Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the San Bernardino Kangaroo Rat (Dipodomys merriami parvus), 33808-33842 [07-2823]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 72, Number 117 (Tuesday, June 19, 2007)]
[Proposed Rules]
[Pages 33808-33842]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 07-2823]



[[Page 33807]]

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Part II





Department of the Interior





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Fish and Wildlife Service



50 CFR Part 17



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Endangered and Threatened Wildlife and Plants; Revised Critical Habitat 
for the San Bernardino Kangaroo Rat (Dipodomys merriami parvus); 
Proposed Rule

Federal Register / Vol. 72, No. 117 / Tuesday, June 19, 2007 / 
Proposed Rules

[[Page 33808]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AV07


Endangered and Threatened Wildlife and Plants; Revised Critical 
Habitat for the San Bernardino Kangaroo Rat (Dipodomys merriami parvus)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
revise currently designated critical habitat for the San Bernardino 
kangaroo rat (Dipodomys merriami parvus) under the Endangered Species 
Act of 1973, as amended (Act). Currently, approximately 33,295 acres 
(ac) (13,485 hectares (ha)) are designated as critical habitat for the 
San Bernardino kangaroo rat in San Bernardino and Riverside counties, 
California. Under this proposal, approximately 9,079 ac (3,674 ha) of 
land located in San Bernardino and Riverside counties, California would 
fall within the boundaries of the revised critical habitat designation. 
Further, of the 9,079 ac of revised critical habitat, we are proposing 
to exclude 2,544 ac (1,029 ha) of land covered by the Woolly-Star 
Preserve Area Management Plans, the Former Norton Air Force Base 
Conservation Management Plan, the Cajon Creek Habitat Conservation 
Management Area Habitat Enhancement and Management Plan, and the 
Western Riverside County Multiple Species Habitat Conservation Plan 
from the final designation under section 4(b)(2) of the Act.

DATES: We will accept comments from all interested parties until August 
20, 2007. We must receive requests for public hearings, in writing, at 
the address shown in the ADDRESSES section by August 3, 2007.

ADDRESSES: If you wish to comment, you may submit your comments and 
materials concerning this proposal by any one of several methods:
    1. You may mail or hand-deliver your written comments and 
information to Jim Bartel, Field Supervisor, U.S. Fish and Wildlife 
Service, Carlsbad Fish and Wildlife Office, 6010 Hidden Valley Road, 
Carlsbad, CA 92011.
    2. You may send comments by electronic mail (e-mail) to 
fw8cfwocomments@fws.gov. Please include ``Attn: San Bernardino kangaroo 
rat'' in your e-mail subject header. If you do not receive a 
confirmation from the system that we have received your message, 
contact us directly by calling our Carlsbad Fish and Wildlife Office at 
760-431-9440.
    3. You may fax your comments to Jim Bartel, Field Supervisor, 
Carlsbad Fish and Wildlife Office at 760-431-5901.
    4. You may go to the Federal eRulemaking Portal: https://
www.regulations.gov. Follow the instructions for submitting comments.
    Comments and materials received, as well as supporting 
documentation used in the preparation of this proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at the Carlsbad Fish and Wildlife Office, 6010 Hidden Valley 
Road, Carlsbad, CA 92011 (telephone 760-431-9440).

FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor, Carlsbad 
Fish and Wildlife Office, 6010 Hidden Valley Road, Carlsbad, CA 92011; 
telephone 760-431-9440; facsimile 760-431-5901. Persons who use a 
telecommunications device for the deaf (TDD) may call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

