Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for the Alameda Whipsnake, 60608-60656 [05-20145]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 70, Number 200 (Tuesday, October 18, 2005)]
[Proposed Rules]
[Pages 60608-60656]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-20145]



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Part II





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Proposed Designation of 
Critical Habitat for the Alameda Whipsnake; Proposed Rule

Federal Register / Vol. 70, No. 200 / Tuesday, October 18, 2005 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AT93


Endangered and Threatened Wildlife and Plants; Proposed 
Designation of Critical Habitat for the Alameda Whipsnake

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
designate critical habitat for the Alameda whipsnake (Masticophis 
lateralis euryxanthus) pursuant to the Endangered Species Act of 1973, 
as amended (Act). In total, approximately 203,342 acres (ac) (82,289 
hectares (ha)) fall within the boundaries of the proposed critical 
habitat designation. The proposed critical habitat is located in Contra 
Costa, Alameda, San Joaquin, and Santa Clara counties, California.

DATES: We will accept comments from all interested parties until 
December 19, 2005. We must receive requests for public hearings, in 
writing, at the address shown in the ADDRESSES section by December 2, 
2005.

ADDRESSES: If you wish to comment, you may submit your comments and 
materials concerning this proposal by any one of several methods:
    1. You may submit written comments and information to Wayne White, 
Field Supervisor, U.S. Fish and Wildlife Service, Sacramento Fish and 
Wildlife Office, 2800 Cottage Way, Room 2605, Sacramento, California 
95825-1846.
    2. You may hand-deliver written comments to our Sacramento Fish and 
Wildlife Office, at the above address.
    3. You may send comments by electronic mail (e-mail) to alameda_
whipsnake@fws.gov. Please see the Public Comments Solicited section 
below for file format and other information about electronic filing.
    4. You may fax your comments to Wayne White, Field Supervisor, 
Sacramento Fish and Wildlife Office at (916) 414-6712.
    Comments and materials received, as well as supporting 
documentation used in the preparation of this proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at the Sacramento Fish and Wildlife Office, 2800 Cottage Way, 
Room 2605, Sacramento, California 95825-1846 (telephone (916) 414-
6600).

FOR FURTHER INFORMATION CONTACT: Arnold Roessler, Listing Branch Chief, 
Sacramento Fish and Wildlife Office, at the address or telephone number 
above.

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, comments or 
suggestions from the public, other concerned governmental agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) The reasons any habitat should or should not be determined to 
be critical habitat as provided by section 4 of the Act, including 
whether the benefit of designation will outweigh any threats to the 
subspecies due to designation;
    (2) Specific information on the amount and distribution of Alameda 
whipsnake habitat and occurrence records, and what habitat features are 
essential to the conservation of the subspecies and why;
    (3) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat;
    (4) Information regarding the benefits of excluding specific lands 
from, or including specific lands in, the designation of critical 
habitat including but not limited to, State lands contained within the 
Mount Diablo State Park in Contra Costa County; Department of Energy 
lands in Alameda and San Joaquin Counties; and Bureau of Land 
Management lands within Contra Costa County, including specific 
information about existing management plans in place for these lands, 
and the provisions of such plans for the conservation of the Alameda 
whipsnake and its habitat;
    (5) Any foreseeable economic, national security, or other potential 
impacts resulting from the proposed and/or final designation of 
critical habitat and, in particular, any impacts on small entities; and
    (6) Whether our approach to designating critical habitat could be 
improved or modified in any way to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concerns and comments.
    If you wish to comment, you may submit your comments and materials 
concerning this proposal by any one of several methods (see ADDRESSES 
section). Please submit Internet comments to alameda_whipsnake@fws.gov 
in ASCII file format and avoid the use of special characters or any 
form of encryption. Please also include ``Attn: Alameda whipsnake'' in 
your e-mail subject header and your name and return address in the body 
of your message. If you do not receive a confirmation from the system 
that we have received your Internet message, contact us directly by 
calling our Sacramento Fish and Wildlife Office at (916) 414-6600. 
Please note that the Internet address (alameda_whipsnake@fws.gov) will 
be closed out at the termination of the public comment period.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours. Individual respondents may request that we withhold 
their home addresses from the rulemaking record, which we will honor to 
the extent allowable by law. There also may be circumstances in which 
we would withhold from the rulemaking record a respondent's identity, 
as allowable by law. If you wish us to withhold your name and/or 
address, you must state this prominently at the beginning of your 
comment. However, we will not consider anonymous comments. We will make 
all submissions from organizations or businesses, and from individuals 
identifying themselves as representatives or officials of organizations 
or businesses, available for public inspection in their entirety. 
Comments and materials received will be available for public 
inspection, by appointment, during normal business hours at the 
Sacramento Fish and Wildlife Office (see ADDRESSES).

Designation of Critical Habitat Provides Little Additional Protection 
to Species

    In 30 years of implementing the Act, the Service has found that the 
designation of statutory critical habitat provides little additional 
protection to most listed species, while consuming significant amounts 
of available conservation resources. The Service's present system for 
designating critical habitat has evolved since its original statutory 
prescription into a process that provides little real conservation 
benefit, is driven by litigation and the courts rather than biology, 
limits our ability to fully evaluate the science involved, consumes 
enormous agency resources, and imposes huge social and economic costs). 
The Service believes that additional agency discretion would allow our 
focus to return to those actions that provide the greatest benefit to 
the species most in need of protection.

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Role of Critical Habitat in Actual Practice of Administering and 
Implementing the Act

    While attention to and protection of habitat is paramount to 
successful conservation actions, we have consistently found that, in 
most circumstances, the designation of critical habitat is of little 
additional value for most listed species, yet it consumes large amounts 
of conservation resources. Sidle (1987) stated, ``Because the Act can 
protect species with and without critical habitat designation, critical 
habitat designation may be redundant to the other consultation 
requirements of section 7.'' Currently, only 466 species or 37 percent 
of the 1,268 listed species in the United States under the jurisdiction 
of the Service have designated critical habitat.
    We address the habitat needs of all 1,268 listed species through 
conservation mechanisms such as listing, section 7 consultations, the 
section 4 recovery planning process, the section 9 protective 
prohibitions of unauthorized take, section 6 funding to the States, and 
the section 10 incidental take permit process. The Service believes 
that it is these measures that may make the difference between 
extinction and survival for many species.
    We note, however, that two courts found our definition of adverse 
modification to be invalid (March 15, 2001, decision of the United 
States Court Appeals for the Fifth Circuit, Sierra Club v. U.S. Fish 
and Wildlife Service et al., F.3d 434 and the August 6, 2004, Ninth 
Circuit judicial opinion, Gifford Pinchot Task Force v. United State 
Fish and Wildlife Service). In response to these decisions, we are 
reviewing the regulatory definition of adverse modification in relation 
to the conservation of the species.

