# Endangered and Threatened Wildlife and Plants; Revised Proposed Designation of Critical Habitat for the California Red-Legged Frog (Rana aurora draytonii)

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URL: https://www.frixlaw.com/law-library/documents/fr%3A05-21594

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** November 3, 2005
- **Citation:** 70 FR 66906

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN-1018-AJ16

Endangered and Threatened Wildlife and Plants; Revised Proposed Designation of Critical Habitat for the California Red-Legged Frog (
Rana aurora draytonii
)

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule; revised proposed designation of critical habitat, special rule, reopening of comment period, and notice of availability of the draft economic analysis.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), announce the reopening of a 90-day public comment period for the proposed rule to designate critical habitat for the California red-legged frog (
Rana aurora draytonii
), pursuant to the Endangered Species Act of 1973, as amended (Act), and a concurrent 90-day comment period for the draft economic analysis for this proposed rule. A previous proposed rule to designate critical habitat was published on April 13, 2004 (69 FR 19620). We herein revise those critical habitat boundaries to better reflect lands containing essential features for the California red-legged frog, and we now propose to designate approximately 737,912 acres (ac) (298,622 hectares (ha)) of critical habitat in 23 California counties.

Section 4 of the Act requires us to consider the economic and other relevant impacts of specifying any area as critical habitat. We hereby solicit data and comments from the public on all aspects of this proposal, including data on the economic and other impacts of the designation. We have conducted an analysis of the economic impacts of designating these areas as critical habitat and are announcing the availability of the draft economic analysis for public review.

A special rule is also being proposed to exempt existing routine ranching activities from the prohibitions of the Act because these practices have neutral or beneficial effects on the California red-legged frog. We solicit additional data and information that may assist us in making a final decision on this proposed action.

DATES:

We will accept comments from all interested parties until February 1, 2006. We must receive requests for public hearings, in writing, at the address shown in the
ADDRESSES
section by December 19, 2005.

ADDRESSES:

If you wish to comment on this proposed rule and/or the draft economic analysis, you may submit your comments and materials by any one of several methods:

1. You may submit written comments and information to the Field Supervisor, Sacramento Fish and Wildlife Office, U.S. Fish and Wildlife Service, 2800 Cottage Way, Suite W. 2605, Sacramento, CA 95825.

2. You may hand-deliver written comments and information to our Sacramento Fish and Wildlife Office, at the above address, or fax your comments to 916/414-6712.

3. You may send your comments by electronic mail (e-mail) to
fw1crlf@fws.gov
. For directions on how to submit electronic filing of comments, see the “Public Comments Solicited” section below. In the event that our Internet connection is not functional, please submit comments by the alternate methods mentioned above.

All comments and materials received, as well as supporting documentation used in preparation of this proposed rule, will be available for public inspection, by appointment, during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT:

For general information, information on the special rule, and information about the proposed designation in Alameda, Butte, Calaveras, Contra Costa, El Dorado, Kern, Marin, Merced, Napa, Nevada, San Mateo, Santa Clara, Solano, Stanislaus, and Yuba counties, contact Wayne White, Field Supervisor, Sacramento Fish and Wildlife Office, U.S. Fish and Wildlife Service, 2800 Cottage Way, Suite W. 2605, Sacramento, CA 95825 (telephone 916/414-6600; facsimile 916/414-6712).

For information about the proposed designation in Los Angeles, Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz, and Ventura counties, contact Diane Noda, Field Supervisor, Ventura Fish and Wildlife Office, U.S. Fish and Wildlife Service, 2394 Portola Road, Suite B, Ventura, CA 93003 (telephone 805/644-1766; facsimile 805/644-3958).

For information about the proposed designation in the San Gabriel Mountains of Los Angeles County or Riverside County, contact Jim Bartel, Field Supervisor, Carlsbad Fish and Wildlife Office, U.S. Fish and Wildlife Service, 2730 6010 Hidden Valley Road, Carlsbad, CA 92009 (telephone 760/431-9440; facsimile 760/431-9624).

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

It is our intent that any final action resulting from this proposal will be as accurate as possible. Therefore, we solicit comments or suggestions from the public, other concerned governmental agencies, the scientific community, industry, or any other interested party concerning this proposed rule and its associated draft economic analysis. On the basis of public comment, during the development of the final rule we may find that areas proposed do not have the essential features, are appropriate for exclusion under section 4(b)(2), or are not appropriate for exclusion, in which case they would either be removed from or made part of the final designation. We particularly seek comments concerning:

(1) The reasons why any areas should or should not be determined to be critical habitat as provided by section 4 of the Act, including whether the benefits of designation will outweigh any threats to the subspecies resulting from the designation;

(2) Specific information on the amount and distribution of California red-legged frog and its habitat, and which habitat or habitat components (i.e., physical and biological features) are essential to the conservation of this subspecies and why;

(3) Whether the primary constituent elements for the California red-legged frog as defined in this proposal are biologically and scientifically accurate, specifically;

(a) Whether the requirement for two or more suitable breeding sites within 0.7 mi (1.2 km) is a feature essential to the conservation of the subspecies;

(b) Whether providing 200 ft (60 m) surrounding aquatic and wetland habitat for shelter, forage and predator avoidance is sufficient for conservation of the subspecies;

(4) Land use designations and current or planned activities in or adjacent to the areas proposed and their possible impacts on proposed critical habitat;

(5) Not all of the lands that may contribute to the conservation of the red-legged frog are being proposed as critical habitat. We specifically solicit comment as to whether any other areas should be included and why;

(6) With specific reference to sections 4(a)(3) and 4(b)(2) of the Act, we request information from the Department of Defense (DOD) to assist the Secretary of the Interior in excluding critical habitat on lands administered by, or under the control of, the DOD based on the benefit of an Integrated Natural Resources Management Plan (INRMP) to the

conservation of the subspecies; and information regarding impacts to national security associated with proposed designation of critical habitat; and

(7) Whether the proposed critical habitat unit in southern California with older occurrence records, RIV-2 Arroyo Seco Creek, (see Proposed Critical Habitat designation below) contains features essential to the conservation of the subspecies, and should be designated as critical habitat;

(8) Whether the currently existing unoccupied critical habitat units as identified in the previous
Federal Register
(69 FR 19620; April 13, 2004) (Unit 5) in Tuolumne and Mariposa Counties, and (Unit 31) in Los Angeles County, should remain as critical habitat; and,

(9) Additional information pertaining to the promulgation of a special rule for the California red-legged frog to exempt from take prohibitions under section 9 of the Act existing routine ranching practices located on private and Tribal lands.

(10) Information on how many of the State and local environmental protection measures referenced in the draft economic analysis were adopted largely as a result of the listing of the California red-legged frog, and how many were either already in place or enacted for other reasons;

(11) Whether the draft economic analysis identifies all State and local costs attributable to the proposed critical habitat designation, and information on any costs that have been inadvertently overlooked;

(12) Whether the draft economic analysis makes appropriate assumptions regarding current practices and likely regulatory changes imposed as a result of the designation of critical habitat;

(13) Whether the draft economic analysis correctly assesses the effect on regional costs associated with land use controls that derive from the designation of critical habitat;

(14) The economic analysis indicated potentially disproportionate impacts to areas within San Luis Obispo, Alameda, Contra Costa, Santa Barbara, and San Mateo Counties. Based on this information, we are considering excluding portions of these areas from the final designation per our discretion under section 4(b)(2) of the Act. We are specifically seeking comment along with additional information concerning our final determination for these five areas along with any other areas with potentially disproportionate impacts.

(15) Whether the economic analysis appropriately identifies all costs that could result from the designation, in particular, any impacts on small entities or families; and whether it is appropriate that the analysis does not include the cost of project modifications that are the result of informal consultation only;

(16) Whether there is information about alternate areas that could be used as substitutes for the economic activities planned in areas proposed as critical habitat that would offset the costs and allow for the conservation of critical habitat areas; and

(17) 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 on this proposed rule and/or the draft economic analysis, you may submit your comments and materials concerning this proposal and its associated draft economic analysis by any one of several methods (see
ADDRESSES
section). Please submit electronic comments in ASCII file format and avoid the use of special characters or any form of encryption. Please also include “Attn: RIN 1018-AJ16” 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 phone number 916/414-6600. Please note that the e-mail address
fw1crlf@fws.gov
will be closed out at the termination of the public comment period. In the event that our internet connection is not functional, please submit comments by the alternate methods mentioned above.

Our practice is to make comments, including names and home addresses of respondents, available for public review. 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 above address.

Copies of the proposed rule, draft economic analysis, and information regarding this proposed critical habitat designation are available on the Internet at
http://www.fws.gov/pacific/sacramento
.

Designation of Critical Habitat Provides Little Additional Protection to Species

In 30 years of implementing the Act, (16 U.S.C. 1531
et seq.
), we have found that the designation of statutory critical habitat provides little additional protection to most listed species, while consuming significant amounts of available conservation resources. Our 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). We believe 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.

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 470 species or 37 percent of the 1,264 listed species in the U.S. under our jurisdiction have designated critical habitat.

We address the habitat needs of all 1,264 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. We believe that it is these measures that may make the difference between extinction and survival for many species.

We note, however, that the August 6, 2004, Ninth Circuit judicial opinion,

Gifford Pinchot Task Force
v.
United State Fish and Wildlife Service
) found our definition of adverse modification was invalid. In response to the decision, the Director has provided guidance to the Service based on the statutory language.

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 us 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 us 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 (NOIs) to sue relative to critical habitat, and to comply with the growing number of adverse court orders. As a result, listing petition responses, our 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 us 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). 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

This rule focuses on the reanalysis and re-proposal of critical habitat for the California red-legged frog (
Rana aurora draytonii
). For that reason, much of the information contained in previously published rules has not been included within this notice. For additional information on the biology and habitat requirements of the California red-legged frog, please refer to the following published rules: (59 FR 4888; 61 FR 25813; 65 FR 54891; 66 FR 14626; 69 FR 19619).

