red-legged

frog populations. California red-legged

frogs and cattle grazing are able to

coexist at Point Reyes National Seashore

because the National Park Service

maintains tight control over grazing

pressure (Gary Fellers, National

Biological Service, pers. comm., 1994).

The Service acknowledges that

preservation and proper management of

open space, especially in riparian areas,

is a fundamental requirement in the

survival and recovery of the California

red-legged frog.

Comment: One commenter stated that

the single most devastating change in

wildlife habitat in California in the last

200 years has been urbanization. The

commenter thought that the proposed

rule had not given this factor proper

recognition, but instead condemned

activities such as livestock grazing.

Service Response: The proposed rule

and this final rule do not single out

livestock grazing as the greatest threat to

the California red-legged frog, but

instead discusses all factors known or

likely to threaten California red-legged

frog populations. The proposed and

final rules list numerous proposed

developments that threaten remaining

populations of California red-legged

frogs. The Service believes urbanization,

as well as agriculture, have caused

substantial changes in wildlife habitat

in California. This is especially the case

in the Central Valley, which historically

was the stronghold of the California redlegged frog.

Comment: Several commenters stated

that climatic conditions (i.e., drought

and above average rainfall events) were

more to blame for California red-legged

frog declines than human activities,

including timber harvest and historic

commercial harvest of the California

red-legged frog itself. One commenter

noted that dramatic declines in historic

frog harvest information could indicate

that the species is subject to wide

variation in population numbers due to

climatic conditions rather than an

indication of overharvest. The

commenter requested that an historical

survey of the variations in population

numbers due to climatic changes be

undertaken prior to publication of a

final rule.

Service Response: The rule includes a

discussion of natural factors, such as

drought and heavy rainfall events, that

are known to adversely affect California

red-legged frog populations. It is

difficult to separate the effects of natural

events from human activities when

attempting to determine the cause for a

population’s decline in a particular area.

A single factor is seldom the cause of

the decline of a species. Many of the

factors discussed in the proposed rule

and this final rule work synergistically.

Regardless of which factors resulted in

historic population declines, California

red-legged frog populations in the

Central Valley and Sierra Nevada, in

particular, could not rebound from this

decline because at the same time their

wetland and riparian habitat was being

converted to agricultural land and urban

areas.

Populations of most species are cyclic

in nature, responding to such natural

factors as weather events, disease, and

predation. Natural events, however,

including long-term drought or extreme

rainfall, have less of a negative effect

overall on a species when that species

is widely and continuously distributed.

Where populations are small,

fragmented, or isolated by various

human-related factors including habitat

loss, water development, and water

diversion, these populations are more

vulnerable to extirpation by stochastic

or random events and cumulative

effects.

It is likely that over time, California

red-legged frogs experienced wide

variations in population size as a result

of climatic events. A historical survey

dating back to the early 1900’s focusing

on the variation in frog population
25820 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

numbers due to climatic changes is not

possible because no range wide

population information was collected

on the California red-legged frog dating

back that far. If such data existed,

conclusions drawn from such an

historical survey would be tenuous. The

many adverse human factors that have

contributed to California red-legged frog

population declines since 1900 would

cloud any analysis of the effects of

drought or high rainfall events.

Comment: One commenter disagreed

with the conclusion that pre-1900

overharvesting of the California redlegged frog in the Central Valley led to

their decline. The commenter stated that

other known historical factors were not

cited in the proposed rule.

Service Response: No studies were

conducted in the late 1800’s or early

1900’s documenting the cause or causes

of declines in California red-legged frog

populations in the Central Valley.

Extremely high numbers of California

red-legged frogs reported in the San

Francisco markets followed by a

collapse of the market around the turn

of the century strongly suggests that

commercial harvesting had a significant

effect on California red-legged frog

numbers. The Central Valley, and

particularly the San Joaquin Valley,

were reported at the time to be prime

habitat for the California red-legged frog.

The proposed rule and this final rule

reported all known historical factors

that may have contributed to the decline

of California red-legged frogs in the

Central Valley. Overharvesting was

certainly not the only factor impacting

California red-legged frog populations.

Conversion of over 3,800,000 acres of

wetland and riparian habitats in the

Central Valley to agricultural land and

urban areas began during the same

period, resulting in the elimination of

California red-legged frogs from the

valley floor before 1960.

Comment: Several commenters stated

that many of the urban development

projects referred to in the proposed rule

in the Central Coast region may or may

not be constructed during the next 5 or

10 years.

Service Response: The Service

recognizes that all projects proposed are

not necessarily completed. This may be

due to lack of proper permits necessary

for construction, or interruption of

planning efforts. The fact that projects

have been proposed presents a future

threat to California red-legged frog

aggregations in the central coast region,

especially if these projects result in

direct or indirect riparian habitat

degradation.

Comment: One commenter stated the

proposed rule incorrectly includes the

Cambria Meadows drainage as an area

where California red-legged frog habitat

has been directly degraded through

stream reductions to accommodate new

urban growth.

Service Response: This final rule

states that proposed urban and/or

recreational development could degrade

or eliminate California red-legged frog

habitat in Cambria Meadows Creek.

Comment: One commenter thought

that support of the proposed listing

appeared to rely heavily on conditions

reported for the north coast of San Luis

Obispo County.

Service Response: Neither the

proposed rule nor this final rule rely

heavily on conditions reported for the

north coast of San Luis Obispo County

in determining the need to list the

California red-legged frog. San Luis

Obispo County contains the third

highest number of drainages known to

support California red-legged frogs.

Although California red-legged frog

aggregations in streams in the county

are threatened by a variety of factors,

many other counties have comparable

threats that are reported in the proposed

and final rule.

Comment: Several commenters were

concerned about the accuracy of the

conclusions drawn by Rathbun et al.

(1991) as cited in the proposed rule

regarding the combined effects of water

extraction and drought on populations

of California red-legged frogs in lower

Santa Rosa Creek. Numerous

commenters presented data both to

support and refute the hypothesis that

water extractions from Santa Rosa Creek

have significantly changed its

hydrology.

Service Response: The Service

recognizes that controversy exists

regarding the environmental effects of

water extraction from Santa Rosa Creek.

The information and data presented by

the many commenters on this subject

will be thoroughly reviewed by Service

field biologists during recovery

planning efforts and when consulting on

any proposed projects that could

adversely affect California red-legged

frogs in Santa Rosa Creek.

Ground water and surface water

supplies in Santa Rosa Creek are finite.

Unchecked water extraction may exceed

input and significantly reduce the

availability of riparian and aquatic

habitat for California red-legged frogs in

the future. Drought accentuates the

effect, and if not considered in water

planning, overallocation of stream flows

and overdraft of groundwater resources

combined with long-term drought could

result in permanent elimination of

California red-legged frogs from all or a

large part of the drainage.

Comment: Several commenters

pointed out that although California redlegged frogs were absent from lower

Santa Rosa Creek during the drought

(Rathbun et al. 1991), red-legged frogs

have been sighted in recent years in the

lower reaches of the creek, presumably

because of the above average rainfall in

the winter of 1992–1993. California redlegged frogs, which were known to

inhabit upper reaches of the creek

during the drought years, were

presumed to have traveled downstream

to reoccupy former habitat. One

commenter suggested that the Service

should study an entire watershed prior

to concluding that the California redlegged frog is threatened in that

watershed.

Service Response: The Service is

aware that California red-legged frogs

occur in the upper reaches of Santa Rosa

Creek. Santa Rosa Creek is one of 32

drainages in San Luis Obispo County

known to provide habitat for the

California red-legged frog. Neither the

Service nor Rathbun et al. (1991) have

concluded that California red-legged

frogs have disappeared from Santa Rosa

Creek. Rathbun et al. (1991) refers only

to conditions in the lower portions of

the creek and lagoon.

The Service recognizes that the

California red-legged frog is capable of

repopulating former habitat when

rainfall returns. However, other factors,

including overallocation of water, may

exacerbate the effects of drought

through loss of riparian habitat or

increased salinity in coastal lagoons.

Where appropriate riparian or wetland

habitat is degraded over the long-term

by these hydrologic modifications,

repopulation by California red-legged

frogs in altered portions of the drainage

is not possible regardless of whether

red-legged frogs occur in upstream

reaches. As portions of the drainage

become unsuitable habitat for California

red-legged frogs, isolated aggregations of

frogs become more susceptible to

stochastic extinction. The Service is not

basing this listing determination on the

status of the California red-legged frog

in any one specific watershed, but

rather on the continuing population

decline and threats to the remainder of

its range.

Comment: One commenter noted that

California red-legged frogs persist in

upstream portions of Carmel River

despite the fact that bullfrogs are found

in the lower river and two reservoirs.

The commenter felt that this evidence

refuted the assertion that California redlegged frog populations usually

disappear from a drainage within 5

years after a reservoir is built.
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25821

Service Response: The proposed rule

and this final rule state that California

red-legged frogs generally are extirpated

from downstream portions of a drainage

1 to 5 years after filling of a reservoir.

Hayes and Jennings (1988), which is

cited as the source of this information,

does not present this cause and effect

relationship as an absolute. The authors

state that this relationship depends on

the size of the drainage. In larger

drainages, isolated populations can

persist upstream. This final rule has

been revised to clarify this point.

Comment: One commenter thought

that too much emphasis was given to

the negative impacts of salinity levels in

coastal lagoons. Natural overwash of salt

water into coastal lagoons makes these

areas unreliable habitat for California

red-legged frogs.

Service Response: The Service

acknowledges that coastal lagoons

provide unreliable habitat for California

red-legged frogs because of natural

salinity changes caused by wave

overwash. However, large populations

of California red-legged frogs do occur

in coastal lagoons, with Pescadero

Marsh supporting one of the largest

remaining populations. Therefore, the

larger lagoon systems should not be

discounted. Overallocation of stream

water resources intensifies the effect of

drought on coastal lagoon populations,

which over the long-term could result in

changes in lagoon vegetation and

hydrology that are unfavorable to

California red-legged frogs.

Comment: One commenter suggested

that competition with tree frogs and

foothill yellow-legged frogs (Rana

boylii) may be a contributing factor in

the decline of California red-legged frog.

Service Response: No evidence exists

in the literature to support the theory

that competition between California redlegged frogs and Pacific tree frogs or

foothill yellow-legged frogs resulted in

California red-legged frog declines.

Issue 3: Economic and Environmental

Effects of Listing

Comment: Several commenters stated

that listing of the California red-legged

frog may act to limit or curtail existing

uses of private property, and therefore,

a takings implication assessment should

be made prior to taking any final action.

Service Response: Regarding

Executive Order 12630, Governmental

Actions and Interference with

Constitutionally Protected Property

Rights, the Attorney General has issued

guidelines to the Department of the

Interior (Department) on

implementation of the Executive Order.