Procedural and Resource Difficulties in Designating Critical Habitat

    We have been inundated with lawsuits for our failure to designate 
critical habitat, and we face a growing number of lawsuits challenging 
critical habitat determinations once they are made. These lawsuits have 
subjected the Service to an ever-increasing series of court orders and 
court-approved settlement agreements, compliance with which now 
consumes nearly the entire listing program budget. This leaves the 
Service with little ability to prioritize its activities to direct 
scarce listing resources to the listing program actions with the most 
biologically urgent species conservation needs.
    The consequence of the critical habitat litigation activity is that 
limited listing funds are used to defend active lawsuits, to respond to 
Notices of Intent to sue relative to critical habitat, and to comply 
with the growing number of adverse court orders. As a result, listing 
petition responses, the Service's own proposals to list critically 
imperiled species, and final listing determinations on existing 
proposals are all significantly delayed.
    The accelerated schedules of court ordered designations have left 
the Service with almost no ability to provide for adequate public 
participation or to ensure a defect-free rulemaking process before 
making decisions on listing and critical habitat proposals due to the 
risks associated with noncompliance with judicially-imposed deadlines. 
This in turn fosters a second round of litigation in which those who 
fear adverse impacts from critical habitat designations challenge those 
designations. The cycle of litigation appears endless, is very 
expensive, and in the final analysis provides relatively little 
additional protection to listed species.
    The costs resulting from the designation include legal costs, the 
cost of preparation and publication of the designation, the analysis of 
the economic effects and the cost of requesting and responding to 
public comment, and in some cases the costs of compliance with the 
National Environmental Policy Act (NEPA) (42 U.S.C. 4321-4347). None of 
these costs result in any benefit to the species that is not already 
afforded by the protections of the Act enumerated earlier, and they 
directly reduce the funds available for direct and tangible 
conservation actions.

Background

Subspecies Description

    The Alameda whipsnake is a member of the family Colubridae 
(Stebbins 1985), and one of two subspecies of Masticophis lateralis. 
The Alameda whipsnake is a slender, fast-moving, diurnally active snake 
with a slender neck, broad head, and large eyes. Alameda whipsnakes 
range from 3 to 4 feet (ft) (91 to 122 centimeters (cm)) in length. The 
Alameda whipsnake is distinguished from the more common chaparral 
whipsnake (Masticophis lateralis lateralis) by a sooty black back area, 
wider yellow-orange stripes that run laterally down each side, the lack 
of a dark line across the scale near the tip of the nose, an 
uninterrupted light stripe between the tip of the nose and eye, and the 
virtual absence of spotting on the underside of the head and neck. For 
more information on the Alameda whipsnake, refer to the final listing 
rule and previous final critical habitat designation published in the 
Federal Register on December 5, 1997 (62 FR 64306), and October 3, 2000 
(65 FR 58933), respectively.

Life History

    Members of the genus Masticophis are slender, fast-moving, diurnal 
snakes with a broad head, large eyes, and slender neck. When hunting, 
these snakes commonly move with the head held high and occasionally 
move it from side to side, possibly to aid in depth perception. Prey is 
seized with great speed, pinioned under loops of the body, and engulfed 
without constriction. The Alameda whipsnake is a lizard-eating 
specialist, although its diet may include other prey (e.g.), 
rattlesnakes and nesting birds) depending on an individual's size, sex, 
age, and location. These snakes are good climbers that can escape into 
scrub or trees. Additionally, they seek shelter in rock piles, 
outcrops, or small mammal burrows (Stebbins 1985).
    In a study of the thermal responses of the Alameda whipsnake, 
Hammerson (1979) observed that snakes emerged from burrows in the 
morning with a low body temperature, often exposing just the head 
first, then basking in full or partial sun until they reached a body 
temperature of 91.4 to 93.4 degrees Fahrenheit (33.0 to 34.1 degrees 
Celsius). Alameda whipsnakes maintained a high body temperature 
(compared to other snakes) during the day, and retreated to burrows 
when soil surface temperatures began to fall. Alameda whipsnakes have a 
higher degree of body temperature stability than other snakes (Swaim 
1994). Alameda whipsnakes maintain this high, stable body temperature 
by using open and partially open and or low growing shrub communities 
that provide cover from predators. Alameda whipsnakes require a mosaic 
of sunny and shady areas to regulate their body temperature.
    Swaim (1994) used trapping and radio telemetry to study several 
aspects of Alameda whipsnake life history at multiple sites in Alameda 
and Contra Costa counties. Adult snakes had a bimodal seasonal activity 
pattern with peaks during the spring mating season and a smaller peak 
during late summer and early fall. Although short, above-ground 
movements may occur during the winter, Alameda whipsnakes generally 
retreat in November into a hibernaculum (i.e.), a protective site where 
the snakes remain over the

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winter) and emerge in March. Courtship and mating were observed from 
late March through mid-June. During this time males move around 
throughout their home ranges, but females appear to remain at or near 
their hibernacula where mating occurs. The home range of a male Alameda 
whipsnake ranged from 4.7 to 21.5 ac (1.9 to 8.7 ha) in size (mean of 
13.6 ac (5.5 ha), n = 4), and showed a high degree of spatial overlap. 
Suspected egg-laying sites for two female snakes were located in 
grassland with scattered shrub habitat. Similarly, recent trapping 
studies have documented captures of spent females (i.e., 
morphologically identifiable as having recently laid eggs) within scrub 
communities (Swaim 2002a), suggesting that these areas are in close 
association with egg-laying sites. Typically, clutches of 6 to 11 eggs 
are laid between May and July (Stebbins 1985), with young hatching and 
emerging in late summer to early fall (Swaim 1994). These hatchlings 
have been seen and captured above ground from August through November. 
Prey items were occasionally detected in the stomachs of captured 
hatchlings during this period, indicating that some hatchlings feed 
prior to winter hibernation.
    Three individual snakes monitored by Swaim (1994) for nearly an 
entire activity season appeared to maintain stable home ranges. 
Movements of these individuals were multi-directional and individual 
snakes returned to specific areas and retreat sites after long 
intervals of nonuse. Snakes had one or more core areas (i.e., areas of 
concentrated use) within their home range as described above, with 
large areas of the home range receiving little use.