Subspecies Description

The California red-legged frog is the largest native frog in the western United States. It is endemic (native and restricted) to California and Baja California, Mexico, at elevations ranging from sea level to approximately 5,000 feet (ft) (1,500 meters (m)). The California red-legged frog gains its name from the typically red or pink color of its posterior abdomen and hind legs. The California red-legged frog is one of two subspecies of the red-legged frog (
Rana aurora
). For a detailed description of the subspecies, see the Recovery Plan for the California Red-legged Frog (Service 2002) and references identified within the plan as well as information in previous
Federal Register
notices (69 FR 19620; 66 FR 14626; 61 FR 25813).

Life History

During breeding season, which typically runs from November through April, males call to females from the margins of ponds and slow streams (Jennings
et al.
, in litt. 1992). Actual mating most commonly occurs in March, but can vary depending on seasonal climatic patterns. Mating pairs enter a breeding position called amplexus, during which the female lays a jellylike mass of 2,000 to 5,000 reddish brown eggs in the water attached to some brace such as emergent vegetation. The eggs are immediately fertilized by the male, and hatch in 6 to 14 days depending on water temperatures (Jennings 1988). The resulting tadpoles, which likely feed on algae (Dickman, 1968 ), metamorphose into adult California red-legged frogs from July to September (Storer 1925; Wright and Wright 1949; N. Scott, in litt. 1998), although some tadpoles have been observed to delay metamorphosis until the following March or April (Bobzien
et al.
2000; Fellers
et al.
2001; R. Smith, in litt. 2004). Adults tend to be nocturnal, while juveniles can be active at any time of day (Hayes and Tennant 1985).

Geographic Range

The historic range of the California red-legged frog extended from Marin County, California, south along the coast to northwestern Baja California, Mexico, and inland as far as the vicinity of Redding in Shasta County, California (Jennings and Hayes 1985; Hayes and Krempels 1986). Recent genetic studies have identified that the subspecies may extend north along the coast into Mendocino County, California (Shaffer
et al.
2004). The range of the California red-legged frog has declined since being described by Storer (1925). Through comparison of historical museum records (1890-1980) and field surveys (1990-1992), Fisher and Shaffer (1996) present evidence of the extirpation (local extermination) of California red-legged frogs from 24 of 28 counties in a limited portion of its historical range. In 1996 when the subspecies was listed, 243 streams or drainages in 22 California counties were documented to contain populations of California red-legged frogs (California Natural Diversity Database (CNDDB) 2004). At the time of listing, California red-legged frogs were believed to have been extirpated from most of the southern Coastal Mountains from Santa Barbara south to Baja California and east along the Transverse (San Gabriel, San Bernadino, Santa Ynez, and Santa Monica Mountains) and Peninsular Ranges (San Jacinto, Santa Rosa, Agua Tibia, Laguna, Santa Ana Mountains). Since listing, two additional occurrences have been discovered south of the Tehachapi Mountains (CNDDB 2005) but may no longer be extant. Four additional occurrences have been recorded in the Sierra Nevada foothills, bringing the total to five known populations, compared to approximately 26 historical records (Berkeley Museum of Vertebrate Zoology 2004; CNDDB 2004; California Academy of Sciences 2004; Barry in litt. 2005). Currently California red-legged frogs are only known from 3 disjunct regions in 26 California counties and is still present in Baja California, Mexico (Grismer 2002; Fidenci 2004; R. Smith and D. Krofta, in litt. 2005).

Threats

For information regarding threats to the subspecies, refer to the previous final listing of the subspecies as well as the previous critical habitat proposal (61 FR 25813; 69 FR 19620). Our understanding of the threats of livestock grazing and stock pond development

described in the previous final listing of the subspecies has changed.

Stock pond and small reservoir impoundments can provide suitable breeding habitat for the California red-legged frog. In many areas the presence of California red-legged frogs is due solely to these small ponded habitats. For example, at the Point Reyes National Seashore in Marin County, an area where there are more than 120 breeding sites with an estimated total adult population of several thousand California red-legged frogs, the majority of the breeding sites are artificial stockponds constructed on lands that have been grazed by cattle for over 150 years (Fellers and Guscio 2004). In the Eastbay Regional Park District lands in Contra Costa and Alameda Counties, 43 of 179 ponds surveyed which were exposed to grazing, and were characterized with and without emergent vegetation, supported successful breeding frog populations often exhibiting high rates of annual breeding (Bobzien
et al.
2000). For more information concerning the importance of stock ponds to the subspecies see the Special Rule section below.

The Service now recognizes that managed livestock grazing at low to moderate levels has a neutral or beneficial effect on California red-legged frog habitat (Bobzien et al. 2000) by keeping a mix of open water habitat and emergent vegetation which is beneficial to the subspecies. In some cases, without managed grazing, stock ponds would quickly fill with emergent vegetation resulting in habitat loss (Bobzien pers. comm. 2005).

However, numerous studies, summarized by Kauffman and Krueger (1984) and Belsky
et al.
(1999), have shown that unmanaged livestock grazing (overgrazing) can negatively affect riparian and instream aquatic habitat. Some of the effects of unmanaged grazing include: Higher instream water temperatures resulting from reduction or removal vegetation, channel down cutting, lowered water tables and loss of plunge pools which results in direct loss of pool habitats for the California red-legged frog (Patla and Keinath 2005), as well as diminished water quality through increased sediment loads and nutrient levels (Belsky
et al.
1999).

Habitat

California red-legged frogs live in a Mediterranean climate, which is characterized by temporal and spatial changes in habitat quality. During a period of abundant rainfall, almost the entire landscape, including breeding ponds and streams may become suitable habitat for the adults. Conversely, habitat use may be drastically confined during periods of prolonged drought. Due to this variability, population sizes can vary widely from year to year. During favorable years, California red-legged frogs can produce large numbers of dispersing young, resulting in an increase in the number of occupied sites. In contrast, California red-legged frogs may temporarily disappear from an area during periods of extended drought. Therefore, it is essential to provide for sites that can be recolonized by dispersing individuals (Semlitsch 2000).

The habitats used by this subspecies typically change in extent and suitability in response to the dynamic nature of floodplain and fluvial processes (
i.e.
, natural water flow and sedimentation regimes that, in flux, create, modify, and eliminate deep pools, backwater areas, ponds, marshes, and other aquatic habitats). Rangewide, and even within local populations, the California red-legged frog uses a variety of areas, including various aquatic, riparian, and upland habitats. In some cases, they may complete their entire life cycle in a particular habitat (
i.e.
, a pond is suitable for all life stages), and in other cases, they may seek multiple habitat types depending on climatic conditions or distance between and availability of wetland and hydric environments.

Despite the California red-legged frog's ability to utilize multiple habitat types, there are certain habitat features they require. Most important is a breeding pond or slow flowing stream reach or plunge pool within a stream with some type of vegetative or other material to attach their egg masses, that holds water long enough for tadpoles to complete their metamorphoses and juveniles able to survive outside of water. California red-legged frogs often disperse from their breeding habitat to utilize various aquatic, riparian, and upland summer habitats during their migrations from one area to another. However, it is also common for individuals to remain in the breeding area on a year-round basis.

Aquatic breeding habitat must remain hydrated until at least July, and preferably September, so the tadpoles can complete their metamorphoses. Drydowns after that time can be beneficial because they help prevent the establishment of predatory fish or bullfrogs (Hayes and Jennings 1989; Cook 1997; N. Scott, in litt. 1998). Water quality requirements for eggs and tadpoles include low salinity (below 4.5 parts per thousand (ppt) for eggs, up to 7.0 ppt for tadpoles) (Jennings and Hayes 1990; M. Jennings, in litt. 1994), and temperatures below about 73° Fahrenheit (23° Celsius) (Cook 1997; Nussbaum
et al.
1983). Water bodies free of bullfrogs and nonnative predatory fish, are optimal but California red-legged frog populations can persist in the presence of one or the other of these predators (Kiesecker and Blaustein 1998; Lawler
et al.
1999).

In Northern California, few California red-legged frog populations occupy naturally occurring wetland environments. Historically, as natural wetlands and streams were converted for agriculture, flood control, and urban development, California red-legged frogs colonized small artificial impoundments created by cattle ranchers for the purpose of providing water for their cattle. Our understanding of the role of stock ponds in the conservation of the California red-legged frog has evolved since listing. Without these stock ponds, the range of the California red-legged frog would be limited further in this region.

Dispersal

Adult California red-legged frogs may disperse from breeding sites at any time of year. Dispersing adult California red-legged frogs in northern Santa Cruz County traveled distances from 0.25 miles (mi) (0.4 kilometers (km)) to more than 2.0 mi (3.2 km) without apparent regard to topography, vegetation type, or riparian corridors (Bulger
et al.
2003). California red-legged frogs have also been radio tracked in East Las Virgenes Creek, Ventura County which has a Mediterranean climate characterized by highly variable rainfall (R. Smith, in litt. 2005). Habitat includes a well-defined creek and riparian zone with permanent deep pools. In contrast to California red-legged frog movements in Santa Cruz County, Smith
et al.
have found movements of California red-legged frogs to be substantially less, with typical movements of 9—16 feet (3—5 meters) from the water's edge. Maximum distance moved was 48 feet (15 meters) (R. Smith, in litt. 2005). Many newly metamorphosed juveniles tend to disperse short distances initially from July through September, and then move farther away from the breeding habitat during warm rain events (Monk 1997; M. Jennings, in litt. 2000). Bobzien
et al.
(2000) observed juveniles inhabiting a wide variety of habitats while adults primarily inhabited deep pools. They postulated that juveniles might segregate themselves away from adults to escape predation and competition.