Under these guidelines, a special rule

applies when an agency within the

Department is required by law to act

without exercising its usual discretion—

that is, to act solely upon specified

criteria that leave the agency no

discretion.

In this context, the Service might be

subject to legal challenge if it

considered or acted upon economic

data. In these cases, the Attorney

General’s guidelines state that Takings

Implications Assessments (TIAs) shall

be prepared after, rather than before, the

agency makes the decision upon which

its discretion is restricted. The purpose

of TIAs in these special circumstances

is to inform policy makers of areas

where unavoidable taking exposures

exist. Such TIAs shall not be considered

in the making of administrative

decisions that must, by law, be made

without regard to their economic

impact. In enacting the Act, Congress

required the Department to list species

based solely upon scientific and

commercial data indicating whether or

not they are in danger of extinction. The

Act does not allow the Service to

withhold a listing based on concerns

regarding economic impact. The

provisions of the guidelines relating to

nondiscretionary actions clearly are

applicable to the determination of

threatened status for the California redlegged frog.

Comment: Several commenters

expressed concern about an adverse

effect of listing the California red-legged

frog on the economy. Another

commenter stated that the economic

impact of listing the California redlegged frog would be devastating to an

already sluggish State economy.

Service Response: Under section

4(b)(1)(A) of the Act, a listing

determination must be based solely on

the best scientific and commercial data

available. The legislative history of this

provision clearly states the intent of

Congress to ‘‘ensure’’ that listing

decisions are ‘‘* * * based solely on

biological criteria and to prevent

nonbiological considerations from

affecting such decisions * * *’’ H. R.

Rep. No. 97–835, 97th Cong., 2d Sess.

19 (1982). As further stated in the

legislative history, ‘‘* * * economic

considerations have no relevance to

determinations regarding the status of

species * * *’’ Id. at 20. Because the

Service is specifically precluded from

considering economic impacts, either

positive or negative, in a final decision

on a proposed listing, the Service need

not evaluate or consider the economic

impacts of listing this species.

Comment: One commenter suggested

that the researchers who petitioned the

Service to list this species were using

the Endangered Species Act as a method

of furthering their personal agenda to

remove livestock from public and

private rangeland.

Service Response: The Service is

unaware that the researchers who

petitioned the Service to list the

California red-legged frog have a

personal agenda to remove livestock

from public and private rangeland.

Management of livestock on rangelands

is one of many possible alternatives

available to address adverse effects of

grazing on California red-legged frog

populations. For example, minor

alterations in management practices and

fencing of key riparian areas are two

alternatives that preserve grazing

opportunities while protecting

California red-legged frogs.

Comment: Numerous commenters

stated that the Service should consider

the human health implications of

eliminating the use of mosquitofish,

draining of wetlands, and insecticides to

control mosquitos.

Service Response: California redlegged frogs require still or slow-moving

water with dense emergent and

overhanging riparian vegetation for

survival. Sites with these habitat

attributes are often at great distances

from urban areas and are not regularly

stocked with mosquitofish or otherwise

managed to control mosquitos.

Therefore, at the majority of remaining

sites inhabited by California red-legged

frogs, mosquito control is not likely to

be an issue. Where mosquitos are an

issue, other biological control methods

are available and may be more

appropriate in California red-legged frog

habitat. These methods include

application of several species of bacteria

(Bacillus sp.), and more recently,

application of a fungus (Lagenidium

giganteum), which apparently attacks

and kills only mosquitos. The Service is

willing to work with mosquito and

vector control districts to minimize

conflicts between public health and the

California red-legged frog.

The Service concludes that listing the

California red-legged frog as a

threatened species is not likely to

hinder efforts of any Mosquito and

Vector Control Districts to control

mosquitos in California.

Comment: One commenter stated that

cessation or curtailment of water

releases from reservoirs to accommodate

the California red-legged frog could

adversely impact other species,

including several species of anadromous

fish.

Service Response: If changes in

reservoir release schedules are needed,

the Service, in conjunction with the

California Department of Fish and

Game, will consider the needs of all
25822 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

species that could be affected as

recommendations are made.

Issue 4: Designation of Critical Habitat

Comment: Several commenters

recommended that the Service designate

critical habitat for the California redlegged frog so that it would be easier for

interested parties to locate known and

additional populations of the species,

and thus, contribute to an accurate

determination of the need for

protection. One commenter

recommended designation of critical

habitat as an additional way to protect

California red-legged frogs on private

land. One commenter stated that an

economic analysis should be conducted

prior to designating critical habitat.

Service Response: The Service has

determined that designation of critical

habitat for the California red-legged frog

would be more detrimental than

beneficial to the species. Concern for the

potential ‘‘take’’ of the species (as

defined in the Act) through acts of

vandalism has been expressed by the

petitioners and other parties (see further

discussion in ‘‘Summary of Factors

Affecting the Species’’ (Factor B) and

‘‘Critical Habitat’’ sections, below).

Revealing of the precise locations of

California red-legged frog habitat, as

required through critical habitat

designation, would make the species

more vulnerable to vandalism and

unauthorized takings. The Service has

determined that designation of critical

habitat is not prudent for the California

red-legged frog, therefore, preparation of

an economic analysis is not required.

However, the Service has identified

recovery units for the species.

Designation of critical habitat would

not necessarily provide additional

protection for California red-legged frog

aggregations on private land. Critical

habitat legally applies only to Federal

lands or activities on non-federal lands

regulated, sponsored, or funded by a

Federal agency. For example,

designation of critical habitat on private

grazing lands would not provide added

protection against the impacts of grazing

on California red-legged frog habitat

because there is no federal nexus.

Conversely, activities on private lands

that are authorized, funded or carried

out by a Federal agency, such as permit

actions authorized under section 404 of

the Clean Water Act, would require

consultation with the Service if the

activity was expected to adversely affect

a Federally listed endangered or

threatened species. This would apply

regardless of whether critical habitat

was designated or not.

Issue 5: National Environmental Policy

Act

Comment: Several commenters stated

that the proposal to list the California

red-legged frog requires preparation of

an Environmental Impact Statement

(EIS) under the National Environmental

Policy Act (NEPA). Another commenter

stated that an Environmental

Assessment may be necessary to

determine the effects of the listing on

other native species, disease-producing

organisms, and humans.

Service Response: The Service need

not prepare environmental assessments

or environmental impacts statements

pursuant to the National Environmental

Policy Act (NEPA) for reasons outlined

in the Federal Register on October 25,

1983 (48 FR 49244). Basically the listing

of a species is exempt as a matter of law

from NEPA review. Listing decisions are

based on biological, not sociological or

economic considerations. This view was

upheld in the court case Pacific Legal

Foundation v. Andrus, 657 F. 2d 829

(1981).

Issue 6: Alternate Listing Status

Recommended

Comment: Several commenters

recommended that the California redlegged frog be listed as a threatened

rather than an endangered species in

various watersheds because measures

are already being taken through Federal,

State, and/or private efforts to protect

California red-legged frog habitat, or

because the numbers of California redlegged frogs in these watersheds are

greater and the threats less than in other

watersheds within the California redlegged frog’s distribution. One

commenter provided examples of

specific streams including—(1) Sespe

Creek, where 31 miles within the Forest

Service’s Sespe Wilderness Area have

been designated as Wild and Scenic,

and a portion of Sespe Creek is included

within the Sespe Condor Sanctuary; and

(2) Piru Creek, where flow releases have

been modified to protect the Arroyo

southwestern toad (Bufo microscaphus

californicus), an endangered species.

Service Response: Additional

information received during the public

comment period regarding new

locations of California red-legged frogs

confirmed that the taxon is more

widespread within its current range

than previously thought. The existence

of 54 new drainage localities, and some

drainages with non-imminent threats,

indicates that listing as a threatened

rather than an endangered species is

presently more appropriate for the

California red-legged frog. The species is

not now in danger of extinction

throughout all or a significant portion of

its range in the near future, however,

evidence does indicate that it may

become endangered.

The Service acknowledges that a

portion of Sespe Creek is designated as

‘‘Wild and Scenic’’ under the Wild and

Scenic River Act, 16 U.S.C. 1271 et seq.,

and that activities such as reservoir

development or channelization, may be

prohibited in this area. The Service also

recognizes that the portion of the creek

within the Sespe Condor Sanctuary may

be protected in certain ways. However,

designation as such does not eliminate

all potential threats to the California

red-legged frog. For example,

designation as Wild and Scenic does not

protect against invasion of bullfrogs or

other exotic predators, which are known

to occur in other portions of Sespe

Creek. Planned reservoir development

downstream of the Wild and Scenic

portion of Sespe Creek increases the

likelihood that bullfrogs and introduced

fishes could disperse into upstream

protected portions of the creek. Also,

the Wild and Scenic designation does

not eliminate recreational uses of the

creek, including such activities as

fishing, camping, mountain biking, and

horseback riding. The Sespe Creek

portion of the Sespe Condor Sanctuary

is not closed to recreational use by the

public.

On Piru Creek, studies suggest that

modified water releases from Lake

Pyramid over the last four years have

resulted in increased Arroyo

southwestern toad populations (Cat

Brown, Fish and Wildlife Service, pers.

comm., 1994). No research has been

conducted to document the effect of

these flow releases on California redlegged frogs.

Although the status of the California

red-legged frog is not uniform

throughout its range, the overall picture

is one of a threatened species. Recovery

planning and consultations under

section 7 of the Act will take into

account the status of the California redlegged frog within recovery units of its

range (see ‘‘Available Conservation

Measures’’ section).

Comment: One commenter from Santa

Barbara County recommended that the

California red-legged frog be listed as a

threatened species because the current

range of the California red-legged frog is

broad and includes most of its historic

range. Another commenter thought that

the current range of the California redlegged frog, which is 300 miles north to

south, did not fit the definition of an

endangered species.

Service Response: Section 3(20) of the

Act defines a threatened species as one

which is likely to become an
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25823

endangered species within the

foreseeable future throughout all or a

significant portion of its range.

Although the current range of the

California red-legged frog encompasses

less than 30 percent of its historic

distribution, new information received

during the public comment period

suggests that California red-legged frogs

are more widespread within their

current range than previously believed.

For this reason and the fact that 17

percent of the remaining drainages

occupied by frogs are not known to be

imminently threatened, the Service has

concluded that the California red-legged

frog more appropriately meets the

definition of a threatened species.

Comment: Several commenters

requested that California red-legged

frogs in specific drainages of the Central

Coast or the entire Central Coast be

exempt from endangered species status

because California red-legged frogs seem

to be adequately managed in this area,

have not shown population declines, or

have fewer exotic species problems.

Service Response: Section 3(16) the

Act defines the term ‘‘species’’ to

include any subspecies of fish, wildlife,

or plants, and any distinct population

segment of any species of vertebrate fish

or wildlife that interbreeds when

mature. California red-legged frog

aggregations in certain drainages of the

central coast of California or in the

entire central coast region do not

constitute distinct vertebrate population

segments. The Service cannot exclude

these areas and intends to list the taxon

as threatened throughout its range.