Geographical Range

    The Alameda whipsnake currently inhabits the inner coast range 
mostly in Contra Costa and Alameda counties (Jennings 1983; McGinnis 
1992; Swaim 1994), with additional occurrence records in San Joaquin 
and Santa Clara counties (CNDDB 2005; Swaim 2004). Compared to the much 
more common chaparral whipsnake, the Alameda whipsnake subspecies 
historic range has always had a very restricted distribution. The 
subspecies historic range most likely included the entirety of the 
coastal scrub and oak woodland communities throughout the East Bay in 
Contra Costa, Alameda, and parts of San Joaquin and Santa Clara 
counties (McGinnis 1992). The current distribution of the subspecies 
has been reduced from the known historic range to five separate areas 
with little or no interchange due to habitat loss, alteration, and 
fragmentation. The five populations remain centered in: (1) Sobrante 
Ridge, Tilden/Wildcat Regional Parks to the Briones Hills, in Contra 
Costa County (Tilden-Briones population); (2) Oakland Hills, Anthony 
Chabot area to Las Trampas Ridge, in Contra Costa County (Oakland-Las 
Trampas population); (3) Hayward Hills, Palomares area to Pleasanton 
Ridge, in Alameda County (Hayward-Pleasanton Ridge population); (4) 
Mount Diablo vicinity and the Black Hills, in Contra Costa County 
(Mount Diablo-Black Hills population); and (5) Wauhab Ridge, Del Valle 
area to the Cedar Mountain Ridge, in (Sunol-Cedar Mountain population). 
For more information on the current distribution of the subspecies, 
refer to the Federal Register notices listing the species on December 
5, 1997 (62 FR 64306) and the previous designation of critical habitat 
on October 3, 2000 (65 FR 58933).

Habitat

    The distribution of the Alameda whipsnake coincides most closely 
with scrublands broken by grassy patches, and rocky hillsides (Stebbins 
1985). Recent telemetry data indicate that, although home ranges of 
Alameda whipsnakes are centered on scrub plant communities, Alameda 
whipsnakes frequently venture out into adjacent habitats, including 
grassland, oak savannah, and occasionally oak-bay woodland. The Alameda 
whipsnake occurs typically within a mosaic of habitat types containing 
scrub/shrub (chamise-redshank chaparral, mixed chaparral, coastal 
scrub) communities, with a significant component of annual grassland, 
as well as other wooded habitats such as blue oak-foothill pine, blue 
oak woodland, coastal oak woodland, valley oak woodland, and riparian 
communities (Sawyer and Keeler-Wolf 1995; Mayer and Laudenslayer 1988; 
CDFG 1998) or rock outcrops. Alameda whipsnakes exhibit a preference 
for open-canopy stands and habitats with woody debris and exposed rock 
outcrops because these habitats provide areas for basking, cover from 
predators, and an ample source of prey. Until recently, Alameda 
whipsnakes were most often found on southeast, south, and southwest 
facing slopes (McGinnis 1992; Swaim 1994). Swaim (1994) reported that 
Alameda whipsnakes have been shown to travel distances greater than 500 
ft (152.5 meters (m)) over grassland and other vegetation types and 
communities to exposed rock outcrops.
    However, additional study has established that concentrated 
activity and/or movement occurs on all slope aspects, including 
northern exposures, riparian areas (e.g. stream corridors), and through 
both open and closed canopy woodlands (Swaim 2000; Swaim 2002b; Swaim 
2004; Swaim 2005b-d). Recent data from incidental sighting on free-
ranging Alameda whipsnakes and recapture trapping surveys show regular 
use of habitats a distance of greater than 656 ft (200 m) from scrub 
and chaparral and include observations of Alameda whipsnakes up to 
23,950 yards (yd) (7,300 m) from scrub (Swaim 2003; Swaim 2004; Swaim 
2005b), and movement of marked snakes of several thousand feet (meters) 
(Swaim 2005c) in a matter of 4 to 10 days.
    Telemetry data indicate that Alameda whipsnakes remain in 
grasslands for periods of several hours to weeks at a time (Swaim 
1994). Grassland habitats are extensively used by male Alameda 
whipsnakes during the spring mating season. Female Alameda whipsnakes 
use grassland areas after mating, possibly in search of egg-laying 
sites.
    Rock outcrops are considered an important feature of Alameda 
whipsnake habitat because they provide shelter and potential 
hibernacula. Rock outcrops also support lizard populations. Lizards, 
especially the western fence lizard (Sceloporus occcidentalis), are a 
major prey item of Alameda whipsnakes (Stebbins 1985; Swaim 1994). Most 
telemetered locations of Alameda whipsnakes were within rock outcrops 
and talus.

Threats

    Current threats to Alameda whipsnake habitat are urban development 
and associated impacts that result from increased human population 
densities, fire suppression and resulting likelihood of catastrophic 
wildfires, increased predation pressure, and incompatible grazing 
practices. McGinnis (1992) identified the loss of large blocks of prime 
habitat due to relatively recent urban development as the principle 
reason for the decline in the subspecies. The central and western 
portions of Alameda and Contra Costa counties are highly urbanized and 
continue to be subjected to increased urbanization. Habitat 
fragmentation from urban development and associated infrastructure 
(e.g., highway and road construction) has led to isolation of the five 
populations by wholly preventing or severely reducing movement of 
individuals between each of the areas occupied by the five populations. 
Consequently, these activities have reduced the total amount of habitat 
available for the Alameda whipsnake.

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Previous Federal Action

    On December 5, 1997, we published a final rule listing the Alameda 
whipsnake as threatened (62 FR 64306). On October 3, 2000, we published 
a final rule designating critical habitat for the Alameda whipsnake 
within Alameda, Contra Costa, San Joaquin, and Santa Clara counties (65 
FR 58933).
    On June 7, 2001, the Home Builders Association of Northern 
California and others filed a lawsuit in the Eastern District of 
California against the Service, challenging the final designation of 
critical habitat for the Alameda whipsnake (Home Builders Association 
of Northern California, et al. v. U.S. Fish and Wildlife Service, et 
al., CV F 01-5722 AWI SMS). On May 9, 2003, the U.S. District Judge 
vacated and remanded the October 3, 2000, final rule designating 
critical habitat for the Alameda whipsnake. On January 14, 2004, the 
Service was ordered to complete and publish a proposed rule on critical 
habitat designation for the Alameda whipsnake no later than October 1, 
2005, and to complete and publish a final rule no later than October 1, 
2006. For more information on previous Federal actions concerning the 
Alameda whipsnake, refer to the final listing rule published in the 
Federal Register (62 FR 64306).