For reasons that are currently unclear, juveniles tend to disperse away from

aquatic habitat occupied by adults. Juvenile dispersal is essential for recolonizing temporarily extirpated habitat and preventing genetic isolation because juveniles disperse in more directions, and for longer distances than do migrating adults (Wright, in litt. 1999; Bulger
et al.
2003). Dispersal habitat for juveniles can be almost anything that provides sheltering vegetation or scattered wetlands or streams. This includes forested areas, nonnative grasslands, and even croplands, but is not known to include urbanized or suburban areas, suburban developments, or areas separated from breeding habitat by impassible barriers. Impassible barriers include wide or fast flowing rivers and streams, lakes greater than 50 ac (20 ha), and heavily traveled roads without underpasses or culverts (Reh and Seitz 1990; Fahrig
et al.
1995). Juveniles dispersing along riparian corridors may have higher survivorship, as sheltering vegetation and suitable aquatic habitat are both more common in such corridors (M. Jennings, in litt. 2000). Juveniles appear to have less strict requirements for aquatic habitat than adults, and tend to segregate away from adults in water bodies that are shallower or faster moving than those typically used for breeding (Hayes and Jennings 1989; Bobzien pers. comm. 2000; M. Jennings, in litt. 2000).

The long-term probability of the survival and recovery of California red-legged frogs is dependent upon the protection of existing breeding habitat and associated uplands (Fellers and Kleeman 2005), the movements of individuals between aquatic patches, and the ability to recolonize newly created or vacated habitats. Recolonization, which is vital to the recovery of this subspecies, is dependent upon landscape characteristics including the distance between suitable breeding and non-breeding aquatic habitat, and fragmentation of interconnecting habitat (Vos and Chardon 1998).

Previous Federal Action

On June 8, 2001, various homebuilding and commerce organizations filed a lawsuit in the U.S. District Court for the District of Columbia challenging our designation of critical habitat for the California red-legged frog (
Home Builders Ass'n of Northern California,

et al.
v.
Norton,

et al.
, Civ. No. 01-1291 (RJL) (D. D.C.)). On November 6, 2002, the court entered a consent decree remanding the designation to the Service to conduct a new economic analysis. The consent decree vacated the critical habitat designation for the California red-legged frog with the exception of Units 5 and 31, which were not known to be occupied by the California red-legged frog, and ordered us to promulgate a proposed revised designation by March 2004, and a final revised rule by November 2005. We published a revised critical habitat proposal on April 13, 2004 (69 FR 19620), which proposed the re-designation of the previously established units. Due to comments received, our own re-evaluation of our selection criteria and the primary constituent elements required by the California red-legged frog (see below), we now issue this revised proposed critical habitat designation and its associated draft economic analysis.

Critical Habitat

Critical habitat is defined in section 3 of the Act as—(i) the specific areas within the geographical area occupied by the species, at the time it is listed in accordance with the provisions of section 4 of this 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 the species at the time it is listed in accordance with the provisions of section 4 of this Act, upon a determination by the Secretary that such areas are essential for the conservation of the species.

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 may 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 geographical area occupied by the species 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, as defined at 50 CFR 424.12(b)).

Specific areas within the geographical area occupied by the species 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 geographic 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.

Our Policy on Information Standards Under the Endangered Species 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 our decisions represent the best scientific data available. They require our 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 contain features essential to the conservation of a species, 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 what we know at the time of designation. Habitat is often dynamic, and 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, to the regulatory protections afforded by the section 7(a)(2) of the Act jeopardy standard, and take under sections 9 and 10 of the Act if they support populations, 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 California red-legged frog. The sources of data used in identifying critical habitat include information in our files regarding habitat requirement of the subspecies including the data sources mentioned in the previous proposal (69 FR 19620), as well as information provided by commenters to that proposal. We also reviewed available information that pertains to the habitat requirements of this subspecies including data in 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 Geographic Information System (GIS) coverages. We designated no areas outside the geographic area presently occupied by the subspecies.

In re-proposing critical habitat for the California red-legged frog, we changed our previous methodology of using the watershed as our primary mapping unit for the subspecies. Our current methodology includes a more precise mapping of the physical and biological features essential to the conservation of the California red-legged frog (i.e., primary constituent elements (PCEs)) (see below). This has resulted in significant differences between the units we proposed in April, 2004 (69 FR 19620) and those we are proposing here. Additional changes have resulted from minor adjustments to the PCEs, and from an increased emphasis in the criteria on establishing the likely limits of occupied areas. See the section below, Criteria Used to Identify Critical Habitat, for a detailed listing of our selection criteria.

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 designate as critical habitat, we are required to consider those physical and biological features (PCEs) that are essential to the conservation of the species, within areas occupied by the species at the time of listing, 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, 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.

Each of the areas designated in this rule have been determined to contain sufficient PCEs to provide for one or more of the life history functions of the California red-legged frog. As a result, the existing conditions at the time of designation will be included in the baseline in any consultation conducted subsequent to this designation. Federal actions that may result in alteration of these conditions will be subject to an analysis to determine whether adverse modification or destruction of critical habitat has occurred.

Aquatic Breeding Habitat

California red-legged frogs typically lay eggs between December and early April. Eggs hatch within 6 to 14 days depending on water temperatures and require approximately 20 days to develop into tadpoles. Tadpoles in turn require anywhere between 11-20 weeks to develop into terrestrial frogs (Bobzien
et al.
2000; Storer 1925; Wright and Wright 1949). Water bodies suitable for tadpole rearing must remain watered at least until the tadpoles metamorphose into adults, typically between July and September. Adult California red-legged frogs can survive in moist upland areas after breeding habitat has dried, and can live several years to make new breeding attempts. Therefore, aquatic breeding habitat need not be available every year, but it must do so often enough to maintain a California red-legged frog population during most years.

Aquatic habitat is essential for providing space, food, and cover, necessary to sustain all life stages of California red-legged frogs. It consists of virtually all low-gradient fresh water bodies, including natural and manmade (e.g., stock) ponds, backwaters within streams and creeks, marshes, lagoons, and dune ponds. It does not include deep lacustrine water habitat (e.g., deep lakes and reservoirs 50 ac (20 ha) or larger in size).

The aquatic habitat described as the first PCE is essential for frog breeding and for providing space, food, and cover necessary to sustain early life history stages of larval and juvenile California red-legged frogs. To be considered essential breeding habitat, the aquatic feature must have the capability to hold water for a minimum of 15 weeks in all but the driest of years. This is the average amount of time needed for larvae to grow into metamorphosed juveniles so they can become capable of surviving in upland habitats. California red-legged frogs usually have completed metamorphosis between July and September. During periods of drought or less-than-average rainfall, these sites may not hold water long enough for individuals to complete metamorphosis. However, these sites would still contain features that are essential because they constitute breeding habitat in years of average rainfall. Without aquatic breeding habitats, the California red-legged frog would not survive, reproduce, develop juveniles, and grow into adult individual California red-legged frogs that can complete their life cycles.

Non-Breeding Aquatic Habitat

The aquatic habitat described as the second PCE is essential for providing the space, food, and cover necessary to sustain California red-legged frogs. Non-breeding habitat consists of those aquatic elements identified above, but would also include, but not be limited to, other wetland habitats such as intermittent creeks, seeps, and springs. California red-legged frogs can use large cracks in the bottom of dried ponds as refugia to maintain moisture and avoid heat and solar exposure (Alvarez 2004). Without these non-breeding aquatic features California red-legged frogs would not be able to survive drought periods, or be able to disperse to other breeding habitat.

Upland Habitat

Upland and riparian habitats associated with aquatic habitat is essential to maintain California red-legged frog populations associated with essential aquatic habitat. The associated upland and riparian habitat provide food and shelter sites for California red-legged frogs and assist in maintaining the integrity of aquatic sites by protecting them from disturbance and supporting the normal functions of the aquatic habitat. Upland habitat associated with occupied wetland habitat often contains blackberry (
Rubus
sp.) and other upland perennial species that provide for shelter from predatory species and forage habitat (Service 2002).

Upland habitat that contains the features essential to the conservation of the species consists of natural areas within 200 ft (60 m) of the edge of the riparian vegetation or dripline, or no further than the watershed boundary. This is based on the dispersal capabilities of the subspecies (see Dispersal Habitat below), and also research that has found in one study that the subspecies was capable of inhabiting upland habitats within 200 ft (60 m) of aquatic habitat for continuous durations exceeding 20 days (Bulger
et al.
2003), and in another study, California red-legged frogs were observed inhabiting riparian habitat for durations up to 77 days (Rathbun
et al.
1993). California red-legged frogs often disperse from their breeding habitat to forage and seek upland habitat if aquatic habitat is not available. Upland habitat includes structure that provides shade, moisture, and cooler temperatures. This structure may be natural such as the spaces under boulders or rocks and organic debris such as downed trees or logs; or it could be manmade including industrial debris and agricultural features, such as drains, watering troughs, abandoned sheds, or under stacks of hay or other vegetation. California red-legged frogs also use small mammal burrows and moist leaf litter (Jennings and Hayes 1994; Fellers and Kleeman 2005).

Dispersal Habitat

Dispersal habitat provides connectivity among California red-legged frog breeding habitat (and associated upland) patches. While California red-legged frogs can pass many obstacles, and do not require a particular type of habitat for dispersal, the habitat connecting breeding locations and other aquatic habitat must be free of barriers that prevent California red-legged frogs from dispersing. Dispersal habitat that is designated in this rule consists of upland and wetland habitat contiguous with breeding and non-breeding habitat which is free of barriers that connect two or more patches of breeding habitat within 0.7 mi (1.2 km) of one another. Dispersal barriers include heavily traveled roads (Vos and Chardon 1998) that possess no bridges or culverts; moderate to high density urban or industrial developments with large expanses of asphalt or concrete that do not contain the PCEs or features essential to the subspecies; and large reservoirs over 50 ac (20 ha) in size that contains predatory fish. Agricultural lands such as row crops, orchards, vineyards, and pastures do not constitute barriers to California red-legged frog dispersal.