Issue 7: Research and Education Needs

Comment: Several commenters

recommended the following research

topics be explored in relation to

conservation of the California red-legged

frog: (1) Seasonal utilization of patchy

habitats for breeding, refugia and

estivation; (2) migration timing; (3)

estivation timing; (4) surveying

methodology in marginal habitat; and

(5) the effects of pesticide and herbicide

runoff.

Service Response: These comments

have been noted and will be considered

during preparation of a recovery plan

for the California red-legged frog.

Comment: One commenter committed

to assisting the Service with cooperative

research on mosquitofish/California redlegged frog interactions.

Service Response: The Service

concurs fully with the need for further

research in this area and acknowledges

the commenter’s commitment to this

effort.

Comment: One commenter asked if a

program could be developed that would

allow for variable treatment/

management of California red-legged

frog habitat that was found to produce

significant numbers of mosquitoes.

Service Response: Because California

red-legged frog habitat is variable, it is

likely that management programs for

mosquitoes will also be variable and

depend on the situation under review.

Research into the effects of various

methods of mosquito control on

California red-legged frogs should aid

the Service in any recovery planning

undertaken for the taxon.

Comment: One commenter

recommended a number of ways to

educate the general public regarding

listed species and elicit their support,

including publishing information in

trade journals, posting signs at storm

drains to discourage dumping of

contaminants, reevaluating the need for

channelized creeks, educating the

public regarding the effects of bullfrogs

on native amphibians, teaching classes

in grade schools, starting riparian

revegetation projects, and encouraging

participation of landowners by

providing incentives.

Service Response: The comments

have been noted. The Service welcomes

recommendations from the public on

how to further the purposes of the

Endangered Species Act. The Service

has implemented many of these

recommendations in regard to other

listed species and will give them due

consideration in public education

programs related to recovery of the

California red-legged frog.

Issue 8: Systematic Relationships

Between Red-legged Frog Subspecies

Comment: Several commenters

questioned the Service’s exclusion of

the intergrade zone between the

northern red-legged frog (Rana aurora

aurora) and the California red-legged

frog (Rana aurora draytonii) in

northwestern California. They argued

that this segment of the subspecies’

range does not constitute a distinct

population segment and, therefore,

cannot be excluded from the listing

package. One commenter suggested that

the Service excluded this segment of the

subspecies’ range to make the

subspecies distribution seem smaller

and in greater need of protection.

Another commenter suggested that

the two subspecies are actually different

populations of the same species

displaying morphological differences

due to climatic and habitat variations. In

this case, the population numbers and

distribution of the species would be

much greater and the need for listing

nonexistent.

Service Response: The California redlegged frog is a recognized subspecies of

the red-legged frog (Storer 1925,

Cochran 1961, Stebbins 1985). As

discussed in the background section of

this rule, the range of the California redlegged frog is the vicinity of Point Reyes

National Seashore, Marin County,

California, coastally and from the

vicinity of Redding, Shasta County,

California, inland southward to

northwestern Baja California, Mexico

(Jennings and Hayes 1985, Hayes and

Krempels 1986). Red-legged frogs found

in the intergrade zone from northern

Marin County to southern Del Norte

County are not considered a population

segment of the California red-legged

frog. At this time, researchers have not

assigned the intergrade zone to either

subspecies.

Among other differences, red-legged

frogs within the intergrade zone are

distinct morphologically from either

subspecies of Rana aurora. The

California red-legged frog possesses

paired vocal sacs whereas the northern

red-legged frog lacks vocal sacs. Most

red-legged frogs found in the intergrade

zone from northern Marin County to

southern Del Norte County possess only

one vocal sac. Based on this pronounced

morphological difference in red-legged

frogs in the intergrade zone, some

researchers have concluded that the

California and northern red-legged frogs

may be two distinct species, and that

the intergrade zone represents a zone of

secondary contact or hybridization

between the two species (Hayes and

Krempels 1986). Genetic research has

been proposed to clarify systematic

relationships (i.e., to determine if R. a.

aurora and R. a. draytonii should be

classified as two species or should

remain as subspecies) and allow a more

precise identification of the northern

limits of the geographic distribution of

the California red-legged frog (Jennings

et al. 1992). In addition, habitat within

the majority of the intergrade zone

(moist evergreen/hardwood forest) is

more indicative of habitat preferred by

the northern red-legged frog. Thus, if the

Service were to assign the intergrade

zone to either subspecies based on

habitat preference alone, the intergrade

zone would be more appropriately

placed within the range of the northern

red-legged frog.

Comment: One commenter noted that

the California Academy of Sciences has

66 specimens identified as Rana aurora

draytonii that were collected from

Redwood National Park in Humboldt

County between 1911 and 1940. The

commenter stated that more specific

identification of herpetological

subspecies would be needed to
25824 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

determine the boundary of California

red-legged frogs as far north as Del Norte

County.

Service Response: The specimens

referred to by the commenter were

identified as R. a. draytonii in the 1940’s

based on size, skin characteristics, and

prominence of dorsolateral folds as

described by Camp (1917). More recent

research (see Hayes and Miyamoto 1984,

Hayes and Krempels 1986), has

identified vocal sac condition as a

distinct morphological characteristic

differentiating the two subspecies.

Using these new findings, the

researchers who petitioned the Service

to list the species have reviewed the

specimens in question and found that

they should have been identified as

intergrades between R. a. aurora and R.

a. draytonii. As discussed above,

research currently underway is designed

to further refine the northern boundary

of the California subspecies’ range.

Comment: Another commenter

suggested that the listing package

should only consider red-legged frogs at

the species level, and, therefore, if redlegged frogs were temporarily

eliminated from some part of their range

in California, frogs from other areas

would recolonize suitable habitat.

Service Response: Section 3(15) of the

Endangered Species Act defines a

species to include ‘‘any subspecies of

fish or wildlife or plants* * *’’.

Therefore, listing of a recognized

subspecies is authorized in the Act.

The ability of red-legged frogs to

migrate from one drainage to another

would be dependent upon the distance,

topography and habitat type through

which the frogs would be required to

migrate. Considering the Mediterranean

climate in California, with its seasonal

dryness, it is unlikely that red-legged

frogs could very successfully migrate

long distances to repopulate formerly

occupied habitat.

Issue 9: Existing Regulatory

Mechanisms

Comment: Several commenters

believed that existing regulations (i.e.,

Clean Water Act, California

Environmental Quality Act) and

monitoring by several Federal agencies

are providing adequate protection for

the California red-legged frog, and,

therefore, listing is not needed.

Service Response: The Service

believes that existing regulatory

mechanisms do not currently provide

adequate protection for the California

red-legged frog. A discussion of existing

regulations can be found below in

Factor D of the ‘‘Summary of Factors

Affecting the Species’’ section and the

‘‘Available Conservation Measures’’

section.

Issue 10: Miscellaneous

Comment: One commenter pointed

out that the Cambria Community

Services District acts responsibly in

protecting Santa Rosa and San Simeon

Creek, including reductions in pumping

during drought periods, promoting

retrofit programs to reduce water usage,

research into desalination alternatives

and reverse osmosis treatment of

wastewater, and approval of riparian

habitat improvements.

Service Response: The Service

acknowledges the District’s efforts to

protect stream flows and the natural

environment of Santa Rosa and San

Simeon Creeks. However, the Service

has identified threats in these drainages

and other drainages as well.

Comment: One commenter indicated

that mosquito abatement districts have

modified their mosquitofish planning

protocol to carefully consider the

introduction of mosquitofish in areas

inhabited by listed species.

Service Response: The Service

acknowledges the program

modifications made by many mosquito

abatement districts to protect listed

species and their habitat.

Summary of Factors Affecting the

Species

After a thorough review and

consideration of all information

available, the Service has determined

that the California red-legged frog

should be listed as a threatened species.

Procedures found at section 4 of the Act

(16 U.S.C. 1533 et seq.) and regulations

(50 CFR Part 424) promulgated to

implement the listing provisions of the

Act were followed. A species may be

determined to be an endangered or

threatened species due to one or more

of the five factors described in section

4(a)(1). These factors and their

application to the California red-legged

frog (Rana aurora draytonii) are as

follows:

A. The present or threatened

destruction, modification, or

curtailment of its habitat or range.

Herpetologists have noted the decline or

extirpation of California red-legged frogs

from the San Francisco Bay area (Sean

J. Barry, University of California, Davis,

in litt., 1992; Robert C. Stebbins,

University of California, Berkeley, in

litt., 1993; John S. Applegarth,

herpetologist, in litt., 1993; Ed Ely,

herpetologist, in litt., 1993), the Salinas

River drainage (Lawrence E. Hunt,

University of California, Santa Barbara,

in litt., 1993), the San Luis Obispo,

Santa Barbara, and Ventura County area

(Aryan I. Roest, California Polytechnic

State University, San Luis Obispo, in

litt., 1993; Samuel S. Sweet, University

of California, Santa Barbara, in litt.,

1993), southern California (Patrick

McMonagle, herpetologist, in litt., 1993;

John D. Goodman, zoologist, in litt.,

1992; Robert B. Sanders, San Bernardino

County Museum, in litt., 1992; John

Stephenson, U.S. Forest Service, in litt.,

1993; Michael C. Long, Eaton Canyon

Park Nature Center, in litt., 1992; Joseph

F. Copp, herpetologist, in litt., 1993;

Glenn R. Stewart, California Polytechnic

University, Pomona, in litt., 1993;

Robert Fisher, University of California,

Davis, in litt., 1993), central California

(Martin R. Brittan, California State

University, Sacramento, in litt., 1993),

and the northern and southern Sierra

Nevada foothills (Jay Wright, Feather

River College, Quincy, in litt., 1993;

Alan M. McCready, California State

University, Sacramento, in litt., 1992).

These observations from

herpetologists and data provided by the

researchers who petitioned the Service

to list the species indicate that the

California red-legged frog has sustained

a reduction of over 70 percent in its

historic geographic range in California.

Large aggregations of greater than 350

adults have been documented from only

four areas. These areas included

Pescadero Marsh Natural Preserve in

coastal San Mateo County, Point Reyes

National Seashore in Marin County,

canals west of San Francisco

International Airport in the San

Francisco Bay area (Jennings et al.

1992), and Rancho San Carlos in

Monterey County (Jeff Froke, Rancho

San Carlos, in litt., 1994). The

aggregation west of San Francisco

International Airport is now thought to

be extirpated (U.S. Fish and Wildlife

Service, 1995; David Mullen, private

consultant, pers. comm., 1994).