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 that are necessary to bring an endangered or a threatened 
species to the point at which listing under the Act is no longer 
necessary.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against destruction or adverse modification of 
critical habitat with regard to actions carried out, funded, or 
authorized by a Federal agency. Section 7 requires consultation on 
Federal actions that are likely to result in the destruction or adverse 
modification of critical habitat. The designation of critical habitat 
does not affect land ownership or establish a refuge, wilderness, 
reserve, preserve, or other conservation area. Such designation does 
not allow government or public access to private lands.
    To be included in a critical habitat designation, the habitat 
within the area occupied by the species at the time of listing must 
first have features that are ``essential to the conservation of the 
species.'' Critical habitat designations identify, to the extent known 
using the best scientific data available, habitat areas that provide 
essential life cycle needs of the species (i.e., areas on which are 
found the primary constituent elements (PCEs), as defined at 50 CFR 
424.12(b)).
    Habitat occupied at the time of listing may be included in critical 
habitat only if the essential features thereon may require special 
management or protection. Thus, we do not include areas where existing 
management is sufficient to conserve the species. (As discussed below, 
such areas may also be excluded from critical habitat pursuant to 
section 4(b)(2) of the Act.) Accordingly, when the best available 
scientific data do not demonstrate that the conservation needs of the 
species so require, we will not designate critical habitat in areas 
outside the geographical area occupied by the species at the time of 
listing. An area currently occupied by the species but was not known to 
be occupied at the time of listing will likely be essential to the 
conservation of the species and, therefore, included in the critical 
habitat designation.
    The Service's Policy on Information Standards Under the Act, 
published in the Federal Register on July 1, 1994 (59 FR 34271), and 
Section 515 of the Treasury and General Government Appropriations Act 
for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658) and the associated 
Information Quality Guidelines issued by the Service, provide criteria, 
establish procedures, and provide guidance to ensure that decisions 
made by the Service represent the best scientific data available. They 
require Service biologists, to the extent consistent with the Act and 
with the use of the best scientific data available, to use primary and 
original sources of information as the basis for recommendations to 
designate critical habitat. When determining which areas are critical 
habitat, a primary source of information is generally the listing 
package for the species. Additional information sources include the 
recovery plan for the species, articles in peer-reviewed journals, 
conservation plans developed by States and counties, scientific status 
surveys and studies, biological assessments, or other unpublished 
materials and expert opinion or personal knowledge. All information is 
used in accordance with the provisions of Section 515 of the Treasury 
and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658) and the associated Information Quality Guidelines 
issued by the Service.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Habitat is often 
dynamic and may change over time due to vegetational succession, 
climate, or catastrophic events (e.g., fire, landslides). As a result 
of habitat change a species may move from one area to another over 
time. Furthermore, we recognize that designation of critical habitat 
may not include all of the habitat areas that may eventually be 
determined to be necessary for the recovery of the species. For these 
reasons, critical habitat designations do not signal that habitat 
outside the designation is unimportant or may not be required for 
recovery.
    Areas that support populations, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions implemented under section 7(a)(1) of the Act and to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available information 
at the time of the action. Federally funded or permitted projects 
affecting listed species outside their designated critical habitat 
areas may still result in jeopardy findings in some cases. Similarly, 
critical habitat designations made on the basis of the best available 
information at the time of designation will not control the direction 
and substance of future recovery plans, habitat conservation plans, or 
other species conservation planning efforts if new information 
available to these planning efforts calls for a different outcome.

Methods

    As required by section 4(b)(1)(A) of the Act, we use the best 
scientific data available in determining areas that contain the 
features that are essential to the conservation of the Alameda 
whipsnake, including information gathered for the Draft Recovery Plan, 
information from local subspecies experts, published and unpublished 
research papers (e.g., peer-reviewed journal articles in the public 
domain), academic theses, abstracts of presentations at scientific 
meetings, notes from our attendance at such presentations, consultation 
with recognized experts in the field, and review of case studies of 
other critical habitat designations. We assembled the

[[Page 60612]]

best and most recently available information on soil, vegetation, 
Alameda whipsnake records, topography, urban development, road systems, 
and aerial imagery, into a Geographic Information Systems (GIS) 
database. We are not proposing to designate any areas as critical 
habitat that lie outside the geographical area presently occupied by 
the subspecies.
    We have also reviewed available information that pertains to the 
habitat requirements of this subspecies, including reports submitted 
during section 7 consultations and by biologists holding section 
10(a)(1)(A) recovery permits; research published in peer-reviewed 
articles and presented in academic theses and agency reports; and 
regional GIS coverages.
    As mentioned in the Habitat and Primary Constituent Elements 
sections, Alameda whipsnakes have the capability and need for long 
range movement. These movements are essential for establishment of home 
ranges, finding retreats, maintenance of gene flow, recolonization of 
habitat, relocation in response to disturbance, and finding mates. Such 
movements have been documented by observation of snake distance from 
scrub habitat (Swaim 2003) and tracking of snake movements (Swaim 2005 
b-d), and are well within the general range as exemplified by other 
snake species in the same family (Loughheed et al. 1999; Blouin-Demers 
and Weatherhead 2002). Habitat determined to be occupied included that 
habitat between recorded observations within the capable and necessary 
range of movement, which has relatively high quality habitat for the 
Alameda whipsnake, PCEs, and other factors (see Criteria for 
Identification of Critical Habitat, below). Only such occupied habitat 
has been considered in the designation of critical habitat for this 
subspecies. All proposed units were occupied at the time of listing and 
are currently occupied by the Alameda whipsnake.
    A GIS database was constructed to overlay key layers which served 
as indices of habitat quality. The critical habitat boundary was 
adjusted as warranted by major landforms and features (e.g., 
ridgelines, water courses), soils, development, distance from known 
records, and barriers to movement.
    We determined that soil type could be employed to distinguish those 
areas most likely to support Alameda whipsnake and/or its PCEs. To 
determine suitability, soils were ranked by the number of Alameda 
whipsnake records falling within individual soil types. We decided to 
map those soil layers with a minimum of three Alameda whipsnake 
records. Because of the inherent biases in Alameda whipsnake data 
collection techniques, we believe this criterion does not over-
represent areas with a single observation, nor under-represent those 
areas that had numerous records as a consequence of more frequent 
scientific study. The soil types associated with three or more Alameda 
whipsnake records included rock outcrop, wisflat-arburua-san timoteo 
complex, various types of loams, rocky loams, clay loams, and silt 
loams, and riverwash. Although rock outcrops and rocky soils accounted 
for a disproportionate number of Alameda whipsnake observations, 
multiple Alameda whipsnake records were also associated with other soil 
types. Many of the same soils associated with multiple Alameda 
whipsnake records are also associated strongly with chaparral or 
coastal scrub. Thus, soil type associated with multiple Alameda 
whipsnake records was considered a useful indicator of the presence of 
appropriate vegetation and rocky land or talus.
    Vegetation quality was evaluated by examining the distribution and 
pattern of the grassland and woodland vegetation types used by Alameda 
whipsnake. Two primary sources were used: (1) The GIS-based land-cover 
map for California (California GAP Analysis 1998), and (2) visual 
inspection of digital aerial imagery from several sources. The visual 
inspection was necessary because the mapping unit for the GAP is 
relative large (i.e., 100 ha) and because of a somewhat restrictive GAP 
mapping criterion (designations reflect a dominant canopy species, 
i.e., greater than 20 percent). In some cases, vegetation very similar 
in appearance to chaparral could be seen in the aerials but was not 
reported as dominant in the GAP layer. Much smaller amounts of 
chaparral are likely to be distributed more widely, but could not be 
detected with either the GAP or aerial imagery layers. In general, 
habitat quality was deemed to be higher where all PCEs were present in 
abundance, and where the vegetation consisted of a more finely 
dissected mosaic. Additionally, areas which had chaparral were 
considered of greater importance because of the stronger association of 
snake records with this vegetation type. Quantitative limits for 
average patch dimension and/or minimum amount of chaparral were not 
established due to the varying size of chaparral known to support the 
Alameda whipsnake.
    We also examined the digital imagery for roads, structures, 
cultivation, or other disturbances that would affect habitat quality 
for Alameda whipsnake. Some areas were not included as critical habitat 
because the level of such disturbance was determined to be high to 
support the Alameda whipsnake over time.