California red-legged frogs have been documented to travel 2.2 mi (3.6 km) from nonbreeding to breeding habitats (Bulger
et al.
2003). These long distance movements are migrations rather than use of corridors for moving between habitats (N. Scott and G. Rathbun, in litt. 1998). These movements have also been found to be with apparent disregard to topography, vegetation type, or riparian corridors (Bulger
et al.
2003; Fellers and Kleeman 2005). We conclude the 2.2 mi (3.6 km) is likely the upward limit of dispersal capability for the California red-legged frog and that the 0.7 mi (1.2 km) dispersal element will ensure that connectivity between breeding habitats will be maintained within areas designated as critical habitat. This 0.7 mi (1.2 km) dispersal element also includes elements of non-aquatic habitat (i.e., summer habitat) for shelter.

Primary Constituent Elements for the California Red-Legged frog

Based on our current knowledge of the life history, biology, and ecology of the California red-legged frog 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 California red-legged frog are:

(1)
Aquatic Breeding Habitat.
Standing bodies of fresh water (with salinities less than 7.0 ppt), including natural and manmade (e.g., stock) ponds, slow moving streams or pools within streams, and other ephemeral or permanent water bodies that typically become inundated during winter rains and hold water for a minimum of 15 weeks in all but the driest of years. This would be the time necessary for the subspecies to complete the aquatic portion of its life cycle.

(2)
Non-Breeding Aquatic Habitat.
Fresh water habitats as described above which may or may not hold water long enough for the subspecies to hatch and complete its aquatic lifecycle but which does provide for shelter, foraging, predator avoidance, and aquatic dispersal habitat for juvenile and adult California red-legged frogs. Other wetland habitat which would be considered to meet these elements would include, but are not limited to, plunge pools within intermittent creeks, seeps, quiet water refugia during high water flows, and springs of sufficient flow to withstand the summer dry period.

(3)
Upland Habitat.
Upland areas within 200 ft (60m) of the surrounding aquatic and wetland habitat comprised of various vegetational series such as grasslands, woodlands, and/or wetland/riparian plant species. Upland habitat includes natural or manmade structures such as the spaces under boulders or rocks and organic debris such as downed trees or logs; as well as agricultural features and light construction debris, such as drains, watering troughs, abandoned sheds, or under stacks of hay, brush piles, or other vegetation. California red-legged frogs also use small mammal burrows and moist leaf litter as cover (Jennings and Hayes 1994; Fellers and Kleeman 2005). This upland habitat provides the California red-legged frog shelter and shade, moisture, cooler temperatures, prey base, foraging opportunities, and predator avoidance.

(4)
Dispersal Habitat.
Accessible upland or wetland dispersal habitat within designated units and between occupied locations within 0.7 mi (1.2 km) of each other that allow for movement between such sites. Dispersal habitat includes various natural habitats and altered habitats such as agricultural fields, which also do not contain barriers to dispersal, such as heavily traveled roads (Vos and Chardon 1998) that possess no bridges or culverts. Dispersal habitat does not include moderate to high density urban or industrial developments with large expanses of asphalt or concrete and large reservoirs over 50 ac (20 ha) in size, which do not contain those features identified in PCE 1, 2, or 3. Accessible dispersal habitat provides opportunities for the California red-legged frog to move freely across the landscape in search of adjacent breeding and non-breeding habitats. Accessible dispersal habitat is considered essential and provides for: (1) Opportunities 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) recolonization of or recruitment into breeding habitat after local extirpations.

Criteria Used To Identify Critical Habitat

In our proposed designation of critical habitat for the California red-legged frog, we selected areas based on the best scientific data available that possess those physical and biological features essential to the conservation of the subspecies, and that may require special management considerations or protection. We included areas which were occupied at the time of listing as well as some areas subsequently identified as occupied. We found that the majority of newer occurrence records were within areas already known to support the California red-legged frog. We identified proposed critical habitat units that have the highest likelihood to be self-sustaining on the basis of density of California red-legged frog occurrences, and based our definition of the primary constituent elements on the kind, amount, and quality of habitat associated with those occurrences. The proposed units contain sufficient PCEs to support behaviors we have determined are essential to the conservation of the subspecies.

Throughout the development process, we avoided identifying areas with single occurrences for designation unless such areas were considered unique or had other biological significance. Further, we made an effort to avoid developed areas, such as housing and commercial developments, that are unlikely to contribute to the conservation of the California red-legged frog. We also avoided fragmented areas such as those surrounded by development. Areas within the boundaries of the mapped units, such as buildings, roads, parking lots, railroads, canals, levees, airport runways and other paved areas, lawns, and other urban landscaped areas are not critical habitat and are not included in this designation. Federal actions limited to these areas would not trigger a section 7 consultation, unless they affect the subspecies and/or the PCEs in adjacent critical habitat. We avoided known areas of intensive agriculture. Agricultural lands may have been included if they were within areas identified as necessary for dispersal or connectivity between known occurrences.

We considered several criteria in the selection of areas which contain the essential features for the California red-legged frog and focused on designating units: (1) Throughout the current geographic, elevational, and ecological distribution of the subspecies; (2) which would maintain the current population structure across the subspecies' range; (3) that retain or provide for connectivity between breeding sites that allows for the continued existence of viable and essential metapopulations, despite fluctuations in the status of subpopulations; (4) that possess large continuous blocks of occupied habitat, representing source populations and/or unique ecological characteristics; and (5) contain sufficient upland habitat around each breeding location to allow for sufficient survival and recruitment to maintain a breeding population over the long term.

We first determined the occupancy status of areas. Areas were considered to possess extant populations if California red-legged frogs have been documented in that area since 1976. We used the final listing rule to establish occupancy at the time of listing. All other designations were based on occupancy data collected since listing. Our designation does not include all occupied areas. However those areas occupied takes into consideration theories of metapopulation persistence, on-the-ground survey data, and California red-legged frog longevity. We believe that persistence of individual populations is critical to the viability of a metapopulation structure. Bulger
et al.
(2003) found more than 75 percent of California red-legged frogs are resident at permanent aquatic habitats over the course of a year, thereby providing local population stability. Survey data provided to us during the development of this proposed critical habitat rule show an average persistence of 19 years for California red-legged frog populations. Additionally, maximum longevity of male and female California red-legged frogs is 8 and 10 years respectively (Jennings
et al.
1992) which also contributes to generational and metapopulation stability.

The extant occurrences within the proposed critical habitat units comprise approximately 63 percent of extant occurrences within the range of the subspecies. We critically evaluated records in which the exact site location was not precisely identified or could not be confirmed, and removed those locations from our analysis. We then selected areas that are inhabited by populations (source populations) that are capable of maintaining their current population levels and capable of providing individuals to recruit into subpopulations found in adjacent areas. We also selected several areas which have other unique ecological significance, with the goal of maintaining the full range of the habitat variability and evolutionary adaptation in the subspecies. These include areas on the periphery of the current range and elsewhere that represents the distribution of the subspecies, and areas that provide connectivity among source populations or between source populations.

The proposed critical habitat units were delineated by creating approximate areas for the units by screen digitizing polygons (map units) using ArcMap (Environmental Systems Research Institute, Inc.), a computer GIS program. The polygons were created by overlaying extant at time of listing and subsequent to listing California red-legged frog occurrence locations with a 0.7 mi (1.2 km) radius. This distance was used as a guide for mapping the essential features around locations where California red-legged frog populations are present (see Dispersal Habitat above). As stated above, California red-legged frogs have been documented to disperse from ponds and streams a distance over 2.0 mi (3.2 km) (Bulger
et al.
2003). However, based on a review of the most current literature and information gathered in development of the Recovery Plan for the subspecies, we have determined that the 2.0 mi (3.2 km) distance is toward the maximum dispersal distance for the subspecies during a single season, and that the 0.7 mi (1.2 km) distance is more reflective of the average dispersal distance for the California red-legged frog (Rathbun
et al.
1993; Scott and Rathbun, in litt 1998; Wright, in litt. 1999; Bulger
et al.
2003; T. Tatarian, in litt. 2005; Fellers and Kleeman 2005). Although the studies discussed above provide an approximation of the distances that California red-legged frogs can move from their aquatic habitats, breeding ponds, and other wetland habitats in search of suitable upland refugia or other breeding locations, we recognize that upland habitat features will influence California red-legged frog movements in a particular landscape. As a result, we made adjustments to the upland areas to include additional areas up to the watershed boundaries or to include habitat containing the PCEs beyond the 0.7 mi (1.2 km) distance where appropriate to aggregate clumps of occurrences. In other some instances, we reduced the areas to remove non-habitat (those not exhibiting the PCEs) from the proposed designation including agricultural, developed, disturbed, or fragmented lands.

We evaluated the resulting units (delineating geographic range and potential suitable habitat), refined

elevation and hydrologic ranges, and identified areas not containing the essential features (
i.e.
, not containing PCEs) (see Primary Constituent Elements section). We excluded areas that do not contain sufficient PCEs to support one or more of the species' life processes or which had low quality PCEs because: (1) The area is highly degraded and is likely not restorable; (2) the area is small, highly fragmented, or isolated and may provide little or no long-term conservation value; and (3) other areas within the geographic region were determined to be sufficient to meet the conservation needs of the subspecies.