Habitat loss and alteration are the

primary factors that have negatively

affected the California red-legged frog

throughout its range. For example, in

the Central Valley of California, over 90

percent of historic wetlands have been

diked, drained, or filled primarily for

agricultural development and

secondarily for urban development (U.S.

Fish and Wildlife Service, 1978).

Wetland alterations, clearing of

vegetation, and water diversions that

often accompany agricultural

development make aquatic sites

unsuitable for California red-legged

frogs. Urbanization with its associated

roadway, stream channelization, and

large reservoir construction projects has

significantly altered or eliminated

California red-legged frog habitat, with

the greatest impact occurring in
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25825

southern California. The majority of

extant localities are isolated and

fragmented remnants of larger historical

populations.

Current and future urbanization poses

a significant threat to the California redlegged frog. Sixty-five drainages (27

percent of the known occurrences) are

associated with urbanization threats

(U.S. Fish and Wildlife Service, 1995).

Proposed urban developments include

the East County Area Plan in Alameda

County, which involves development of

up to 52,000 acres, and projects

currently proposed in the Ruby Hills/

Arroyo Del Valle watershed and south

Livermore Valley; Reservoir Canyon

ponds in Santa Clara County; Alamo,

Shadow, and Brookside Creeks in

Contra Costa County; the Carmel River

in Monterey County; and the Santa Ynez

River in Santa Barbara County. In Santa

Cruz County, a proposed commuter rail

project linking Santa Cruz to

Watsonville could increase urban

development in southern portions of the

county (Patricia O’Keefe, R.A.I.L.S., in

litt., 1994). In San Luis Obispo County,

one of three counties with numerous

drainages supporting California redlegged frogs, proposed residential and/

or recreational development adjacent to

San Simeon, Santa Rosa, San Juan, and

Cambria Meadows Creeks and Estrella

and Salinas Rivers could degrade or

eliminate California red-legged frog

habitat. Updates to area plans for the

North Coast, San Luis Obispo, and Paso

Robles/Atascadero areas in San Luis

Obispo County propose rezoning of over

240,000 acres primarily for urban

development. Between the cities of

Ventura and San Luis Obispo,

development already has eliminated

California red-legged frogs from at least

eight drainages along the coast (G.

Rathbun and M. Jennings, in litt., 1993).

Loss of habitat and decreases in

habitat quality will occur as a result of

on-site degradation of the stream

environment and/or riparian corridor, or

through modification of instream flow.

Where streams or wetlands occur in

urban areas, the quality of California

red-legged frog habitat is degraded by a

variety of factors. Among these factors

are introduction of exotic predators,

elimination of streambank vegetation,

collecting, and loss of upland habitat.

Water projects, which accompany

urban and agricultural growth, have had

a negative effect on California redlegged frogs and their habitat. The

construction of large reservoirs, such as

Lake Oroville, Whiskeytown Reservoir,

Don Pedro Reservoir, Lake Berryessa,

San Luis Reservoir, Lake Silverwood,

Lake Piru, Pyramid Lake, and Lower

Otay Lake, have eliminated California

red-legged frog habitat or fragmented

remaining aggregations (Jennings et al,.

1992).

The timing and duration of water

releases from reservoirs, particularly on

the central California coast, can render

a stream unsuitable for California redlegged frog reproduction (M. Jennings,

in litt., 1993) and maintain populations

of exotic predators in downstream areas

that would normally be dry in summer

(S. Sweet, in litt., 1993). Reservoirs are

typically stocked with predatory species

of fish and bullfrogs. These species

often disperse into surrounding

California red-legged frog habitat

disrupting natural community

dynamics. Hayes and Jennings (1988)

found that California red-legged frogs

generally were extirpated from

downstream portions of a drainage 1 to

5 years after filling of a reservoir. In

some larger drainages, however, isolated

California red-legged frog populations

have persisted upstream. A discussion

of exotic predators appears below in

Factor C: ‘‘Disease or predation.’’

A variety of proposed water projects

threaten remaining California red-legged

frog aggregations. Construction of major

reservoirs is proposed on Los Banos

Creek (Merced County), with Orestimba

Creek (Stanislaus County) as an

alternative reservoir site (California

Department of Water Resources and the

U.S. Bureau of Reclamation, 1990), and

on Kellogg Creek (Contra Costa County)

(Contra Costa Water District, 1993).

These drainages represent three of 14

sites remaining in the Central Valley

hydrographic basin with known or

potential localities of California redlegged frogs. On the Salinas River along

the central coast, raising the height of

Salinas Dam (Santa Margarita Lake) is

proposed in San Luis Obispo County.

Reservoir construction at this site may

allow exotic predators access to

formerly secure aggregations of

California red-legged frogs isolated in

upper portions of the watershed (L.

Hunt, in litt., 1993). Other large

reservoir projects proposed in California

red-legged frog habitat include the

Upper Nacimiento River Project and

Arroyo Seco Dam Project in Monterey

County. In Santa Barbara and Ventura

counties, proposed dams on the Santa

Ynez River, Sisquoc River, and Sespe

Creek also would eliminate or degrade

California red-legged frog habitat (Sam

Sweet, pers. comm., 1993).

Water diversions, groundwater well

development, and stock pond or small

reservoir construction projects degrade

or eliminate habitat. Diverting water

from natural habitats to these projects

disrupts the natural hydrologic regime.

During periods of drought, reduced

availability of water within natural

drainages combined with drawdown

from the impoundments, disrupts

reproduction, foraging, estivation and

dispersal (U.S. Fish and Wildlife

Service, 1995) (see Factor E, ‘‘Other

natural or man-made factors affecting its

continued existence’’ below for

additional discussion of the effects of

drought). Proposed or existing water

diversions on the central coast

potentially affect the following

drainages: San Simeon, Santa Rosa, Van

Gordon, Villa, San Luis Obispo, Pico,

and Little Pico Creeks, Arroyo del

Puerta, and Arroyo Laguna in San Luis

Obispo County; the Carmel and Salinas

Rivers in Monterey County; and Canada

del Refugio in Santa Barbara County.

Most waterways on the south coast of

Santa Barbara County are diverted to

agriculture and other uses, leaving some

completely desiccated (Brian Trautwein,

Santa Barbara Urban Creeks Council, in

litt., 1994). Stock ponds and small

reservoirs also support populations of

exotic fishes and bullfrogs (G. Rathbun

and M. Jennings, in litt., 1993). The

proposed coastal branch of the State

Water Project is likely to result in a

number of adverse effects to California

red-legged frogs in many of the 24 areas

receiving State water. These effects

include, (1) altered water regimes in

existing and any proposed delivery

facilities of individual water districts,

(2) spills, leaks, malfunctions, and

operational errors that lead to

introduction of exotic predators into

isolated stream segments currently

occupied by California red-legged frogs,

and (3) indirect effects associated with

expanded urbanization.

Storm damage repair and flood

control maintenance on streams are

current threats to California red-legged

frogs. Routine flood control

maintenance includes vegetation

removal, herbicide spraying, shaping of

banks to control erosion, and desilting

of the creek, all of which degrade

California red-legged frog habitat. In San

Luis Obispo and Santa Barbara counties,

maintenance work is planned for 14 and

11 drainages, respectively. All 25

drainages are known to be inhabited by

California red-legged frogs and represent

35 percent of the occupied drainages in

these two counties (U.S. Fish and

Wildlife Service 1995). In Santa Barbara

County, a larger channel maintenance

project is proposed for a 4.5-mile stretch

of the Santa Ynez River near Lompoc

and a 10-mile segment of San Antonio

Creek, both of which support California

red-legged frog habitat.

Management of water bodies for flood

control also has the potential to

adversely impact California red-legged
25826 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

frog localities. In San Mateo County,

poorly timed releases of storm water

from Horse Stable Pond at Sharp Park in

February 1992, resulted in exposure and

desiccation of 62 California red-legged

frog egg masses (Todd Steiner, Earth

Island Institute, in litt., 1994). Channel

maintenance at San Francisco

International Airport may have

contributed to extirpation of one of the

four largest remaining aggregations of

the California red-legged frog.

Routine road maintenance, trail

development, and facilities construction

activities associated with parks in or

adjacent to California red-legged frog

habitat can result in increased siltation

in the stream. If this siltation occurs

during the breeding season,

asphyxiation of eggs and small

California red-legged frog larvae can

result. On the upper Santa Ynez River

and Sespe Creek in Los Padres National

Forest, Sweet (pers. comm., 1993)

observed California red-legged frog egg

masses smothered with silt.

Construction activities in or adjacent to

streams at Butano and Portola State

Parks in San Mateo County; Big Basin,

Wilder Ranch, and Henry Cowell State

Parks in Santa Cruz County; and Mt.

Diablo State Park in Contra Costa

County have the potential to adversely

affect California red-legged frogs

inhabiting downstream reaches (Coyote

Creek Riparian Station, in litt., 1993).

Placer mining may threaten California

red-legged frog habitat. Jennings (pers.

comm., 1994) observed heavy siltation

in late spring and summer in portions

of Piru Creek known to support

California red-legged frogs. The siltation

resulted from upstream gold mining.

Deep holes in streams created by

instream placer mining also may

provide habitat for exotic predatory fish

(Jennings, pers. comm., 1994). Creeks,

streams and rivers are open to suction

dredging throughout the year in 13 of 22

counties within the current range of the

California red-legged frog (State of

California 1994).

Road-killed California red-legged

frogs have been documented at several

locations in San Mateo and Santa Cruz

Counties (Coyote Creek Riparian

Station, in litt., 1993; Mike Westphal,

Coyote Creek Riparian Station, in litt.,

1995). Road kills may deplete frog

aggregations in borderline habitat and

otherwise protected areas. Where roads

cross or lie adjacent to California redlegged frog habitat, they may act as

barriers to seasonal movement and

dispersal.

Livestock grazing is another form of

habitat alteration that is contributing to

declines in the California red-legged

frog. Numerous studies, summarized in

Behnke and Raleigh (1978) and

Kauffman and Krueger (1984), have

shown that livestock grazing negatively

affects riparian habitat. Cattle have an

adverse affect on riparian and other

wetland habitats because they tend to

concentrate in these areas, particularly

during the dry season (Marlow and

Pogacnik 1985). Cattle trample and eat

emergent and riparian vegetation, often

eliminating or severely reducing plant

cover (Gunderson 1968, Duff 1979). Loss

of riparian vegetation results in

increased water temperatures (Van

Velson 1979), which encourage bullfrog

reproduction. Riparian vegetation loss

due to cattle grazing includes the loss of

willows (Duff 1979), which are

associated with the highest densities of

California red-legged frogs (Hayes and

Jennings 1988, Jennings 1988b). Cattle

grazing also results in increased erosion

in the watershed (Lusby 1970, Winegar

1977), which accelerates the

sedimentation of deep pools (Gunderson

1968) used by California red-legged

frogs and adversely affects aquatic

invertebrates (Cordone and Kelley

1961). Aquatic invertebrates are

common prey items of California redlegged frogs.