Criteria Used To Identify Critical Habitat

    The criteria we utilized to designate critical habitat for Alameda 
whipsnake are based on the best scientific information available about 
the biology and ecology of the subspecies. In our determination of 
critical habitat for the Alameda whipsnake, we selected areas that 
possess the physical and biological features essential to the 
conservation of the subspecies and that may require special management 
considerations or protection. Application of these criteria (1) 
protects the best quality habitat in areas where Alameda whipsnake 
occurs; (2) maintains the current geographical, elevational, and 
ecological distribution of habitat and the subspecies, thereby 
preserving genetic variation within the range of the Alameda whipsnake, 
and minimizing the effects of local extinction; (3) minimizes 
fragmentation by establishing unit boundaries that would result in the 
lowest possible ratio of perimeter/unit area, maintaining the essential 
need for snake movement, dispersal, and interaction within the 
population. The specific habitat quality factors that we considered in 
determining critical habitat included soil type, vegetation type, 
vegetation mosaic, and degree of included development (e.g., roads, 
structures).
    There is no firm information on the actual population of Alameda 
whipsnake within its range. In addition, there has been no analysis of 
the minimum viable population size necessary to maintain a stable or 
increasing population of Alameda whipsnake. However, expert opinion is 
that the subspecies persists in relatively low numbers throughout its 
range (McGinnis 1992). Moreover, irretrievable loss of occupied Alameda 
whipsnake habitat due to recent urban development is significant in 
areas adjacent to several of the proposed critical habitat units. This 
development has likely resulted in a commensurate reduction in 
population size for the Alameda whipsnake. Accordingly, the general 
pattern of habitat loss and fragmentation was taken into consideration 
in the designation of critical habitat.
    Connectivity has been applied as a criterion to those areas where 
designation would result in a relatively high potential for dispersal 
between and within units. The need for special

[[Page 60613]]

management considerations was applied where such management may be 
essential to enhance the connectivity or the integrity of high quality 
habitat within a unit.
    We are proposing to designate critical habitat on lands that we 
have determined are occupied at the time of listing and that contain 
the features found to be essential to the conservation of the Alameda 
whipsnake (PCEs). Within the boundaries of critical habitat, land that 
contains developed areas such as buildings, paved areas, and other 
structures has been excluded from this designation.
    Section 10(a)(1)(B) of the Act authorizes us to issue permits for 
the take of listed species incidental to otherwise lawful activities. 
An incidental take permit application must be supported by a habitat 
conservation plan (HCP) that identifies conservation measures that the 
permittee agrees to implement for the species to minimize and mitigate 
the impacts of the requested incidental take. We often exclude non-
Federal public lands and private lands that are covered by an existing 
operative HCP and executed implementation agreement (IA) under section 
10(a)(1)(B) of the Act from designated critical habitat because the 
benefits of exclusion outweigh the benefits of inclusion as discussed 
in section 4(b)(2) of the Act. We are proposing to exclude critical 
habitat from portions of Unit 4 based on the development of the draft 
East Contra Costa County HCP and lands within the East Bay Regional 
Park District. See Relationship of Critical Habitat to the Draft East 
Contra Costa County Habitat Conservation Plan (ECCHCP) below.