Throughout the designation process, when selecting areas of critical habitat, we made an effort to avoid developed areas, such as housing developments and commercial developments that are unlikely to contribute to the conservation of the California red-legged frog. However, we were not able to map critical habitat in sufficient detail to exclude all developed areas, or other lands unlikely to contain the PCEs.

Further refinement of the preliminary areas as described above was based on the extent of aquatic habitat extent, stream reach, upland dispersal distance and watershed boundaries. We focused on areas of high California red-legged frog abundance, areas to maintain connectivity, and/or areas of unique ecological significance. Refined unit boundaries were delineated using watershed boundaries from the State of California's CALWATER watershed classification system (version 2.2) using the smallest (planning watersheds) watershed designation. Visual inspection of mapped California red-legged frog occurrence records revealed un-surveyed regions surrounded by surveyed regions, mostly in highly developed areas. Rather than designating critical habitat in the development fringe, we designated in areas where fewer surveys have been conducted but where California red-legged frogs are likely to occur based on similarity of habitat and presence of PCEs. In areas where planning watersheds were large and/or had significantly altered hydrologically, we used alternative structural, political, or topographic boundaries (
e.g.
, roads, county boundaries, ridgeline features, elevation contour lines) as critical habitat boundaries because in these areas the benefits of using planning watersheds were limited in that they included areas outside the subspecies' dispersal distance or were of little conservation value for the California red-legged frog.

Summary of Changes From Previous Proposed Critical Habitat

Following the publication of the previous proposed rule (69 FR 19620), we revised this current proposed critical habitat based on new information, re-evaluation of existing information, and public comments. We also revised the methodology for determining the specific features that are essential to the conservation of the California red-legged frog and mapping them to areas. Our previous proposal utilized aggregations of watersheds that contained areas of high California red-legged frog abundance and that maintained connectivity and/or included areas of unique ecological significance. Portions of these areas were outside the dispersal capabilities of the frog and not all the areas within the designation contained the features considered essential to the California red-legged frog. This has resulted in a complete re-analysis of the areas previously proposed and new areas where the frog had been recently documented to ensure a more thorough and scientifically sound designation of critical habitat. This re-analysis resulted in the removal of specific lands determined not to contain features essential to the conservation of the frog, and the inclusion of additional areas. The Service believes that this task was necessary to ensure compliance with recent court decisions on critical habitat and to ensure appropriate consideration of public comments and new information in the rulemaking process. Upon identification of lands containing features essential to the conservation of the frog following the revised methodology, the Service began to refine its mapping methodology from using a landscape-level watershed as the primary mapping unit in the previous proposal to a methodology that is more precise in delineating areas that contain the physical and biological features essential to the frog and thus meet the statutory definition of critical habitat. This new methodology employs an average dispersal distance of 0.7 miles around extant populations of frogs to capture the features essential to their conservation.

In this proposal we have eliminated areas that do not have essential features and refined unit boundaries in accordance with the criteria for determining the essential features described above. Our criteria for determining essential features targeted areas known to be occupied by California red-legged frog at the time of listing or determined to be occupied since the time of listing, or areas of high-quality habitat likely to be occupied based on proximity to known occurrences, contiguous habitat, and dispersal capabilities of the California red-legged frog. Our refined proposal includes large blocks of contiguous habitat that provide geographic distribution across the range of the subspecies, contains high-quality habitat, allows for the long-term viability of the subspecies, represents the full range of habitat and environmental variability the subspecies occupies, avoids conflict with existing commercial and residential development, focuses on public lands where available, and, where possible, overlaps with other critical habitat designations.

As a result of our refined approach, the current proposal includes units that more accurately reflect the requirements and known distribution of the California red-legged frog. Based on our refined approach, some areas previously proposed as critical habitat are no longer included in this new proposed designation, and based on new occurrence records, several areas where units did not exist in the previous designation we have determined contain the features that are essential and we are now proposing for designation as critical habitat. We are proposing to not designate two currently designated unoccupied units (Unit 5 in Tuolumne and Mariposa Counties and Unit 31 in Los Angeles County) identified in our previous designation (66 FR 14626) and proposal (69 FR 19620). The criteria used in the current proposal identified areas across the known range of the subspecies and included areas which are essential for the conservation of the subspecies. We consider that the currently occupied proposed critical habitat units would be sufficient to conserve the species and that the non-occupied units would only supplement areas needed for conservation of the subspecies. We are seeking comment on the status of these units, whether they should remain as critical habitat and whether these areas contain the features which are essential to the conservation of the subspecies.

In our re-evaluation of our April 13, 2004 (69 FR 19620), proposed critical habitat, we identified that a technical error was present in 50 CFR 17.11 concerning the extent of the geographic range for which the California red-legged frog is listed. The extent of the geographic range has been corrected to reflect the entire range of the subspecies.

Special Management Considerations or Protections

When designating critical habitat, we assess whether the areas determined to be occupied at the time of listing and contain the PCEs may require special management considerations or protections. As we undertake the process of designating critical habitat for a species, we first evaluate lands defined by those physical and biological features essential to the conservation of the species for inclusion in the designation pursuant to section 3(5)(A) of the Act. Secondly, we evaluate those features to assess whether they may require special management considerations or protections. As discussed throughout this proposed rule, our previous final designation of critical habitat for the California red-legged frog (66 FR 14626, March 13, 2001) and in our final recovery plan for the subspecies (Service 2002), threats to those features that define important habitat (primary constituent elements) for the California red-legged frog include but are not limited to: trematode and chytrid fungus disease, direct and indirect impacts from some human recreational activities, flood control maintenance activities, water diversions, unmanaged overgrazing activities, competition and predation by nonnative species, and habitat removal and alteration by urbanization.

Pathogens and parasites have been implicated in the decline of other frog species, but there has not been a systematic examination of how disease may adversely affect California red-legged frog populations. Trematode-induced malformations and chytrid fungus disease have been identified in some California red-legged frogs in Elkhorn Slough National Estuarine Research Reserve and in frogs within East Bay Regional Park District (Bobzien pers. comm. 2005). It has been suggested that increased levels of UV-B radiation or air pollutants cause a weakening of the immune system which could increase the susceptibility of frogs to natural diseases (Kiesecker
et al.
2001; Blaustein
et al.
2003).

Routine road maintenance, trail development, and facilities construction associated with parks and other public lands, in or adjacent to California red-legged frog habitat can degrade habitat quality. Heavy recreational use of parks (
e.g.
, fishing, hiking, use of developed sites, dispersed camping) can also degrade habitat for the California red-legged frog. People tend to congregate around aquatic areas and can trample vegetation, trample frog eggs and tadpoles, increase noise levels, and change the environment.

Routine flood control maintenance, which typically includes vegetation removal, herbicide spraying, shaping and riprapping of banks to control erosion, and dredging of creeks and rivers, can result in degradation of California red-legged frog habitat. Widespread channelization of watercourses for flood control and water diversion has eliminated habitat along small to medium-sized watercourses (Harding 1960), and has allowed the proliferation of non-native aquatic species. Management of water flows for flood control also has the potential to adversely impact California red-legged frogs. For example, in San Mateo County, poorly timed releases of storm water flows from Horse Stable Pond at Sharp Park in February 1992, resulted in exposure and desiccation of 62 California red-legged frog egg masses (T. Steiner in litt. 1994).

Water diversion and impoundment for irrigation, can reduce the flows necessary to support adequate aquatic habitat for frogs and other species. The California coast supports several agricultural activities including artichoke production, flower nurseries, and other irrigated crops that require the use of irrigation ponds. Water is collected during the winter months from rainfall and is also pumped out of coastal drainages into ponds. These ponds typically grow shoreline vegetation such as cattails, tules (Scirpus spp.) and horsetails (Equisetum spp.), and with proper water management can provide high quality breeding habitat. However, farmers often start irrigating crops during the late spring, and continue through summer. As water is drawn down, egg masses can be exposed and desiccate. Although the outlets may be screened, the pumps used are powerful enough to suck tadpoles and juveniles against the screen and can crush individuals. Depending upon the size of ponds, they also may be drawn down to such an extent that they completely dry out or are shallow enough to allow significant predation of frogs (particularly tadpoles that have not fully metamorphosized).

Continued colonization of existing habitat by, and competition with, predatory nonnative species (Fisher and Shaffer 1996; Lawler
et al.
1999) is one of the most significant threats to California red-legged frogs. Twedt (1993) analyzed stomach contents of 22 bullfrogs in Humboldt County, California and found 9.1 percent of the prey items consisted of northern red-legged frog juveniles. Cook (1997) also analyzed stomach contents of eight bullfrogs collected in Sonoma County and found California red-legged frog tadpoles in two of them. However, predation of California red-legged frogs by bullfrogs is likely to be dependant on the density of bullfrogs (Cook1997) and habitat segregation may lessen the impact of predation on California red-legged frogs (Twedt 1993). Bobzien
et al.
(2000) suggest the presence of nonnative predators adversely affects the distribution of California red-legged frogs within East Bay Regional Park lands, leading to local extirpation in some areas. Lawler
et al.
(1999) found mosquitofish did not affect the survival of California red-legged frog tadpoles, however tadpoles weighed 34 percent less at metamorphosis than did tadpoles that developed in absence of mosquitofish competition.

Urban and suburban developments often leave isolated habitat fragments and create barriers to frog dispersal. Another consequence of urbanization is the change in hydroperiod of historically ephemeral drainages to perennial streams (often due to wastewater outflows), which allows the proliferation of non-native predators (M. Moore and M. Westphal in litt. 1997). Other consequences include channelization of creeks (which reduces or eliminates breeding sites), increased potential for toxic runoff from developments, and increased suitability for predators such as raccoons.