Behnke and Zarn (1976) identified

livestock grazing as the greatest threat to

the integrity of stream habitat in the

western United States. Numerous

symposia and publications have

documented the detrimental effects of

livestock grazing on streams and

riparian habitats (Johnson and Jones

1977; Meehan and Platts 1978; Behnke

and Raleigh 1979; Bowers et al. 1979;

Cope 1979; Platts 1981; Ohmart and

Anderson 1982 and 1986; Peek and

Dalke 1982; Kauffman et al. 1983;

Menke 1983; Kauffman and Krueger

1984; Johnson et al. 1985; GAO 1988;

Clary and Webster 1989; Gresswell et al.

1989; Kinch 1989; Minshall et al. 1989;

Chaney et al. 1990 and 1993). These

effects include nutrient loading,

reduction of shade and cover with

resultant increases in water

temperature, increased intermittent

flows, changes in stream channel

morphology, and the addition of

sediment due to bank degradation and

off-site soil erosion. Indirect effects of

increased water temperatures can be

lethal to aquatic species and include:

creating a more favorable environment

for introduced species, changing the

food chain, degrading water quality

through decreased dissolved oxygen,

increased production of algae, and

increased pH and ammonia.

Various studies have shown that

water temperatures have been reduced

when streambank vegetative cover is

protected from grazing. Storch (1979)

found that daily fluctuations of water

temperatures in late August and early

September averaged 27° F outside an

exclosure on Camp Creek, Oregon that

was ungrazed for 10 years, compared to

13° F inside the exclosure. Also,

maximum water temperatures outside

the exclosure averaged 11° F higher than

inside the exclosure. Van Velson (1979)

reported that average water

temperatures in Otter Creek, Nebraska,

decreased 3° F after livestock were

excluded for 1 year.

Grazing effects are not limited to

riparian areas. Improper grazing of

upland vegetation can expose soils to

erosive impacts of rain drops, reduce

water infiltration, and accelerate runoff.

This can erode topsoil and cut rills and

gullies, concentrating runoff, deepening

gullies, lowering water tables, and

increasing sediment production (Chaney

et al. 1993). Sediment introduced into

streams can alter primary productivity

and food supply, fill interstitial spaces

in stream bed material, impeding water

flow, reducing dissolved oxygen levels,

and restricting waste removal (Chapman

1988). Suspended sediments reduce

light penetration to plants and reduce

oxygen carrying capacity of the water

(Ohmart and Anderson 1982).

Reduction in photosynthesis and

primary production decreases

productivity of the entire ecosystem

(Minshall et al. 1989).

Livestock grazing can cause a nutrient

loading problem (due to urination and

defecation) in areas where cattle are

concentrated near the water (Doran et al.

1981), but in other areas it can reduce

nutrients through removal of riparian

vegetation (Fisher 1972). Riparian

vegetation provides organic material for

approximately 50 percent of a stream’s

nutrient energy (Cummins 1974).

Detritus from such plants is a principal

source of food for aquatic invertebrates

(Minshall 1967; Meehan et al. 1977).

Streamside vegetation also provides

habitat for terrestrial insects, another

important dietary component for other

aquatic or riparian associated species.

Jennings et al. (1992) found livestock

grazing to occur at all known historic

locations of the California red-legged

frog in the Central Valley hydrographic

basin. Livestock grazing also has been

implicated as a contributing factor in

the decline and disappearance of

California red-legged frogs from the

lower Salinas River (L. Hunt, in litt.,

1993) and the San Francisco peninsula

(S. Barry, in litt., 1992). Two of the 14

remaining aggregations of California

red-legged frogs in the Central Valley

hydrographic basin (Corral Hollow

Ecological Reserve and Frank Raines

Regional Park) are threatened by
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25827

sedimentation of aquatic habitats either

directly or indirectly caused by

livestock grazing and off-road vehicle

use (Jennings et al. 1992). Galen

Rathbun (National Biological Service,

pers. comm., 1993) reports that grazing

is adversely altering California redlegged frog habitat on Pico, Van Gordon,

San Simeon, Santa Rosa, Cambria

Meadows, and Cayucos Creeks in San

Luis Obispo County. Grazing practices

can, however, be modified to minimize

impacts to California red-legged frogs.

Five-fold increases in California redlegged frog populations on Rancho San

Carlos in Monterey County may be

attributable in part to modifications of

grazing programs (J. Froke, in litt.,

1994).

In addition to cattle, feral pigs (Sus

scrofa) also disturb the riparian zone

through their rooting, wallowing and

foraging behavior in the shallow

margins of water bodies. Feral pigs

disturb and destroy vegetative cover,

trample plants and seedlings, and cause

erosion. At Pinnacles National

Monument, soil compaction and

possible disturbance of frog eggs caused

by feral pigs have been noted in

California red-legged frog habitat

(Stanley Albright, National Park Service,

in litt., 1994).

Off-road vehicle use adversely affects

California red-legged frogs in ways

similar to livestock grazing and feral pig

disturbance. Off-road vehicles damage

riparian vegetation, increase siltation in

pools, disturb the water in stream

channels and crush eggs, larvae,

juveniles, and adults. California redlegged frogs were eliminated in part by

off-road vehicle activities at the Mojave

River above Hesperia, at Rincon Station

on the west fork of the San Gabriel

River, and in Piru Creek above Pyramid

Lake (M. Jennings, pers. comm., 1993).

Heavy recreational use of parks (e.g.,

fishing, hiking, exploring) also can

degrade habitat for the California redlegged frog. At Big Basin Redwood Park

in Santa Cruz County, heavy

recreational use may have contributed

to the disappearance of California redlegged frogs from Opal Creek (Coyote

Creek Riparian Station, in litt., 1993).

Timber harvest threatens California

red-legged frogs through loss of riparian

vegetation and increased erosion in the

watershed, which fills pools with

sediment and smothers egg masses. In

Santa Cruz County, timber harvest is

proposed adjacent to Adams Creek

(Celia Scott, private citizen, pers.

comm., 1993), Whitehouse Creek (U.S.

Fish and Wildlife Service 1995) and

occurs periodically on a tributary of

Blooms Creek (Coyote Creek Riparian

Station, in litt., 1993). The proposed

timber harvests would occur in three of

18 streams in the County that support

California red-legged frogs. In Pescadero

Creek at Portola State Park (San Mateo

County), erosion and siltation caused by

severe winter storms and upstream

logging operations may have been the

cause of the disappearance of California

red-legged frogs from this portion of the

stream (Coyote Creek Riparian Station,

in litt., 1993).

B. Overutilization for commercial,

recreational, scientific, or educational

purposes. Records of harvesting

California red-legged frogs for human

consumption date back to an account by

Lockington (1879) of the commercial

harvest of this species for San Francisco

fish markets. From 1890 to 1900, the

California red-legged frog supported a

significant commercial harvest (Smith

1895) of about 80,000 frogs annually

(Jennings and Hayes 1984). Counties

surrounding San Francisco Bay

provided the bulk of the frog harvest in

the early to mid 1890s, with the

Sacramento and San Joaquin Valleys

increasing in importance by the end of

the decade (Chamberlain 1898, Jennings

and Hayes 1985). By 1900, harvest

figures for California red-legged frogs

fell dramatically, indicating that

overharvesting may have occurred.

Jennings and Hayes (1985) hypothesized

that this rapid decline in the California

red-legged frog population was the

result of selective harvesting of the

larger females. Introduction of the

bullfrog in California in 1896 was

probably in response to the dwindling

California red-legged frog population

(Jennings and Hayes 1985). Continued

harvesting of California red-legged frogs

for food by local individuals has been

reported for the Central Coast region

(Coyote Creek Riparian Station, in litt.,

1993). California red-legged frogs

reportedly taste better than bullfrogs, a

statement first made by Dickerson

(1906).

Prior to 1950, California red-legged

frogs were used sporadically for

research in high schools and

universities. At present, the California

red-legged frog is available

commercially from suppliers located

outside California in the pet trade.

Because the State of California prohibits

possession of wild California red-legged

frogs without a permit, frogs sold in the

pet trade presumably are reared in

captivity (M. Jennings, pers. comm.,

1993).

C. Disease or predation. There have

been no documented instances of

disease adversely affecting the

California red-legged frog.

Few data are available on the effect of

native predators on the California redlegged frog. Bitterns (Botaurus

lentiginosus) and black-crowned night

herons (Nycticorax nycticorax) are

likely predators of adult frogs (Jennings

and Hayes 1990). Juvenile California

red-legged frogs, which are more active

diurnally and less wary than adults,

may be more susceptible to predation by

diurnal predators, such as the great blue

heron (Ardea herodias) and several

species of garter snakes (Thamnophis

spp.) (Fitch 1940, Fox 1952), including

the endangered San Francisco garter

snake (Thamnophis sirtalis tetrataenia)

(Barry 1978, Wharton et al. 1986).

Recent postmetamorphs also may be

particularly vulnerable to predation by

garter snakes, as was found in other

species of ranid frogs by Arnold and

Wassersug (1978). Raccoons (Procyon

lotor), which are abundant in urban

settings, were the likely predator of

eight radio-tagged California red-legged

frogs in the riparian corridor of Pico and

San Simeon Creeks in San Luis Obispo

County (Rathbun, in litt., 1994). Other

possible, but undocumented

mammalian predators include striped

skunks (Mephitis mephitis), spotted

skunks (Spilogale putorius), and red fox

(Vulpes fulva). Larvae may be preyed

upon by aquatic beetles and damsel fly

naiads (Karl Malamud-Roam, Contra

Costa County Mosquito and Vector

Control District, in litt., 1994).

Introduced predators of particular

concern are the bullfrog, red swamp

crayfish (Procambarus clarkii), signal

crayfish (Pacifastacus leniusculus), and

several species of fish, including bass,

catfish (Ictalurus spp.), sunfish, and

mosquitofish (Moyle 1973; Hayes and

Jennings 1986, 1988). All species were

introduced into California in the late

1800s and early 1900s, and through

range expansions, reintroductions, and

transplants have become established

throughout most of the State (Riegel

1959, Bury and Luckenbach 1976,

Moyle 1976).

Several researchers in central

California have noted the decline and

eventual disappearance of California

red-legged frogs once bullfrogs become

established at the same site (L. Hunt, in

litt, 1993; S. Barry, in litt., 1992; S.

Sweet, in litt., 1993). Joseph DiDonato

(East Bay Regional Park District, pers.

comm., 1994) has observed the

disappearance of California red-legged

frogs from Pleasanton Ridge in Alameda

County within the last ten years. Today,

all former California red-legged frog

habitat on Pleasanton Ridge is occupied

by bullfrogs. Moyle (1973) attributed the

disappearance of California red-legged

frogs from the San Joaquin Valley and

Sierran foothill region primarily to a

combination of bullfrog predation and
25828 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

competition. All sites in the Sierra

Nevada foothills that supported

California red-legged frogs in the 1970s

now are inhabited by bullfrogs (M.