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas to propose as critical 
habitat, we are required to base critical habitat determinations on the 
best scientific data available and to consider those physical and 
biological features (PCEs) that are essential to the conservation of 
the species, and that may require special management considerations and 
protection. These include, but are not limited to: space for individual 
and population growth and for normal behavior; food, water, air, light, 
minerals, or other nutritional or physiological requirements; cover or 
shelter; sites for breeding, reproduction, and rearing (or development) 
of offspring; and habitats that are protected from disturbance or are 
representative of the historic geographical and ecological 
distributions of a species. The specific PCEs essential for the 
conservation of the Alameda whipsnake are derived from the biological 
and ecological needs of the Alameda whipsnake as described in the 
Background section of this proposal and in previous listing and 
critical habitat rules for the species, as well as derived from the 
abiotic and biotic needs of the species as described below.
    The specific feeding and foraging habits of Alameda whipsnake are 
relatively well known (Stebbins 1985; Swaim 1994; Green 1998). Alameda 
whipsnake prey extensively on western fence lizards (Sceloporus 
occidentalis), but also have been known to prey on western skinks 
(Eumeces skiltonianus), as well as frogs, birds, and other snakes 
(Stebbins 1985; Swaim 1994). Its specialization on lizard prey and mode 
of foraging require areas that both support abundant prey populations 
and provide prey-viewing and capture opportunities. The Alameda 
whipsnake is most frequently recorded in close association with 
chaparral or scrub patches. These patches serve as the center of home 
ranges, and provide for concealment from predators and prey-viewing 
opportunities while foraging. Snakes venture into adjacent grasslands 
or wooded habitats that exhibit, at a minimum, a partially open canopy. 
The open canopy character is believed to allow both development of the 
primary lizard prey base used by the snake, and efficient 
thermoregulation and foraging activities. The Alameda whipsnake hunts 
by sight, holding its head off the ground to peer over grass or rocks 
for potential prey capture opportunities. Essential features of Alameda 
whipsnake habitat must therefore include consideration of the habitat 
needs of the prey species and for prey captures. Such opportunities, as 
well as the prey base, are provided for by what is termed a ``scrub 
community.'' The particular arrangement of the landscape mosaic that 
supports Alameda whipsnake commonly consists of scrub patches within an 
open canopy of interspersed grasslands and rocklands, but may include 
closed or nearly closed scrub areas, including rocklands, and a much 
lower complement of grasses. Typical scrub communities within the range 
of the Alameda whipsnake include diablan sage scrub, coyote bush scrub, 
and chamise chaparral (Swaim 1994), also classified as coastal scrub, 
mixed chaparral, and chamise-chaparral (Mayer and Laudenslayer 1998), 
and chamise, chamise-eastwood manzanita, chaparral whitethorn, and 
interior live oak shrub vegetation series as identified in the Manual 
of California Vegetation (Sawyer and Keeler-Wolf 1995), A Guide to 
Wildlife Habitats of California (Mayer and Laudenslayer 1988), and 
California Wildlife Habitat Relationship System (CDFG 1998). These 
vegetation series are characterized as being less than 20 ft (6 m) in 
height with sparse ground cover (the interior live oak shrub vegetation 
series having variable ground cover) and form a nearly continuous cover 
of closely spaced shrubs often with intertwining branches. Sufficient 
light penetrates through the canopy to support a herbaceous understory. 
The soils are usually nutrient poor and rocky, and stands are best 
developed on steep slopes. Because of complex patterns of topographic, 
edaphic, and climatic variations, these vegetation series form a mosaic 
pattern with inclusions of other vegetation series (blue oak, coast 
live oak, California Bay, California buckeye, California annual 
grassland) or open spaces. The percentage cover for these vegetation 
series is variable depending on species composition and aspect. Bare 
zones about 3 ft (1 m) wide may be interspersed within these vegetation 
series and extend around and out into adjacent vegetation series. These 
vegetation series occur on all slope aspects with patch sizes varying 
from square feet (meters) to square miles (kilometers) in dimension. 
The plant species associated with these vegetation series include, but 
are not limited to: chamise (Adenostoma sp.), manzanita (Artostaphylos 
sp.), Ceanothus sp., buckwheat (Eriogonum sp.), bush monkey flower 
(Diplacus sp.), toyon (Heteromeles arbutifolia), scrub oak (Quercus 
sp.), interior live oak (Q. wislizenii), canyon live oak (Q. 
chrysolepis), California coffeberry Rhamnus sp.), California buckeye 
(Aesculus californica), poison oak (Toxicodendron diversilobum), yerba 
santa (Eriodictyon californicum), and mountain mahogany (Cercocarpus 
sp.).
    Swaim (1994) found that core areas (i.e., areas of concentrated use 
by Alameda whipsnakes, based on telemetry and trapping data) were 
predominantly located on east, southeast, south, or southwest facing 
slopes and were characterized by open or partially-open canopy or 
grassland within 500 ft (150 m) of scrub. In early studies, Alameda 
whipsnakes were captured primarily where the canopy cover was open 
(less than 75 percent cover) or partially open (75 to 90 percent 
cover). However, more recent trapping efforts have collected Alameda 
whipsnakes in scrub ranging from nearly complete or completely closed 
canopies, to very open canopies with a

[[Page 60614]]