We believe that the features essential to the conservation of the subspecies in each area proposed for designation as critical habitat may require some level of special management and/or protection to address the current and future threats to the California red-legged frog to ensure the conservation of the subspecies.

Proposed Critical Habitat Designation

The areas we are proposing as critical habitat currently provide all of those habitat components necessary to meet the primary biological needs of the California red-legged frog. We did not include all areas currently occupied by California red-legged frogs, only areas possessing large populations, that represent unique ecological characteristics or adaptations, or that represent the historic geographic area where California red-legged frogs can be re-established. No unoccupied habitat is being proposed as critical habitat.

Table 1. Approximate area exempt from proposed critical habitat for the California red-legged frog pursuant to sections 4(a)(3) of the Act.

Location (unit) Vandenberg Air Force Base
Lands containing essential features
ac
ha
Area exempt from critical habitat designation
ac
ha

STB-2
4,922
1,992
4,922
1,992

STB-4
8,691
3,517
1,011
409

Table 2. Approximate area (acres (as) (hectares ha)) of locations supporting features essential to conservation of the California red-legged frog fitting the selection criteria for proposed critical habitat and (first column), areas excluded from critical habitat pursuant to section 4(b)(2) of the Act (second column), and areas proposed as critical habitat (third column) for the California red-legged frog.

Areas with essential features
ac
ha
Excluded areas
ac
ha
Total proposed critical habitat
ac
ha

743,845
301,023
5,933
2,401
737,912
298,622

Table 3. Critical Habitat Units Proposed for the California red-legged frog [Area estimates (acres (ac) (hectares ha)) reflect the entire area within the proposed critical habitat unit boundaries, areas supporting PCEs may be less within each unit.]

Unit
Federal
ac
ha
State
ac
ha
Local
ac
ha
Private
ac
ha
Military
ac
ha

BUT-1
3,234
1,309
137
56

1,922
778

YUB-1
2,489
1,007

3,833
1,551

NEV-1
3,158
1,278
90
36

5,038
2,039

ELD-1
463
188

8,791
3,558

CAL-1
7
3

4,442
1,798

NAP-1

2,524
1,022

MRN-1

1,046
423
21,513
8,706

MRN-2
25,995
10,520

SOL-1

9,245
3,741

CCS-1A

3,475
1,406
730
296

CCS-1B

3,297
1,334
16,437
6,652

ALA-1A

1,276
516
16,389
6,632
40,753
16,492

ALA-1B

3,679
1,489

ALA-1C

15,357
6,215
22,135
8,958

SNM-1A
52
21

14,691
5,945

SNM-1B

3,327
1,346

SNM-1C

1,0214
413
117
48
4,978
2,015

SNM-2A

10,200
4,128

SNM-2B

2,099
849

14,672
5,937
358
145

SNM-2C

3,722
1,506

4,056
1,641

STC-1A

8,384
3,393
19,671
7,961

STC-1B

27,983
11,324

1,746
707

SCZ1

297
120

12,807
5,183

SCZ2
120
49
601
243

3,326
1,346

MER-1

10,153
4,109

2,349
951

MNT-1

525
213

MNT-2
1,233
499
544
220

43,632
17,657

SNB-1

5,418
2,193

8,861
3,586

SNB-2
13
5

9,644
3,903

SNB-3
13,979
5,657

6,070
2,457

SLO-1
176
71

18,011
7,289

SLO-2
19
8

4,602
1,863

SLO-3

524
212

9,972
4,035

SLO-4

52
21

8,097
3,277

SLO-5

511
207

10,269
4,156

SLO-6
840
340

8,989
3,638

SLO-7
2,004
811
4,393
1,778

15,950
6,455

SLO-8
9,443
3,822

6,837
2,767

STB-1
21,181
8,572

3,921
1,587

STB-2

4,922
1,992

STB-3
40,038
16,203

7,394
2,992

STB-4

7,681
3,108
1,011
409

STB-5
1,558
630
1,844
746

9,486
3,839

STB-6
1,867
756
76
31

10,042
4,064

STB-7
32,419
13,120

3,805
1,540

VEN-1
5,300
2,145

1,382
559

VEN-2

2,936
1,188

VEN-3
8,521
3,448

305
124

VEN-4

2,784
1,127

LOS-1
3,907
1,581

321
130

RIV-1

3,002
1,215

7,416
3,001

Total
178,016
72,043
67,052
27,135
48,065
19,451
438,488
177,450
6,291
2,546

Presented below are brief descriptions of all units. The units are listed in order geographically north to south and west to east, with exception of the units in the Sierra foothills which are listed first, north to south.

BUT-1, Hughes Place Pond (5,294 ac (2,142 ha))

This unit is located in east-central Butte County, east of State Highway 70 and west of Oroville-Quincy Highway. BUT-1 is essential for the conservation of the subspecies because the area contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4) and is occupied by the species. This unit encompasses one of five known extant Sierra Foothill populations identified since the time of listing and is located in the eastern most portion of the subspecies historic range. This unit represents the California red-legged frog's adaptation to a wide range of habitat and ecological variability, is known to be occupied, contains high quality habitat, and contains the features essential for the conservation of the subspecies. The unit consists of 1,922 ac (778 ha) of private land, 137 ac (56 ha) of State land and 3,234 ac (1,309 ha) of Federal land and is mapped entirely from occurrence records subsequent to the time of listing. Threats that may require special management in this unit include necessary wildland fire suppression activities which may dewater aquatic habitats resulting in the desiccation of egg masses or direct death of adults from water drafting, timber harvest activities which can alter or remove upland habitat, and predation by nonnative species. We are proposing to exclude 3,234 ac (1,309 ha) of land from the final designation of critical habitat which is managed under the Sierra Nevada Forest Plan by the Plumas National Forest. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Other Land—Exclusions Under Section 4(b)(2) of the Act section below.

YUB-1, Little Oregon Creek (6,322 ac (2,558 ha))

This unit is located in northeastern Yuba County, north of Marysville Road and south of La Porte Road. YUB-1 is considered an area that is essential for the conservation of the subspecies because it contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4) and is occupied by the species. YUB-1 is one of five known extant Sierra Foothill populations identified since the time of listing and is located in the eastern most portion of the subspecies historic range. This unit represents the California red-legged frog's adaptation to a wide range of habitat and ecological variability, is known to be occupied, contains high quality habitat, and contains the features essential for the conservation of the subspecies. This unit consists of 3,833 ac (1,551 ha) of private land and 2,489 ac (1,007 ha) of Federal land and is mapped entirely from occurrence records subsequent to the time of listing. Threats that may require special management in this unit include necessary wildland fire suppression activities which may dewater aquatic habitats resulting in the desiccation of egg masses or direct death of adults from water drafting, timber harvest activities which can alter or remove upland habitat, and predation by nonnative species. We are proposing to exclude 2,489 ac (1,007 ha) of land from the final designation of critical habitat which is managed under the Sierra Nevada Forest Plan by the Plumas National Forest. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Other Land—Exclusions Under Section 4(b)(2) of the Act section below.

NEV-1, Sailor Flat (8,285 ac (3,353 ha))

This unit is located in central Nevada County, approximately three miles (five kilometers) northeast of Nevada City, south of Tyler Foote Road and north of State Highway 20. NEV-1 is considered an area that is essential for the conservation of the subspecies because it contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4) and is occupied by the species. NEV-1 is one of five known extant Sierra Foothill populations and is located in the eastern most portion of the subspecies historic range. This unit represents the California red-legged frog's adaptation to a wide range of habitat and ecological variability, is known to be occupied, contains high quality habitat, and contains the features essential for the conservation of the subspecies. This unit consists of 5,038 ac (2,039 ha) of private land, 90 ac (36 ha) of State land and 3,158 ac (1,278 ha) of Federal land and is mapped entirely from occurrence records subsequent to the time of listing. Threats that may require special management in this unit include timber harvest activities, removal and alteration of habitat due to potential urban development, necessary wildland fire suppression activities which may dewater aquatic habitats resulting in the desiccation of egg masses or direct death of adults from water drafting and predation by nonnative species. We are proposing to exclude 1,512 ac (612 ha) of land from the final designation of critical habitat which is managed under the Sierra Nevada Forest Plan by the Tahoe National Forest. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Other Land—Exclusions Under Section 4(b)(2) of the Act section below.

ELD-1, Spivey Pond (9,254 ac (3,745 ha))

This unit is located in central El Dorado County, south of State Highway 50 and east of Newton Road. ELD-1 is essential for the conservation of the subspecies because it contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), upland habitat for foraging and dispersal activities (PCE 3 and PCE 4), and is occupied by the species. ELD-1 is one of five known extant Sierra Foothill

populations and is located in the eastern most portion of the subspecies historic range. This unit represents the California red-legged frog's adaptation to a wide range of habitat and ecological variability, is known to be occupied, contains high quality habitat, and contains the features essential for the conservation of the subspecies. The unit consists of 8,791 ac (3,558 ha) of private land and 463 ac (188 ha) of Federal land and is mapped entirely from occurrence records subsequent to the time of listing. Threats that may require special management in this unit include necessary wildland fire suppression activities which may dewater aquatic habitats resulting in the desiccation of egg masses or direct death of adults from water drafting, timber harvest activities, and predation by nonnative species. We are proposing to exclude 409 ac (166 ha) of land from the final designation of critical habitat which is managed under the Sierra Nevada Forest Plan by the El Dorado National Forest. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Other Land—Exclusions Under Section 4(b)(2) of the Act section below.