Jennings, in litt., 1993). Over the last

decade, Jennings (in litt., 1993) has

observed bullfrogs moving upstream

and/or downstream into formerly

pristine California red-legged frog

habitat in a number of drainages,

including streams in Ventura, Santa

Barbara, San Luis Obispo, Merced,

Stanislaus, and San Mateo counties.

Bullfrogs are introduced into drainages

by stocking of reservoirs and stock

ponds, dispersal and colonization,

conveyance of project water from other

streams inhabited by these exotics, and

releases by individuals. At The Nature

Conservancy’s Santa Rosa Plateau

Reserve in Riverside County (the only

site south of the Santa Clara River

drainage supporting California redlegged frogs), a docent found a school

teacher attempting to introduce bullfrog

tadpoles into the preserve in the 1980s

(M. Jennings, in litt., 1993). Additional

bullfrogs were removed from the

preserve in 1989 after apparent

introductions from a nearby frog

jumping contest (M. Jennings, in litt.,

1994). Once established, it is extremely

difficult to eliminate bullfrogs (M.

Jennings, in litt., 1993; Cecil Schwalbe,

National Park Service, Tuscon, Arizona,

pers. comm., 1993; Frank Slavens,

Woodland Park Zoological Gardens,

Seattle, Washington, pers. comm.,

1993). Over 60 percent of the streams or

drainages currently known to support

California red-legged frogs also are

inhabited by bullfrogs, either in

association with California red-legged

frogs or in other portions of the drainage

(U.S. Fish and Wildlife Service 1995).

Based on documented rates of local

extinction, the Service concludes that

eventually California red-legged frogs

will be locally extirpated from these 149

streams.

Bullfrogs prey on California redlegged frogs (S. Sweet, in litt., 1993),

other ranid frogs (Twedt 1993) and other

amphibians and aquatic reptiles

(Schwalbe and Rosen 1988). Twedt

(1993) documented four juvenile

northern red-legged frogs among the

contents of 22 adult bullfrog stomachs.

He also found a subadult bullfrog in one

of the adult bullfrog stomachs. This prey

item was between the size of an adult

male (approximately 80 mm (3.1 in.))

and adult female (approximately 85 mm

(3.3 in.)) red-legged frog, indicating that

bullfrogs could prey on subadult redlegged frogs. Stuart and Painter (1993)

found evidence of cannibalistic

behavior in bullfrogs. A stomach

content analysis revealed 87 percent of

total volume by weight was composed

of newly-metamorphosed and larval

Rana. Bullfrogs may have a competitive

advantage over California red-legged

frogs because of their (1) larger size, (2)

generalized food habits (Bury and

Whelan 1984), (3) extended breeding

season (Storer 1933), which allows for

production of two clutches of up to

20,000 eggs during a breeding season

(Emlen 1977), and (4) larvae being

unpalatable to predatory fish (Kruse and

Francis 1977). Bullfrogs also interfere

with red-legged frog reproduction.

Several researchers have noted male

red-legged frogs in amplexus with

(mounted on) both male and female

bullfrogs (Jennings and Hayes 1990;

Twedt 1993; M. Jennings, in litt., 1993;

Stebbins in litt., 1993). However, the

extent to which bullfrog predation,

competition, and reproductive

interference adversely affects red-legged

frogs has not been studied in the field

(Hayes and Jennings 1986). Habitat

alterations, including removal of

riparian or aquatic vegetation, reduced

stream flows, and sedimentation of

pools, often provide conditions

detrimental to red-legged frogs but

favorable to bullfrogs (Hayes and

Jennings 1986; Jennings 1988b;

Jennings, pers. comm., 1993).

Hayes and Jennings (1986, 1988)

found a negative correlation between

the abundance of introduced fish

species and California red-legged frogs.

These authors noted that aquatic sites

where introduced fishes were abundant

rarely had native ranids, and when

present, ranid populations were small.

A similar negative correlation was

reported by Hunt (in litt., 1993) for

California red-legged frogs in the Salinas

River drainage, by DiDonato (in litt.,

1994) on East Bay Regional Park District

properties in the San Francisco Bay

area, by Shaffer (in litt., 1994) for the

inner coast range, and by Moyle (1973)

for the foothill yellow-legged frog. These

references suggest that the observed

negative correlation between California

red-legged frogs and non-native fish is a

general principal. Of 32 streams

examined by Hayes and Jennings (1988),

introduced fishes were found in 44

percent.

Results of a recent study in artificial

ponds showed that mosquitofish and

bluegill (Lepomis macrochirus) were

significant predators of California redlegged frog larvae (Schmieder and

Nauman 1994). However, California redlegged frogs have been found in

association with mosquitofish in Corral

Hollow Creek (Alameda and San

Joaquin counties) (T. Strange, pers.

comm., 1994) and in three waterbodies

on East Bay Regional Park properties in

Contra Costa County (K. Swaim, in litt.,

1994). Malamud-Roam (in litt, 1994)

reported that mosquitofish occur in at

least four streams in Contra Costa

County known to support California

red-legged frogs. Mosquitofish also may

compete with California red-legged frogs

by consuming aquatic insects that are

potential food sources for

postmetamorphic frogs. Mosquitofish

have become established statewide and

are stocked routinely by mosquito

abatement districts as a mosquito

control measure (Moyle 1976).

D. The inadequacy of existing

regulatory mechanisms. Although the

California red-legged frog is classified as

a ‘‘Species of Special Concern’’ by the

State of California (Steinhart 1990) and

may not be taken without an approved

scientific collecting permit, this

designation provides no special, legally

mandated protection of the species and

its habitat. In 1972, the California Fish

and Game Commission amended its

sport fishing regulations to prohibit take

or possession of California red-legged

frogs (Bury and Stewart 1973). However,

because of the rarity of the California

red-legged frog and similarity to the

more common bullfrog, protection of

this taxon by State wardens and rangers

may be compromised (Coyote Creek

Riparian Station, in litt., 1993).

Section 1603 of the California Fish

and Game Code authorizes the

Department of Fish and Game (CDFG) to

regulate streambed alteration. The

Department must be notified and

approve any work that substantially

diverts, alters, or obstructs the natural

flow or substantially changes the bed,

channel or banks of any river, stream, or

lake. If an existing fish or wildlife

resource may be substantially adversely

affected by a project, CDFG must submit

proposals to protect the species within

30 days. However, if the Department

does not respond within 30 days of

notification, the applicant may proceed

with the work.

Section 404 of the Clean Water Act is

the primary Federal law that potentially

provides some protection for aquatic

habitats of the California red-legged

frog, if the habitats are determined by

the U.S. Army Corps of Engineers

(Corps) to be jurisdictional areas (i.e.,

waters of the United States). Under

section 404, nationwide permits, which

undergo minimal public and agency

review, can be issued for projects

involving less than 10 acres of wetlands

above the headwaters (i.e., streams with

less than five cubic feet per second (cfs)

mean annual flow) or for isolated

waters, unless a listed species may be

adversely affected. Many aggregations of
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25829

California red-legged frogs occur in

isolated wetlands and coastal streams

that may have mean annual flows less

than five cfs. Individual permits, which

are subject to more extensive review,

could be required for projects that have

more than minimal impacts to waters of

the United States. The Clean Water Act

does not afford any special protection

for candidate species. However, when

the California red-legged frog is listed,

the Corps will be required by section 7

of the Act to consult and obtain the

concurrence of the Service prior to the

authorization of any section 404 permit

affecting California red-legged frog

habitat.

Additionally and equally important,

the upland habitats adjacent to riparian

zones are not provided any protection

by Section 404 of the Clean Water Act.

Upland areas provide estivation and

dispersal habitats for this species.

Federal lands, including those of the

Forest Service, National Park Service,

Bureau of Land Management, Bureau of

Reclamation, and Department of

Defense, encompass approximately 10

percent of the current known range of

the California red-legged frog. Multiple

land use management, as currently

practiced by the Forest Service, Bureau

of Land Management, and National Park

Service, does not provide long-term

protection for the California red-legged

frog. State, County, and Regional Park

lands provide some protection from

some threats, however, these parks are

managed for multiple uses.

The National Environmental Policy

Act (NEPA) and California

Environmental Quality Act (CEQA)

require an intensive environmental

review of projects that may adversely

affect a Federally listed species.

However, project proponents are not

required to avoid impacts to non-listed

species, and proposed mitigation

measures are frequently not adequately

implemented. As with section 404

permits, the Service’s comments

through these environmental review

processes are only advisory. The Service

is aware of a proposed recreational

development in Santa Cruz County

undergoing environmental review that

is expected to extirpate an estimated 10

percent of the total remaining numbers

of the California red-legged frog

(Westphal in litt. 1995).

The California Coastal Act regulates

the approval of developments within

the costal zone. Although a significant

slowing in wetland losses has occurred,

the continued loss and degradation of

coastal wetlands since the California

Coastal Act was enacted in 1974 attests

to the limitations of this legislation.

E. Other natural or man-made factors

affecting its continued existence. Six

consecutive years of drought (1986–

1992) in California severely affected

remaining California red-legged frogs in

the Sierran foothills. Many sites in

intermittent streams that held California

red-legged frogs before the drought were

completely dry during field surveys

conducted between 1985 to 1992

(Jennings et al. 1992). Sites still holding

pools of water had water levels so low

that access by predators was enhanced.

Livestock grazing at many sites

exacerbated effects of the drought by

limiting or preventing riparian habitat

regeneration (Jennings et al. 1992).

Long-term survival of California redlegged frogs may be compromised by the

elimination of refuge areas during times

of the year when the stream is dry

(Rathbun, in litt., 1994). However,

California red-legged frog populations

are undoubtedly capable of recovering

from drought, provided other factors

have not irreparably degraded their

habitat, or California red-legged frogs

have not been completely extirpated

from the drainage.

Drought also may play a role in

decreased California red-legged frog

reproduction where frogs occur in

coastal lagoons. High salinities in the

Pescadero Marsh (San Mateo County)

have been attributed to drought

conditions in the watershed. At the

Pescadero Marsh Natural Preserve,

Jennings and Hayes (1990) found many

dead egg masses in a portion of the

marsh that were killed by excessive

(>4.5 parts per thousand) salinity levels.

Rathbun et al. (1991) speculated that the

absence of California red-legged frogs in

lower Santa Rosa Creek and lagoon in

San Luis Obispo County was due to

long-term drought exacerbated by

instream flow withdrawals. Since the

end of the drought California red-legged

frog numbers reportedly have increased

in lower Santa Rosa Creek (Rathbun in

litt. 1994; G. Schmitt, United Residential

Lot Owners of Cambria, Inc. in litt.