few patches of high quality scrub present (Swaim 2005b). These core 
areas provide sun-shade mosaics that offer an opportunity for the snake 
to achieve temperatures necessary for foraging, while providing retreat 
from predators (Swaim 1994). The open scrub habitat supports prey 
viewing opportunities, aiding foraging opportunities for this diurnal 
sight-hunting snake (Swaim 1994). As previously mentioned, capture of 
spent females within scrub communities (Swaim 2002a) indicates scrub 
areas are in very close association with egg-laying sites, probably 
located in nearby grassland. Because they provide the primary foraging, 
breeding, and shelter areas for Alameda whipsnake, scrub communities 
are considered a PCE essential to the conservation of this subspecies.
    Although much of Alameda whipsnake activity occurs in scrub 
communities, other types of vegetation are also used for foraging and 
are necessary for normal behavior, breeding, reproduction, population 
interaction, and dispersal. Core areas used by the snake can be 
sustained by very small patches of scrub embedded within a larger 
mosaic of other dominant vegetation types (Swaim 2005b). Our review of 
available vegetation data and aerial imagery indicate that much of the 
distribution of Alameda whipsnake does not consist of large unbroken 
tracts of scrub community. The vegetation types adjacent to the scrub 
habitat that the Alameda whipsnake needs for foraging, dispersal, and 
population interactions include annual grassland, blue oak-foothill 
pine, blue oak woodland, coastal oak woodland, valley oak woodland, 
eucalyptus, redwood, and riparian communities (e.g. stream corridors). 
McGinnis (1992) has documented Alameda whipsnakes using oak woodland/
grassland habitat as a corridor between stands of northern coastal 
scrub.
    Grassland habitats are used extensively by both sexes of Alameda 
whipsnake during the breeding season. Males used these areas most 
extensively during the spring mating season, possibly in search and 
selection of mates (Swaim 1994). Female use occurred after mating, 
possibly looking for egg laying sites or for dispersal to scrub habitat 
(Swaim 1994, Swaim 2002a). Specifically, concentrated activity of 
gravid females, and hence the suspected location of egg laying sites, 
was in grassland areas with scattered shrubs within 10 to 20 ft (3 to 6 
m) of true scrub habitat (Swaim 1994).
    Embedded within these scrub communities and adjacent habitats are 
areas consisting of rocky habitat (either rock outcrops or rock debris 
piles, known as ``talus'') and small rodent burrows; however, brush 
piles and deep soil crevices are also used by the snake (Swaim 1994). 
These areas are essential for normal behavior, breeding, reproduction, 
dispersal, and foraging because they provide shelter from predators, 
egg laying sites, over night retreats, and winter hibernacula (Swaim 
1994) and are associated with areas that have increased numbers of 
foraging opportunities (Stebbins 1985; Swaim 1994). Swaim (1994) found 
rock outcrops were typically abundant in core areas and observed 
Alameda whipsnakes mating in these outcrops. During the mating season 
females remain near the retreat sites while males disperse throughout 
their home ranges (Swaim 1994). Hammerson (1979 in litt.) observed 
Alameda whipsnake emerging from burrows in the morning, basking in the 
sun, and retreating into burrows when the soil surface temperatures 
began to fall. Alameda whipsnakes retreat into winter hibernacula (e.g. 
rodent burrows, crevices between rocks) around November and emerge in 
March. Trapping of gravid females close to scrub communities in 
grassland with scattered shrubs (Swaim 1994) and spent females in true 
scrub communities (Swaim 2002a) suggests that rock outcrops, talus, and 
burrows (mating habitats) need to be relatively close to scrub and 
nearby grassland habitat (suspected egg laying habitats).
    Dispersal habitats are essential for the conservation of Alameda 
whipsnake. Protecting the ability of Alameda whipsnake to move freely 
across the landscape in search of habitats is essential for: (1) 
Sustaining populations by providing opportunity for movement and 
establishment of home ranges by juvenile recruits, (2) maintaining gene 
flow by the movement of both juveniles and adults between 
subpopulations, and (3) allowing recolonization of habitat after fires 
or other natural events that have resulted in local extirpations. The 
available information on movements of other colubrid snakes is limited 
to a small minority of species, but indicates a general potential for 
significant mobility. Loughheed et al. (1999) found evidence of 
substantial genetic exchange among local hibernacula greater than 3.75 
miles (6 km) apart, although gene flow over distances of 6.25 miles (10 
km) and greater appears to be substantially less. Based on extensive 
radio-tracking data, Blouin-Demers and Weatherhead (2002) found that 
male and female ratsnake (Elaphe obsolete) (a species similar in size 
and characteristics to the Alameda whipsnake) travel up to 5 miles (8 
km) from hibernacula to mate. Therefore, it is likely that medium-sized 
species of this group, such as the Alameda whipsnake, move between 
areas up to a few miles apart. This is consistent with the distribution 
of vegetation types in portions of the Alameda whipsnake range, where 
the vegetation often has more dense closed canopy on the northeast-
facing slopes, and less dense open canopy on southwest-facing slopes. 
Very recent trapping data has shown several instances of snakes 
residing in and moving through predominantly north-facing slopes in two 
of the six proposed units (Swaim 2005c, Swaim 2005d). Habitat with a 
more open canopy would provide the greatest range of essential 
functions. However closed-canopy areas are considered essential because 
they provide avenues of dispersal and interaction between sub-
populations, and movement through such closed-canopy areas has been 
documented (Swaim 2002b).
    Additional trapping data has shown the maximum distance between 
Alameda whipsnake observations from the nearest scrub is much larger, 
up to 4.5 miles (7.3 km), than either the home range diameter or 
average movements, suggesting more extensive use of grassland for 
either foraging or corridor movement (Swaim 2000; Swaim 2003; Swaim 
2005b). The scale of these grassland patches is on the order of several 
miles (kilometers) across, and movement of this degree would permit 
Alameda whipsnakes to disperse to other adjacent habitat. Large blocks 
of contiguous habitat, relatively uninterrupted by roads, structures, 
or other development, fulfills the essential need for interchange and 
interaction among individuals and subpopulations within the limited 
distribution of Alameda whipsnake. Thus, other vegetation (e.g., annual 
grassland, blue oak-foothill pine, blue oak woodland, coastal oak 
woodland, valley oak woodland, eucalyptus, redwood, and riparian 
communities) adjacent to scrub habitat is considered a feature 
essential to the conservation of the Alameda whipsnake.
    The characteristics and composition of the vegetation series 
adjacent to scrub or rocky habitats which are used by Alameda whipsnake 
for foraging, short and long distant dispersal, and mating can be 
variable depending on location, topography, soils, and rainfall. The 
woodland vegetation series are comprised of slow growing, long-lived 
deciduous and evergreen trees 15 to 70 ft (4 to 21 m) tall with a mixed

[[Page 60615]]

understory of grass and herbaceous vegetation or shrub vegetation. Some 
common species associated with the woodland vegetation series include: 
blue oak (Quercus douglassi), valley oak (Quercus lobata), canyon live 
oak, California black oak (Quercus kellogi), interior live oak, madrone 
(Arbutus menziesii), foothill pine (Pinus sabatiana), California bay, 
California buckeye, coyote brush, manzanita, gooseberry (Ribes sp.), 
redwood (Sequoia sempervirens), and Eucalyptus sp. Some common species 
associated with the California annual grassland vegetation series 
include: wild oats (Avena sp.), soft chess (Bromus mollis), brome sp., 
barley (Hordeum sp.), and fescue (Festuca sp.). Some remnant perennial 
grasses may also be distributed within this grassland vegetation series 
comprised of species such as needlegrass (Nassella sp.), California 
onion grass (Melica californica), and California fescue (Festuca 
californica). Herbaceous vegetation within the woodland and grassland 
vegetation series includes filaree sp., turkey mullein (Eremocarpus 
sp.), popcorn flower (Plagiobothrys sp.), and California poppy 
(Eschscholtzia california).

Primary Constituent Elements for the Alameda Whipsnake

    Based on our current knowledge of the life history, biology, and 
ecology of the Alameda whipsnake and the requirements of the habitat 
necessary to sustain the essential life history functions of the 
subspecies, we have determined that the primary constituent elements 
for the Alameda whipsnake are:
    (1) Scrub/shrub communities with a mosaic of open and closed 
canopy: Scrub/shrub vegetation dominated by low to medium-stature woody 
shrubs with a mosaic of open and closed canopy as characterized by the 
chamise, chamise-eastwood manzanita, chaparral whitethorn, and interior 
live oak shrub vegetation series as identified in the Manual of 
California Vegetation (Sawyer and Keeler-Wolf 1995), A Guide to 
Wildlife Habitats of California (Mayer and Laudenslayer 1988), and 
California Wildlife Habitat Relationship System (CDFG 1998), occurring 
at elevations from sea level to approximately 3,850 ft (1,170 m). Such 
scrub/shrub vegetation within these series form a pattern of open and 
closed canopy which is used by the Alameda whipsnake to provide shelter 
from predators, temperature regulation by providing sunny and shady 
locations, prey-viewing opportunities, and nesting habitat and 
substrate. These features contribute to support a prey base consisting 
of western fence lizards and other prey species such as skinks, frogs, 
snakes, and birds.
    (2) Woodland or annual grassland plant communities contiguous to 
lands containing PCE 1: Woodland or annual grassland vegetation series 
comprised of one or more of the following: blue oak, coast live oak 
(Quercus sp.), California bay (Umbellularia californica), California 
buckeye, and California annual grassland vegetation series (as 
identified in the Manual of California Vegetation (Sawyer and Keeler-
Wolf 1995), A Guide to Wildlife Habitats of California (Mayer and 
Laudenslayer 1988), and California Wildlife Habitat Relationship System 
(CDFG 1998)) are PCE 2. This mosaic of vegetation supports a prey base 
consisting of western fence lizards and other prey species such as 
skinks, frogs, snakes, and birds and provides opportunities for: (1) 
Foraging by allowing snakes to come in contact with and visualize, 
track, and capture prey (especially western fence lizards along with 
other prey such as skinks, frogs, birds); (2) short and long distance 
dispersal within, between, or to adjacent to areas containing essential 
features (i.e., PCE 1 or PCE 3); and (3) contact with other Alameda 
whipsnakes for mating and reproduction.
    (3) Lands containing rock outcrops, talus, and small mammal 
burrows. These areas are used for retreats (shelter), hibernacula, 
foraging, dispersal, and provide additional prey population support 
functions.