CAL-1, Young's Creek (4,450 ac (1,801 ha))

This unit is located in northwestern Calaveras County, north of State Highway 26 and south of Paloma Road. CAL-1 is essential for the conservation of the subspecies because it contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4) and is occupied by the species. This unit encompasses one of five known extant Sierra Foothill populations identified since the time of listing and is located in the eastern most portion of the subspecies historic range. This unit represents the California red-legged frog's adaptation to a wide range of habitat and ecological variability, is known to be occupied, contains high quality habitat, and contains the features essential for the conservation of the subspecies. The unit consists of 4,442 ac (1,798 ha) of private land and 7 ac (3 ha) of Federal land and is mapped entirely from occurrence records subsequent to the time of listing. The main threats that may require special management in this unit include overgrazing of aquatic and riparian habitats and predation by nonnative species.

NAP-1, Wragg Creek (2,524 ac (1,022 ha))

This unit is located in east-central Napa County and is bisected by State Highway 128 and lies largely to the west of State Highway 121. NAP-1 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). NAP-1 was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies and contains high quality habitat. The unit consists of 2,524 ac (1,022 ha) of private land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include predation by nonnative species.

MRN-1, Salmon Creek (22,559 ac (9,129 ha))

This unit is located in northcentral Marin County, east of State Highway 1 and north of Point Reyes Petaluma Road. MRN-1 is occupied and contains occurrence records subsequent to the time of listing. The area is essential for the conservation for the subspecies because it contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), upland habitat for foraging and dispersal activities (PCE 3 and PCE 4) and is occupied by the species. MRN-1 also provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, and contains high quality habitat. The unit consists of 21,513 ac (8,706 ha) of private land and 1,046 ac (423 ha) of local government land and is mapped from occurrence records subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitats and predation by nonnative species.

SOL-1, Sky Valley (9,245 ac (3,741 ha))

This unit is located in southwestern Solano County and a portion of extreme southeastern Napa County, south of Interstate 80 and west of Interstate 680. SOL-1 contains the following features that are essential for the conservation for the subspecies: aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SOL-1 was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies and contains high quality habitat. The unit consists of 9,245 ac (3,741 ha) of private land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitats, and removal and alteration of habitat due to urbanization.

MRN-2, Point Reyes Peninsula (25,995 ac (10,520 ha))

This unit is located in western Marin County, west of State Highway 1. MRN-2 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). MRN-2 was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies and contains high quality habitat. The unit consists of 25,995 ac (10,520 ha) of Federal land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitats and predation by nonnative species.

CCS-1A, Berkeley Hills (4,205 ac (1,702 ha))

This unit is located in western Contra Costa County, south of Alhambra Valley Road and north of Bear Creek Road. CCS-1A contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). CCS-1A was known to be occupied at time of listing and is currently occupied, contains permanent

and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 730 ac (296 ha) of private land and 3,475 ac (1,406 ha) of local government land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include removal and alteration of habitat due to urbanization, overgrazing of aquatic and riparian habitats, and predation by nonnative species. We are proposing to exclude 3,475 ac (1,406 ha) of land from the final designation of critical habitat which is managed by the East Bay Regional Park District. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Other Land—Exclusions Under Section 4(b)(2) of the Act section below.

CCS-1B, Mulligan Hill (19,734 ac (7,986 ha))

This unit is located in northern Contra Costa County, south of State Highway 4 and north of Marsh Creek Road. CCS-1B contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). CCS-1B was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 16,437 ac (6,652 ha) of private land and 3,297 ac (1,334 ha) of local government land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include removal and alteration of habitat due to urbanization, overgrazing of aquatic and riparian habitats, erosion and siltation due to flooding, and predation by nonnative species. We are proposing to exclude this entire unit from the final designation of critical habitat because it falls within the draft East Contra Costa County Natural Communities Conservation Plan / Habitat Conservation Plan. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Habitat Conservation Plan Lands—Exclusions Under Section 4(b)(2) of the Act section below.

ALA-1A, Los Vaqueros (58,417 ac (23,640 ha))

This unit is located in southeastern Contra Costa and northeastern Alameda Counties, south of Marsh Creek Road and west of the junction of Interstates 205 and 580. ALA-1A contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). ALA-1A was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 40,753 ac (16,492 ha) of private land, 1,276 ac (516 ha) of State land, and 16,389 ac (6,632 ha) of local government land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitat and predation by nonnative species. We are proposing to exclude 18,359 ac (7,430 ha) of land from the final designation of critical habitat because it falls within the draft East Contra Costa County Natural Communities Conservation Plan/Habitat Conservation Plan. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Habitat Conservation Plan Lands—Exclusions Under Section 4(b)(2) of the Act section below.

ALA-1B, San Antonio Creek (3,679 ac (1,489 ha))

This unit is located in north-central Alameda County, north of Interstate 580, west of Livermore Avenue and east of Tassajara Road. ALA-1B contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). ALA-1B is essential for the conservation of the California red-legged frog since the unit is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 3,679 ac (1,489 ha) of private land. Threats that may require special management in this unit include removal and alteration of habitat due to urbanization, overgrazing of aquatic and riparian habitats, and predation by nonnative species.

ALA-1C, San Antonio Reservoir (37,491 ac (15,172 ha))

This unit is located in south central Alameda County, southeast of Vallecitos Road and north of Oakridge Road. ALA-1C contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). ALA-1C was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 22,135 ac (8,958 ha) of private land and 15,357 ac (6,215 ha) of local government land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitats and predation by nonnative species. We are proposing to exclude 15,292 ac (6,189 ha) of land from the final designation of critical habitat which is managed by the East Bay Regional Park District. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Other Land—Exclusions Under Section 4(b)(2) of the Act section below.

SNM-1A, Cahill Ridge (14,743 ac (5,966 ha))

This unit is located in northwestern San Mateo County, west of Interstate 280 and east of U.S. Route 1. SNM-1A contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNM-1A was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides representation of a portion of the geographic range of the subspecies, and

contains high quality habitat. The unit consists of 14,691 ac (5,945 ha) of private land and 52 ac (21 ha) of local government land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include predation by nonnative species.

SNM-2A, Gordon Ridge (10,200 ac (4,128 ha))

This unit is located in west-central San Mateo County, north of La Honda Road and east of U.S. Route 1. SNM-2A contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNM-2A was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations along the coast and inland, provides representation of a portion of the geographic range of the subspecies and contains high quality habitat. This unit consists of 10,200 ac (4,128 ha) of private land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitat and predation by nonnative species.

STC-1A, Cañada de Pala (28,055 ac (11,353 ha))

This unit is located in north-central Santa Clara County, south of Sierra Road and west of Mount Hamilton. STC-1A contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). STC-1A was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations along the coast and inland, provides representation of a portion of the geographic range of the subspecies and contains high quality habitat. This unit consists of 19,671 ac (7,961 ha) of private land, and 8,384 ac (3,393 ha) of local government land and is mapped from occurrence records at the time of listing and subsequent to the time of listing. Threats that may require special management in this unit include removal and alteration of habitat due to urbanization, overgrazing of aquatic and riparian habitats, and predation by nonnative species.

SNM-1B, Langley Hill (3,327 ac (1,346 ha))

This unit is located in east-central San Mateo County, east of La Honda Road and west of State Highway 35. SNM-1B contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNM-1B was known to be occupied at time of listing, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies and contains high quality habitat. The unit consists of 3,327 ac (1,346 ha) of private land and is mapped entirely from occurrence records at time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitat and predation by nonnative species.

SNM-2B, Pescadero Creek (17,129 ac (6,932 ha))

This unit is located in southwestern San Mateo County, south of SNM-2A and north of SNM-2C, east of Highway 1. SNM-2B contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNM-2B was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 14,672 ac (5,937 ha) of private land, 2,099 ac (849 ha) of State land, and 358 ac (145 ha) of military land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitat and predation by nonnative species.

SNM-1C, Peter's Creek (6,117 ac (2,476 ha))

This unit is located in southeastern San Mateo County, west of State Highway 35 and south of SNM-1B. SNM-1C contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SSNM-1C was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies and contains high quality habitat. The unit consists of 4,978 ac (2,015 ha) of private land, 1,021 ac (413 ha) of State land and 117 ac (48 ha) of local government land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitat and predation by nonnative species.

SNM-2C, Año Nuevo (7,777 ac (3,147 ha))

This unit is located in southern San Mateo and extreme northwestern Santa Cruz Counties. SNM-2C contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNM-2C was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 4,056 ac (1,641 ha) of private land and 3,722 ac (1,506 ha) of State land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include predation by nonnative species.

STC-1B, Henry Coe State Park (29,729 ac (12,031 ha))

This unit is located in southeastern Santa Clara County, east of Anderson Lake and north of State Highway 152.

STC-1B contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). STC-1B was known to be occupied at time of listing and is currently occupied, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 1,746 ac (707 ha) of private land and 27,983 ac (11,324 ha) of State land and is mapped from occurrence records at time of listing and subsequent to the time of listing. Threats that may require special management in this unit include predation by nonnative species.

SCZ-1, North Coastal Santa Cruz County (13,104 ac (5,303 ha))

This unit is located along the coastline of Santa Cruz County, from approximately Waddell Creek to Yellow Bank Creek. It includes locations within several watersheds which drain into the Pacific Ocean, and is mapped from occurrence records at time of listing and subsequent to the time of listing. SCZ-1 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SCZ-1 provides connectivity between occupied sites along the coast and further inland. In addition, it contains high quality habitat, indicated by high density of extant occurrences, permanent and ephemeral aquatic habitat suitable for breeding, and accessible upland areas for dispersal, shelter and food. The unit consists of 12,807 ac (5,183 ha) of private land, and 297 ac (120 ha) of State land. Threats that may require special management in this unit include water diversions which could dewater portions of aquatic habitat leading to desiccation of egg masses or temporal loss of aquatic habitat. We are proposing to exclude 4.9 ac (2 ha) of land from the final designation of critical habitat which is managed under the Bonny Doon Habitat Conservation Plan. For a further discussion of this proposed exclusion see the Relationship of Critical Habitat to Habitat Conservation Plan Lands—Exclusions Under Section 4(b)(2) of the Act section below.