    We intend that any final action resulting from this proposal to 
revise critical habitat for the San Bernardino kangaroo rat will be as 
accurate and as effective as possible. Therefore, comments or 
suggestions from the public, other concerned governmental agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) The reasons why habitat should or should not be designated as 
critical habitat under section 4 of the Act (16 U.S.C. 1531 et seq.), 
including whether there are areas we previously designated, but are not 
proposing for designation here, that should be designated as critical 
habitat;
    (2) Specific information on the amount and distribution of San 
Bernardino kangaroo rat habitat; what areas occupied at the time of 
listing and that contain features essential for the conservation of the 
subspecies should be included in the designation and why; and what 
areas that were not occupied at the time of listing are essential to 
the conservation of the subspecies and why;
    (3) Specific information on dispersal areas important for habitat 
connectivity, their role in the conservation and recovery of the 
subspecies, and reasons why such areas should or should not be included 
in the critical habitat designation;
    (4) Our proposed exclusions totaling 2,544 ac (1,029 ha) of San 
Bernardino kangaroo rat habitat and whether the benefits of excluding 
these areas would outweigh the benefits of their inclusion under 
section 4(b)(2) of the Act (see Exclusions Under Section 4(b)(2) of the 
Act section for a detailed discussion). If the Secretary determines 
that the benefits of including these lands would outweigh the benefits 
of excluding them, they will not be excluded from final critical 
habitat;
    (5) Any proposed critical habitat areas covered by existing or 
proposed conservation or management plans that we should consider for 
exclusion from the final designation under section 4(b)(2) of the Act. 
We specifically request information on any operative or draft habitat 
conservation plans for the San Bernadino kangaroo rat that have been 
prepared under section 10(a)(1)(B) of the Act, as well as any other 
management or conservation plan or agreement that benefits the kangaroo 
rat or its primary constituent elements;
    (6) Specific information regarding the current status of plan 
implementation for the following management plans: the Woolly-Star 
Preserve Area Management Plans; the Former Norton Air Force Base CMP; 
the Cajon Creek Habitat Conservation Management Area HEMP; and Western 
Riverside MSHCP;
    (7) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed revised critical 
habitat;
    (8) Any foreseeable economic, national security, or other potential 
impacts resulting from the proposed revised designation and, in 
particular, any impacts on small entities, and the benefits of 
including or excluding areas that exhibit these impacts; and
    (9) Whether our approach to designating critical habitat could be 
improved or modified in any way as to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concerns and comments.
    You may submit your comments and materials concerning this proposal 
by any one of several methods (see ADDRESSES section). Please note that 
comments must be received by the date specified in the DATES section in 
order to be considered and that the e-mail address 
fw8cfwocomments@fws.gov will be closed out at the termination of the 
public comment period.
    Before including your address, phone number, e-mail address, or 
other personal identifying information in your comment, you should be 
aware that your entire comment--including your personal identifying 
information--may

[[Page 33809]]

be made publicly available at any time. While you may ask us to 
withhold your personal identifying information from public review, we 
cannot guarantee that we will be able to do so.

Background

    It is our intent to discuss only those topics directly relevant to 
the revision of designated critical habitat for the San Bernardino 
kangaroo rat in this proposed rule. For more information on the biology 
and ecology of the San Bernardino kangaroo rat, refer to the final 
listing rule published in the Federal Register on September 24, 1998 
(63 FR 51005), and the proposed and final critical habitat rules 
published in the Federal Register on December 8, 2000, and April 23, 
2002, respectively (65 FR 77178 and 67 FR 19812).

Species Description

    The San Bernardino kangaroo rat is one of the most highly 
differentiated of 19 recognized subspecies of Merriam's kangaroo rat 
(Dipodomys merriami). The subspecies occurs primarily on alluvial fans 
with appropriate physical and vegetative characteristics in San 
Bernardino and Riverside counties, California (Hall 1981, p. 586; 
Lidicker 1960, p. 190; Williams et al. 1993, p. 62).