Special Management Considerations or Protections

    When designating critical habitat, we assess whether the features 
essential to the conservation of the whipsnake that have been 
identified as PCEs that may require special management considerations 
or protections. Special management is required when threats to the 
species and features essential to its conservation exist and must be 
reduced by management to conserve the species. The greatest threat to 
all six units is continued urban development, which destroys and 
fragments the features essential to the conservation of the subspecies 
and thus the habitat used by the Alameda whipsnake. Second, 
fragmentation and destruction of features essential to the conservation 
of the subspecies and thus the habitat also results from road 
development and widening in all six units. Third, the features 
essential to the conservation of the subspecies are threatened directly 
and indirectly by the effects of fire suppression. Fire suppression 
exacerbates the effects of wildfires through the buildup of fuel (i.e., 
underbrush and woody debris), creating conditions for slow-moving, hot 
fires that completely burn all sources of cover for the Alameda 
whipsnake. Highest intensity fires occur in the summer and early fall, 
when accumulated fuel is abundant and dry. During this period, 
hatchling and adult Alameda whipsnakes are aboveground (Swaim 1994), 
resulting in populations being more likely to sustain heavy losses from 
fires. Fire suppression has led to the encroachment of non-indigenous 
and ornamental trees into grassland habitats, further increasing 
flammable fuel loads in and around Alameda whipsnake habitat. Fire 
suppression has also lead to the change of scrub communities from open/
closed mosaics to closed canopy stands. As described above, Alameda 
whipsnakes prefer scrub communities consisting of an open/closed 
mosaic. The closed scrub canopy also results in a buildup of flammable 
fuels over time (Parker 1987). Special management would be required to 
properly manage fuel load and prevent catastrophic fire within the six 
units.
    Finally, the features essential to the conservation of the 
subspecies and thus the habitat within all six units are subject to 
increased predatory pressure from introduced species, such as rats 
(Rattus spp.), feral pigs (Sus scrofa), and feral and domestic cats 
(Felis domestica) and dogs (Canis familiaris). These additional threats 
become particularly acute where urban development immediately abuts 
Alameda whipsnake habitat. A growing movement to maintain feral cats in 
parklands is an additional potential threat to the Alameda whipsnake. 
The East Bay Regional Park District (EBRP) is currently facing public 
pressure to allow private individuals to maintain feral cats on park 
lands (DelVecchio 1997). Although the actual impact of predation under 
such situations has not been studied, feral cats are known to prey on 
reptiles, including yellow racers (Coluber sp. (Hubbs 1951)), a fast, 
diurnal snake closely related to the Alameda whipsnake (Stebbins 1985). 
Alameda whipsnakes may be adversely affected in areas that lie adjacent 
to urban development because of the associated loss of cover habitats 
in combination with increased native and nonnative predators using 
these areas. Special management of nonnative predators would be 
required within all six units.

[[Page 60616]]

Proposed Critical Habitat Designation

    We are proposing six units as critical habitat for the Alameda 
whipsnake. The critical habitat areas described below constitute our 
assessment of areas that have been determined to be occupied at the 
time of listing, that contain the PCEs, and that may require special 
management. The six areas proposed for designation as critical habitat 
for the Alameda whipsnake are described below.
    Table 1 below provides the approximate area (ac/ha) determined to 
be essential to the Alameda whipsnake and the area proposed for 
exclusion from the final critical habitat designation by unit.

 Table 1.--Areas With Essential Features for the Alameda Whipsnake and the Area Proposed for Exclusion From the
                                       Final Critical Habitat Designation.
----------------------------------------------------------------------------------------------------------------
                                                                    Area with essential      Area Proposed for
                                                                         features           exclusion from the
                                                                 ------------------------ Final Critical Habitat
                              Unit                                                              Designation
                                                                      ac          ha     -----------------------
                                                                                              ac          ha
----------------------------------------------------------------------------------------------------------------
1...............................................................      34,119      13,808       8,108       3,281
2...............................................................      24,524       9,925       4,408       1,784
3...............................................................      27,551      11,150         404         163
4...............................................................      69,598      28,165      46,306      18,739
5A..............................................................      24,723      10,005         246         100
5B..............................................................      18,214       7,371         361         146
6...............................................................       4,612       1,866         272         110
                                                                 -------------
    Total.......................................................     203,342      82,289      60,105      24,323
----------------------------------------------------------------------------------------------------------------

    The approximate area encompassed within each proposed critical 
habitat unit by ownership is shown in Table 2.

                                             Table 2.--Critical Habitat Units Proposed for Alameda Whipsnake
                                    [Area (ac/ha) estimates reflect all land within critical habitat unit boundaries]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Federal              State               Local              Private              Total
                        Unit                         ---------------------------------------------------------------------------------------------------
                                                         ac        ha        ac        ha        ac        ha        ac        ha        ac        ha
--------------------------------------------------------------------------------------------------------------------------------------------------------
1...................................................  ........  ........  ........  ........     8,108     3,281    26,012    10,527    34,119    13,808
2...................................................  ........  ........  ........  ........     4,408     1,784    20,116     8,141    24,524     9,925
3...................................................  ........  ........  ........  ........       404       164    27,146    10,986    27,551    11,149
4...................................................        61        25    13,873     5,615     3,641     1,474    52,022    21,053    69,598    28,165
5A..................................................     2,492     1,009  ........  ........       246        99    21,986