1994) probably as a result of increased

rainfall in the winter of 1992–1993.

Increased salinities were recorded in

several other coastal lagoons during the

drought years (C. Swift and K.

Worcester, pers. comm. in Jennings et

al. 1992). Increased salinity could also

result from periodic overtopping of the

beach bar during high tides or by storm

waves (D. Asquith, private consultant,

in litt. 1994). In 1993, Jennings (pers.

comm., 1993) reported the loss of

California red-legged frog egg masses

from increased salinity and unusual

flooding in Arroyo Laguna in San Luis

Obispo County. Because significant

numbers of California red-legged frogs

occur in coastal lagoons on the central

California coast, drought has the

potential to severely reduce production

of California red-legged frogs over a

significant portion of their remaining

range.

The overall effect of contaminants on

California red-legged frogs has not been

studied. Only one incident of California

red-legged frog mortality is known from

a diesel and gasoline spill in a tributary

of Blooms Creek (Santa Cruz County)

(Coyote Creek Riparian Station, in litt.,

1993).

Periodic wildfires may adversely

affect California red-legged frogs by

causing direct mortality, destroying

streamside vegetation, or eliminating

vegetation that protects the watershed.

The 1991 Lions Fire on upper Sespe

Creek in the Los Padres National Forest

destroyed known California red-legged

frog habitat (S. Sweet, pers. comm.,

1993). Following the fire, extensive

erosion in the watershed also negatively

affected California red-legged frogs and

their habitat (S. Sweet, pers. comm.,

1993).

Extensive flooding has been cited by

Jennings and Hayes (1994a) as a

significant contributing factor in the

extirpation of the California red-legged

frog from desert drainages of southern

California. For example, in the Mojave

River drainage, no verifiable records or

sightings exist of California red-legged

frogs after 1968 (Jennings and Hayes

1994a). The disappearance of this

species from the drainage coincided

with a catastrophic flood event in the

Mojave River in the winters of 1968 and

1969. Extensive flooding in other

portions of the California red-legged frog

range may have combined with other

factors to eliminate California redlegged frog aggregations (Richard

Seymour, Coyote Creek Riparian

Station, in litt., 1993; D. Martin, pers.

comm., 1994).

A considerable amount of occupied

California red-legged habitat exists in

the form of isolated patches along

stream courses. These patches of

suitable habitat represent mere

remnants of a much larger historical

habitat that once covered whole

drainages. Fragments of formerly

extensive populations of California redlegged frogs are now isolated from other

populations. Populations isolated in

habitat fragments are vulnerable to

extinction through random

environmental events or anthropogenic

catastrophes. With only three of 243

known creeks or drainages supporting

populations of over 350 adults, all

remaining occurrences are considered

vulnerable to these threats. Once a local
25830 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

extinction event occurs in an isolated

habitat fragment, the opportunity for

recolonization from a source population

is reduced. Thus, local extinctions via

stochastic processes, coupled with

habitat fragmentation may represent a

substantial threat to the continued

existence of the California red-legged

frog over much of its range.

The Service has carefully assessed the

best scientific and commercial data

available regarding the past, present,

and future threats faced by the

California red-legged frog in

determining to make this final decision.

Based on this evaluation, the preferred

action is to list the California red-legged

frog (Rana aurora draytonii) as

threatened. This taxon has been

extirpated from 70 percent of its former

range. Although California red-legged

frogs are now known to be found in

more locations within their present

range than previously thought, factors

adversely affecting the California redlegged frog are known to exist in 83

percent of the drainages supporting the

taxon (U.S. Fish and Wildlife Service

1995). These factors include but are not

limited to (1) urban encroachment, (2)

construction of large and small

reservoirs, water diversions and well

development, (3) flood control

maintenance, (4) road maintenance, (5)

placer mining, (6) livestock grazing and

feral pigs, (7) off-road vehicle use, and

(8) introduction or presence of exotic

predators and competitors. The

remaining 17 percent of occupied

drainages, the majority located in

Monterey, Santa Barbara, and San Luis

Obispo counties, currently are not

known to be subject to the above threats.

The California red-legged frog, therefore,

more appropriately fits the definition of

a threatened species. For the reasons

discussed below, critical habitat has not

been proposed.

Critical Habitat

Critical habitat is defined in section 3

of the Act as: (I) the specific areas

within the geographical area occupied

by a species, at the time it is listed in

accordance with the Act, on which are

found those physical or biological

features (I) essential to the conservation

of the species and (II) that may require

special management considerations or

protection; and (ii) specific areas

outside the geographical area occupied

by a species at the time it is listed, upon

a determination that such areas are

essential for the conservation of the

species. ‘‘Conservation’’ means the use

of all methods and procedures needed

to bring the species to the point at

which listing under the Act is no longer

necessary.

Section 4(a)(3) of the Act, as

amended, and implementing regulations

(50 CFR 424.12) require that, to the

maximum extent prudent and

determinable, the Secretary designate

critical habitat at the time a species is

determined to be endangered or

threatened. The Service finds that

designation of critical habitat is not

prudent for the California red-legged

frog at this time. Service 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 threat

to the species, or (2) such designation of

critical habitat would not be beneficial

to the species.

As discussed under Factor B in the

‘‘Summary of Factors Affecting the

Species’’ section, the California redlegged frog has been and continues to be

threatened by taking, an activity

difficult to control. Listing of the frog

may result in an increase in the threat

of vandalism, a concern expressed by

the petitioners and other experts (M.

Jennings, S. Sweet, pers. comm., 1993;

D. Martin, pers. comm., 1994).

California red-legged frogs occur in

isolated and fragmented wetland habitat

on private property and are at risk from

vandalism. Publication of specific

localities, which would be required in

proposing critical habitat, would reveal

precise locality data and thereby make

the species more vulnerable to acts of

vandalism, and increase the difficulties

of enforcement. Martin (pers. comm.,

1994) has observed acts of vandalism by

private landowners once they learned of

the presence of Yosemite toads (Bufo

canorus), on their property. The

Yosemite toad is a species of concern to

the Service (former category 2 species,

59 FR 58995).

In addition, a significant market exists

in California for frog meat, with

bullfrogs as the primary species sold. In

1993, the California Department of Fish

and Game arrested a number of

individuals involved in illegal

collection and sale of large numbers of

bullfrogs to San Francisco fish markets

(California Department of Fish and

Game 1993). To the untrained eye, the

California red-legged frog looks very

similar to a bullfrog and could be

accidentally taken for the market.

California red-legged frogs also could be

taken intentionally as they are reported

to be more palatable (Coyote Creek

Riparian Station, in litt., 1993; Jennings,

pers. comm., 1994). The California redlegged frog would be more vulnerable to

collection for market consumption if

precise locality data were published for

this species. Protection of California

red-legged frog habitat will be addressed

in the recovery process and through the

section 7 consultation process.

Therefore, due to the serious potential

for increased, unauthorized take, the

Service has determined that designation

of critical habitat for the California redlegged frog is not prudent.

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 practices. Recognition

through listing results in public

awareness and conservation actions by

Federal, State, and local agencies,

private organizations, and individuals.

The Act provides for possible land

acquisition and cooperation with the

States and requires that recovery actions

be carried out for all listed species. The

protection required of Federal agencies

and the prohibitions against taking and

harm 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 and with respect to its

critical habitat, if any is being

designated. Regulations implementing

this interagency cooperation provision

of the Act are codified at 50 CFR part

402. Section 7(a)(4) of the Act requires

Federal agencies to confer with the

Service on any action that is likely to

jeopardize the continued existence of a

species proposed for listing or result in

destruction or adverse modification of

proposed critical habitat. If a species is

listed subsequently, section 7(a)(2)

requires Federal agencies to ensure that

activities they authorize, fund, or carry

out are not likely to jeopardize the

continued existence of the species or

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.

Federal agencies that may be involved

as a result of this final rule are the

Bureau of Reclamation, Bureau of Land

Management, National Park Service,

Forest Service, and the Departments of

the Army, Navy and Air Force. At

several parks, the National Park Service

has conducted or is planning to conduct

status surveys for California red-legged

frogs (Daphne A. Hatch, National Park

Service, in litt., 1993; James Sleznick,

National Park Service, in litt., 1992;
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25831

Gary Fellers, National Park Service,

pers. comm., 1993). The Forest Service

has conducted and has ongoing

amphibian surveys in many National

Forests within the historic range of the

California red-legged frog (J.

Stephenson, pers. comm., 1993; D.

Martin, pers. comm., 1993; Maeton

Freel, U.S. Forest Service, pers. comm.,

1994). In Los Padres National Forest, the

Forest Service, in a cooperative effort

with other Federal and State agencies,

has altered flow regimes in Piru Creek

between Lake Pyramid Lake and Lake

Piru to benefit the endangered arroyo

southwestern toad. Although no specific

studies have been done, these flow

regime changes also may benefit the

California red-legged frog (Frederick

Gientke, United Water Conservation

District, in litt., 1994). The Forest

Service has also designated more than

31 miles of Sespe Creek in Los Padres

National Forest as ‘‘Wild and Scenic’’

under the National Wild and Scenic

Rivers Act of 1968.

The Contra Costa Water District is

constructing a large reservoir

construction project (Los Vaqueros

Reservoir) on Kellogg Creek, Contra

Costa County (Contra Costa Water

District 1993). The Bureau of

Reclamation’s role in this project is to

amend water service contracts and

modify water rights to facilitate project

construction (Penny Howard, U.S.

Bureau of Reclamation, in litt., 1994). A

mitigation and monitoring program is

proposed to compensate for California

red-legged frog habitat losses at Los

Vaqueros. The mitigation plan includes

a bullfrog and exotic fish control

program to be carried out for the life of

the reservoir project (Contra Costa Water

District 1993). The potential for success

of the mitigation plan is unknown. In

addition, Bureau of Reclamation

projects, including small loan projects

in Monterey County, the Cachuma

project in Santa Barbara County, the San

Felipe project in San Benito and Santa

Clara counties, and the Solano project in

Solano County, involve water contract

renewals as well as road maintenance

activities and grazing leases, all of

which may affect California red-legged

frogs. The U.S. Army Corps of Engineers

would be involved in many of these

projects through their permitting

authority under section 404 of the Clean

Water Act.

Any of the above mentioned Federal

agencies would be required to consult

with the Service if any action they fund,

authorize, or carry out may affect the

California red-legged frog. To the extent

that their habitats overlap in lagoon

areas, efforts made to conserve and

recover the tidewater goby

(Eucyclogobius newberryi), a Federally

listed endangered species, may also

help to conserve and recover the

California red-legged frog.

The Service is currently involved in

the development of two Habitat

Conservation Plans (HCP’s) that could

potentially protect three localities of

California red-legged frogs. The Kern

County Valley Floor HCP will protect a

minimum of 75 percent of the existing

California red-legged frog habitat in the

Bitterwater Creek drainage. The San

Joaquin County multispecies HCP may

also protect two localities, Corral

Hollow Creek and Lone Tree Creek.