MER-1, Pacheco Pass (12,502 ac (5,059 ha))

This unit is located in southwestern Merced County and a small portion of southeastern Santa Clara County, west of San Luis Reservoir. MER-1 is essential for the conservation of the subspecies because it contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4), and is occupied by the species. MER-1 is an area determined to be occupied since the time of listing and is currently occupied, provides for connectivity between populations, provides representation of a portion of the geographic range of the subspecies, and contains high quality habitat. The unit consists of 2,349 ac (951 ha) of private land and 10,153 ac (4,109 ha) of State land and is mapped entirely from occurrence records subsequent to time of listing. Threats that may require special management in this unit include overgrazing of aquatic and riparian habitat and predation by nonnative species.

SCZ-2, Watsonville Slough (4,046 ac (1,637 ha))

This unit is located along the coastal plain in southern Santa Cruz County, north of the mouth of the Pajaro River and seaward of California Highway 1. It includes locations in the Watsonville Slough system, including all or portions of Gallighan, Hanson, Harkins, Watsonville, Struve, and the West Branch of Struve Sloughs. The unit is mapped from occurrence records at time of listing and subsequent to the time of listing. SCZ-2 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SCZ-2 provides connectivity between occupied sites along the coast and further inland. In addition, it contains permanent and ephemeral aquatic habitats suitable for breeding, and upland areas for dispersal, shelter and food. The unit consists of 3,326 ac (1,346 ha) of private land, 601 ac (243 ha) of State land, and 120 ac (49 ha) of Federal land. Threats that may require special management in this unit include mortality due to agricultural pollution, conversion of habitat by introduced invasive plants, removal and alteration of aquatic and upland habitat due to urbanization and predation by nonnative species.

MNT-1, Elkhorn Slough (525 ac (213 ha))

This unit is located along the coastal plain in northern Monterey County inland from the town of Moss Landing, and is mapped from occurrence records at time of listing and subsequent to the time of listing. MNT-1 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). MNT-1 provides connectivity from the coastal plain and outer Coast Ranges to the inner Coast Ranges, contains permanent and ephemeral aquatic habitats suitable for breeding, contains upland areas for dispersal, shelter and food which we have determined are essential to the conservation of the subspecies. Elkhorn Slough is unique in that it is a large estuary/freshwater slough system not typically found on the California coast. The unit consists of 525 ac (213 ha) of State land. Threats that may require special management in this unit include mortality due to agricultural pollution, trematode infestation and chytrid fungus infection, and predation by nonnative species.

SNB-1, Hollister Hills (14, 279 ac (5,779 ha))

This unit is located in northwestern San Benito County in the foothills of the Gabilan Range. It is mapped from occurrence records at time of listing and subsequent to the time of listing near Saint Frances Retreat, San Juan Oaks, Azalea Canyon, Bird Creek, and the Hollister Hills State Vehicle Recreation Area. SNB-1 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNB-1 is occupied by the species and provides connectivity between sites between the coast plain and inner Coast Ranges, and contains permanent and ephemeral aquatic habitats suitable for breeding, and accessible upland areas for dispersal, shelter and food. The unit consists of 8,861 ac (3,586 ha) of private land, and 5,418 ac (2,193 ha) of State land. Threats that may require special management in this unit include removal and alteration of aquatic and upland habitat due to recreational and residential development, off-road vehicular activities, and predation by nonnative species.

SNB-2, Paicines Reservoir and Tres Pinos Creek (9,657 ac (3,908 ha))

This unit is located in northwestern San Benito County, approximately 8 mi (13 km) southeast of the City of Hollister and is mapped from occurrence records subsequent to listing in and near Paicines Reservoir and Tres Pinos Creek. SNB-2 is considered an area that is essential for the conservation of the subspecies. The area contains aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2), and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNB-2 is essential to the conservation of the subspecies because it provides connectivity between sites on the coast plain and inner Coast Range, it contains permanent and ephemeral aquatic habitats suitable for breeding, and upland areas for dispersal, shelter and food. The unit consists of 9,644 ac (3,903 ha) of private land, and 13 ac (5 ha) of Federal land. Threats that may require special management in this unit include removal and alteration of aquatic and upland habitat due to urbanization and predation by nonnative species.

MNT-2, Carmel River (45, 408 ac (18,376 ha))

This unit is located about 3 mi (5 km) south to about 22 mi (35 km) southeast of the city of Monterey and includes locations in the Carmel River Valley and nearby San Jose Creek. It is mapped from occurrence records at time of listing and subsequent to the time of listing at the Carmel River, and at Las Garzas, San Jose, and San Clemente creeks. MNT-2 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). MNT-2 is occupied by the species and contains permanent and ephemeral aquatic habitats suitable for breeding, contains sufficient PCEs to support behaviors we have determined are essential to the conservation of the subspecies, and accessible upland areas for dispersal, shelter and food. The unit consists of 43, 632 ac (17,657 ha) of private land, 544 ac (220 ha) of State land, and 1,233 ac (499 ha) of Federal land. Threats that may require special management in this unit include removal and alteration of aquatic and upland habitat due to urbanization, dewatering of aquatic habitat due to water pumping and water diversions, reservoir maintenance activities, and predation by nonnative species.

SNB-3, Pinnacles National Monument (20,049 ac (8,114 ha))

This unit is located in the Gabilan Range at Pinnacles National Monument, about 3.5 mi (5.6 km) west of the town of San Benito, in southern San Benito County, and is mapped from occurrence records at time of listing and subsequent to the time of listing. SNB-3 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SNB-3 provides connectivity between sites between the coast plain and inner Coast Ranges, and contains permanent and ephemeral aquatic habitat suitable for breeding, and accessible upland areas for dispersal, shelter and food, and is occupied by the species. The unit consists of 6,070 ac (2,457 ha) of private land and 13,979 ac (5,657 ha) of Federal land. Threats that may require special management in this unit include overgrazing and trampling of aquatic and upland habitat by feral pigs, recreational activities, and predation by nonnative species.

SLO-1, Cholame (18,187 ac (7,360 ha))

This unit is located in northeastern San Luis Obispo and northwestern Kern Counties, includes locations in the Cholame Creek watershed, and is mapped from occurrence records at time of listing and subsequent to the time of listing. SLO-1 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SLO-1 contains permanent and ephemeral aquatic habitats suitable for breeding, and contains accessible upland areas for dispersal, shelter and food, and is occupied by the species. The unit consists of 18,011 ac (7,289 ha) of private land, and 176 ac (71 ha) of Federal land. Threats that may require special management in this unit include highway construction which may remove upland or aquatic habitat, overgrazing of aquatic and riparian habitats, and dewatering of aquatic habitats due to water diversions.

SLO-2, Piedras Blancas (4,621 ac (1,870 ha))

This unit is located along the coast in northwestern San Luis Obispo County, extends from Arroyo de Los Chinos south to Point Piedras Blancas, and is mapped from occurrence records at time of listing. SLO-2 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SLO-2 provides connectivity within the Santa Lucia Range, and between this range and the inner Coast Ranges in San Luis Obispo County, and is occupied by the species. The unit contains high quality habitat, indicated by high density of extant occurrences, permanent and ephemeral aquatic habitats suitable for breeding, and accessible upland areas for dispersal, shelter and food. The unit consists of 4,602 ac (1,863 ha) of private land, and 19 ac (8 ha) of Federal land. Threats that may require special management in this unit include dewatering of aquatic habitats due to water diversion and predation by nonnative species.

SLO-3, San Simeon (10,496 ac (4,248 ha))

This unit is located along the coast in northwestern San Luis Obispo County, extends from Arroyo del Puerto south to San Simeon Creek, and is mapped from occurrence records at time of listing and subsequent to the time of listing. SLO-3 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SLO-3 provides connectivity within the Santa Lucia Range, and between this range and the inner Coast Ranges in San Luis Obispo County, and contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food which we have determined are essential to the conservation of the subspecies, and is occupied by the species. The unit consists of 9,972 ac (4,035 ha) of private land and 524 ac (212 ha) of State land. Threats that may require special management in this unit include dewatering of aquatic habitats due to water diversion, overgrazing of aquatic and riparian habitats, and predation by nonnative species.

SLO-4, Santa Rosa Creek (8,150 ac (3,298 ha))

This unit is located along the coast in northwestern San Luis Obispo County and is mapped from occurrence records at the time of listing and subsequent to time of listing. SLO-4 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and

dispersal activities (PCE 3 and PCE 4). SLO-4 provides connectivity within the Santa Lucia Range, and between this range and the inner Coast Ranges in San Luis Obispo County, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas for dispersal, shelter and food and is occupied by the species. This unit consists of 8,097 ac (3,277 ha) of private land, and 52 ac (21 ha) of State land. Threats that may require special management in this unit include dewatering of aquatic habitats due to water diversion, overgrazing of aquatic and riparian habitats, and predation by nonnative species.

SLO-5, Point Estero to Cayucos Creek (10,780 ac (4,363 ha))

This unit is located along the coast in central San Luis Obispo County, west of the town of Cayucos, and is mapped from occurrence records at time of listing and subsequent to the time of listing. SLO-5 contains the following features that are essential for the conservation for the subspecies: Aquatic habitat for breeding and non-breeding activities (PCE 1 and PCE 2) and upland habitat for foraging and dispersal activities (PCE 3 and PCE 4). SLO-5 provides connectivity within the Santa Lucia Range, and between this range and the inner Coast Ranges in San Luis Obispo County, contains permanent and ephemeral aquatic habitats suitable for breeding, upland areas

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A05-21594. Public record. Not legal advice.