Although the development of these

HCP’s will not preclude the need to list

the California red-legged frog, these

plans, if implemented, will protect

habitat for the taxon.

The Ventura Field Office is assisting

with the Santa Clara River Enhancement

and Management Plan, which is

progressing but is not finalized at this

time. A similar plan for Rancho San

Carlos (in the Carmel River drainage) is

also underway. Early planning efforts

are beginning for the Ventura and Santa

Ynez rivers. None of these planning

efforts preclude the need to list the

species, but will provide future

protection of habitat for the species.

One known California red-legged frog

locality in Riverside County and any

newly discovered localities in the

historic range of the species could be

protected by ongoing ecosystem-based

planning efforts in southern California.

In 1991, the State of California

established the Natural Communities

Conservation Planning (NCCP) Program

to address conservation needs of natural

ecosystems throughout the State. The

initial focus of the program is the

coastal sage scrub community in

southern California, however, riparian

habitats will also be addressed. Several

regional plans, including the Multispecies Conservation Plan (MSCP) and

the Multi-habitat Conservation Plan

(MHCP) of San Diego County, the

Southern and Central Coastal

Subregional NCCP/Habitat Conservation

Plans (Southern/Central/Coastal NCCP)

of Orange County, and the Riverside

County Stephens Kangaroo rat HCP and

San Bernardino County MSCP are under

development by a consortium of county

and municipal governments and other

parties, including the California

Department of Fish and Game and the

Service. Though no plans have been

completed to date, protection could be

provided if the California red-legged

frog occurs in any of the planning areas.

The one known extant population

occurs on the Santa Rosa Plateau

Reserve managed by The Nature

Conservancy.

The Service establishes the following

recovery units within the historical

range of the California red-legged frog:

(1) The western foothills and Sierran

foothills to 5,000 feet in elevation in the

Central Valley Hydrographic Basin; (2)

the central coast ranges from San Mateo

and Santa Clara counties south to

Ventura and Los Angeles counties; (3)

the San Francisco Bay/Suisun Bay

hydrologic basin; (4) southern

California, south of the Tehachapi

Mountains; and (5) the northern coast

range in Marin and Sonoma counties.

These five units are essential to the

survival and recovery of the California

red-legged frog. Designation of recovery

units assists the Service and other

agencies in identifying priority areas for

conservation planning under the

consultation (section 7) and recovery

(section 4) programs.

The Act and implementing

regulations found at 50 CFR 17.32 set

forth a series of general prohibitions and

exceptions that apply to all threatened

wildlife not covered by a special rule.

With respect to the California red-legged

frog, 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 conduct), 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

listed species. It also is illegal to

possess, sell, deliver, carry, transport, or

ship any such wildlife that has been

taken illegally. Certain exceptions apply

to agents of the Service and State

conservation agencies.

Permits may be issued to carry out

otherwise prohibited activities

involving threatened wildlife species

under certain circumstances.

Regulations governing permits are at 50

CFR 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.

It is the policy of the Service,

published in the Federal Register on

July 1, 1994 (59 FR 34272), to identify

to the maximum extent practicable at

the time a species is listed those

activities that would or would not

constitute a violation of section 9 of the

Act. The intent of this policy is to

increase public awareness of the effect

of this listing on proposed and ongoing

activities within the species’ range. The

Service believes that, based on the best

available information, the following
25832 Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations

actions will not result in a violation of

section 9:

(1) Road-kills or injuries caused by

vehicles operated lawfully on

designated public roads;

(2) Light to moderate carefully

managed livestock grazing that prevents

or minimizes the excessive trampling of

riparian and wetland habitat;

(3) Possession of legally acquired

California red-legged frogs;

(4) Unintentional hooking of a frog or

tadpole during otherwise lawful

engagement in fishing, and;

(5) Federally approved projects that

involve activities such as, discharge of

fill material, draining, ditching, tiling,

pond construction stream

channelization or diversion, or

alteration of surface or ground water

into or out of a wetland (i.e., due to

roads, impoundments, discharge pipes,

storm water detention basins, etc.),

when such activity is conducted in

accordance with any reasonable and

prudent measures given by the Service

in accordance with section 7 of the Act.

Activities that the Service believes

could potentially harm the California

red-legged frog and result in ‘‘take’’,

include, but are not limited to:

(1) Unauthorized collecting or

handling of the species;

(2) Introduction of exotic species such

as fish or other species of frogs directly

into, or within dispersal distance of,

known California red-legged frog

habitat;

(3) Unauthorized destruction/

alteration of the species’ habitat such as

discharge of fill material, draining,

ditching, tiling, pond construction,

diversion or alteration of stream

channels or surface or ground water

flow into or out of a wetland (i.e., due

to roads, impoundments, discharge

pipes, storm water detention basins,

etc.), operation of any vehicles within

the stream channel;

(4) Violation of discharge permits;

(5) Burning, cutting or mowing of

wetland or riparian vegetation, if

conducted in an untimely or

inappropriate manner (e.g., when

California red-legged frogs would be

killed or injured, or their occupied

habitat would be degraded or rendered

unsuitable);

(6) Pesticide applications in violation

of label restrictions;

(7) Discharges or dumping of toxic

chemicals, silt, or other pollutants (i.e.,

sewage, oil and gasoline) into waters, or

riparian and upland habitats supporting

the species;

(8) Interstate and foreign commerce

(commerce across State lines and

international boundaries) and import/

export (as discussed earlier in this

section) without prior obtainment of an

endangered species permit. Permits to

conduct these activities are available for

purposes of scientific research and

enhancement of propagation or survival

of the species.

Questions regarding whether specific

activities will constitute a violation of

section 9 should be directed to the Field

Supervisor of the Service’s Sacramento

Field Office (see ADDRESSES section).

Requests for copies of the regulations

concerning listed plants and general

inquiries regarding prohibitions and

permits may be addressed to the U.S.

Fish and Wildlife Service, Ecological

Services, Endangered Species Permits,

911 N.E. 11th Avenue, Portland,

Oregon, 97232–4181 (telephone 503/

231–2063; facsimile 503/231–6243).

National Environmental Policy Act

The Fish and Wildlife Service has

determined that Environmental

Assessments and Environmental Impact

Statements, 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 Cited

A complete list of all references cited

herein is available upon request from

the Field Supervisor, Sacramento Field

Office (see ADDRESSES section).

Author

The primary authors of this final rule

are Karen J. Miller, Alison Willy, Sheila

Larsen, and Steven Morey, Sacramento

Field Office (see ADDRESSES section),

telephone 916/978–4866.

List of Subjects in 50 CFR Part 17

Endangered and threatened species,

Exports, Imports, Reporting and

recordkeeping requirements, and

Transportation.

Proposed Regulation 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, 10080 Stat. 3500, unless otherwise

noted.

2. Section 17.11(h) is amended by

adding the following, in alphabetical

order under AMPHIBIANS, to the List of

Endangered and Threatened Wildlife to

read as follows:

§ 17.11 Endangered and threatened

wildlife.

* * * * *

(h) * * *

Species Historic

range

Vertebrate population where endangered

or threatened Status Whenlisted

Critical

habitat

Special

rules Common name Scientific name

AMPHIBIANS

* * * * * * *

Frog, California redlegged.

Rana aurora draytonii U.S.A.

(CA).

Entire (excluding Del Norte, Humboldt,

Trinity, & Mendocino Cos., CA; Glenn,

Lake, & Sonoma Cos., CA, west of the

Central Valley Hydrologic Basin;

Sonoma & Marin Cos., CA, west & north

of San Francisco Bay drainages and

Walker Creek drainage; and NV).

T NA NA

* * * * * * *
Federal Register / Vol. 61, No. 101 / Thursday, May 23, 1996 / Rules and Regulations 25833

Dated: May 17, 1996

Mollie H. Beattie,

Director, Fish and Wildlife Service.

[FR Doc. 96–12901 Filed 5–22–96; 8:45 am]

BILLING CODE 4310–55–P

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric

Administration

50 CFR Part 641

[Docket No. 951221305–6038–02; I.D.

020296B]

Reef Fish Fishery of the Gulf of

Mexico; Correction

AGENCY: National Marine Fisheries

Service (NMFS), National Oceanic and

Atmospheric Administration (NOAA),

Commerce.

ACTION: Correction to emergency interim

rule.

SUMMARY: This document corrects the

delay of effective date in an emergency

interim rule published on February 29,

1996 (61 FR 7751). The emergency

interim rule delayed indefinitely the

effective date for implementation of the

red snapper Individual Transferable

Quota (ITQ) system for the Gulf of

Mexico, previously scheduled to begin

April 1, 1996.

EFFECTIVE DATE: The delay of effective

date published February 29, 1996 (61 FR

7751) for amendments originally

published on November 29, 1995 (60 FR

61202) is corrected as of February 23,

1996, to extend through May 29, 1996.

FOR FURTHER INFORMATION CONTACT:

Robert A, Sadler, Fishery Management

Specialist, Southeast Regional Office,

813–570–5305.

SUPPLEMENTARY INFORMATION:

Background

In issuing an emergency interim rule

on February 29, 1996, NMFS

inadvertently indicated that the

scheduled April 1, 1996, effective date

for the Gulf of Mexico red snapper ITQ

system, implemented under FMP

Amendment 8 (60 FR 61200, November

29, 1995), would be delayed

indefinitely. Because an emergency

interim rule issued under section 305(c)

of the Magnuson Fishery Conservation

and Management Act can amend a

fishery management plan or plan

amendment and its implementing rule

only for the emergency period (limited

to 90 days), the indefinite delay was in

error.

Need for Correction

Accordingly, this action corrects the

emergency interim rule to specify the

correct ending date for the delay in the

effective date for the final rule

implementing the ITQ system. As

published, the effective date section and

amendatory instruction 2 are incorrect

and need to be changed.

Correction of Publication

The publication on February 29, 1995,

of the emergency interim rule (I.D.

020296B), which was the subject of FR

DOC. 96–4432, is corrected as follows:

On page 7751, in the third column,

under the preamble caption EFFECTIVE

DATES, in the last paragraph, the phrase

‘‘are delayed indefinitely.’’ is corrected

to read ‘‘is delayed through May 29,

1996.’’

On page 7753, in the third column, on

the last line of the introductory text of

the amendatory instruction 2, the word

‘‘indefinitely’’ is corrected to read

‘‘through May 29, 1996.’’

Dated: May 15, 1996.

Richard H. Schaefer,

Acting, Assistant Administrator for Fisheries,

National Marine Fisheries Service.

[FR Doc. 96–12786 Filed 5–22–96; 8:45 am]

BILLING CODE 3510–22–F