Species Distribution

    The historical range of the San Bernardino kangaroo rat extends 
from the San Bernardino Valley in San Bernardino County to the Menifee 
Valley in Riverside County (Hall and Kelson 1959, p. 532; Lidicker 
1960, p. 190). From the early 1880s to the early 1930s, the subspecies 
was a common resident of the San Bernardino and San Jacinto Valleys of 
southern California (Lidicker 1960, p. 190). Prior to 1960, the San 
Bernardino kangaroo rat was known from more than 25 localities within 
this range (McKernan 1997, p. 3; McKernan 1993, p. 36). Based on the 
distribution of apparent suitable soils and museum collections, the 
Service estimated at the time of emergency listing in 1998 that the 
historical range of the subspecies encompassed approximately 326,467 ac 
(130,587 ha) (63 FR 51005, September 24, 1998). Recent studies indicate 
that the San Bernardino kangaroo rat occupies a wider range of soil and 
vegetation types than was previously thought (Braden and McKernan 2000, 
p. 17), which suggests that the subspecies' historical range may have 
been larger than previously estimated at the time of listing. However, 
only portions of the historical range would have been occupied at any 
given time due to the dynamic nature of alluvial habitat and resultant 
variation in habitat suitability.
    At the time of emergency listing in 1998, the extant range of the 
San Bernardino kangaroo rat was thought to encompass approximately 
3,247 ac (1,299 ha) of suitable habitat divided unequally among seven 
geographically distinct locations (63 FR 3835, January 27, 1998; 
McKernan 1997, p. 11). The extent of occupied habitat within San 
Bernardino County included 1,725 ac (690 ha) within the Santa Ana 
River, 20 ac (8 ha) in City Creek, 1,140 ac (456 ha) in Lytle and Cajon 
creeks, 5 ac (2 ha) within Etiwanda Creek, 5 ac (2 ha) in Reche Canyon, 
and 2 ac (0.8 ha) in South Bloomington. San Bernardino kangaroo rat 
distribution within Riverside County was limited to 350 acres (140 ha) 
within the San Jacinto River (McKernan 1997 as cited in 63 FR 3836). 
This determination was based upon the then-current understanding of 
what constituted suitable habitat for the subspecies and an evaluation 
of landscape-scale changes (e.g., dams, flood-control channels, water 
diversions, roadway construction) that had altered the fluvial 
processes and/or habitat for this subspecies. Subsequently, we 
evaluated new information and the results of live-trapping that 
documented the occurrence of the San Bernardino kangaroo rat within 
mature alluvial fan sage scrub habitat (sensu Smith 1980 and Hanes et 
al. 1989). As a result, in the final rule to list the subspecies, we 
estimated the extant range of the San Bernardino kangaroo rat to 
encompass approximately 9,797 ac (3,919 ha) of suitable habitat within 
the Santa Ana River, Lytle and Cajon creeks, and the San Jacinto River 
(63 FR 51005, September 24, 1998).
    When the final rule designating critical habitat for the San 
Bernardino kangaroo rat was published in 2002 (67 FR 19812, April 23, 
2002), the rule reported that the designated critical habitat area is 
33,295 ac (13,485 ha). However, the total area for each of the four 
critical habitat units given in that rule add up to 33,290 ac (13,480 
ha) and we recognize this total as the existing critical habitat area 
in this revised rule. At the time of publication of the final critical 
habitat rule, research indicated that San Bernardino kangaroo rats can 
occupy mature alluvial sage scrub, coastal sage scrub, and even 
chaparral vegetation types (Braden and McKernan 2000, p. 16). Thus, 
within the 33,290 ac (13,480 ha) designated as critical habitat in 
2002, approximately 32,480 ac (13,155 ha) were believed to be occupied 
by the subspecies (67 FR 19812). In the final designation, we stated 
that systematic and general biological surveys resulted in the 
documentation of additional occurrences within and outside of areas 
previously known to be occupied by the subspecies and that based on 
this information, the San Bernardino kangaroo rat occupied a larger 
area than was known at the time of listing. However, since these 
additional occurrences are within the general areas described as 
occupied in the listing rule (Santa Ana River wash, Lytle and Cajon 
washes, and the San Jacinto River wash and adjacent upland areas), we 
consider the areas supporting these occurrences to have been occupied 
at the time of listing.
    New occurrences of San Bernardino kangaroo rat have also been found 
since the final critical habitat designation in 2002. These occurrences 
are also within the general areas of the Santa Ana River wash, Lytle 
and Cajon washes, and San Jacinto River wash that were known to be 
occupied at the time of listing and known to be occupied at the time of 
the final critical habitat rule. Therefore, we consider the areas 
supporting these new occurrences to have been occupied at the time of 
listing.

Previous Federal Actions

    On March 30, 2005, the Pacific Legal Foundation filed suit against 
the Service challenging our failure to provide adequate delineation, 
justification, or sufficient analysis of economic and other impacts in 
the designation of critical habitat for the San Bernardino kangaroo rat 
and 26 other species. On March 23, 2006, a settlement agreement was 
reached requiring the Service to propose to revise critical habitat for 
the San Bernardino kangaroo rat as appropriate. The settlement 
stipulated that on or before June 1, 2007, the Service shall submit for 
publication in the Federal Register a proposed rule regarding any 
revisions to the designation of critical habitat, and that a final rule 
shall be submitted for publication in the Federal Register on or before 
June 1, 2008. For more information on previous Federal actions 
concerning the San Bernardino kangaroo rat, refer to the final listing 
rule published in the Federal Register on September 24, 1998 (63 FR 
51005), and the final designation of critical habitat published in the 
Federal Register on April 23, 2002 (67 FR 19812).

Critical Habitat

    Critical habitat is defined in section 3 of the Act as (i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in

[[Page 33810]]

accordance with the Act, on which are found those physical or 
biological features (I) essential to the conservation of the species 
and (II) that may require special management considerations or 
protection; and (ii) specific areas outside the geographical area 
occupied by a species at the time it is listed, upon a determination 
that such areas are essential for the conservation of the species. 
Conservation, as defined under section 3 of the Act, means to use and 
the use of all methods and procedures that are necessary to bring any 
endangered species or threatened species to the point at which the 
measures provided under the Act are no longer necessary. Such methods 
and procedures include, but are not limited to, all activities 
associated with scientific resources management such as research, 
census, law enforcement, habitat acquisition and maintenance, 
propagation, live trapping, and transplantation, and, in the 
extraordinary case where population pressures within a given ecosystem 
cannot be otherwise relieved, may include regulated taking.
    Critical habitat receives protection under section 7(a)(2) 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(a)(2) of the Act requires 
consultation on Federal actions that are likely to result in the 
destruction or adverse modification of critical habitat. The 
designation of critical habitat does not affect land ownership or 
establish a refuge, wilderness, reserve, preserve, or other 
conservation area. Such designation does not allow government or public 
access to private lands. Section 7(a)(2) of the Act is a purely 
protective measure and does not require implementation of restoration, 
recovery, or enhancement measures.
    To be included in a critical habitat designation, the habitat 
within the area occupied by the species at the time of listing must 
first have features that are essential to the conservation of the 
species. Critical habitat designations identify, to the extent known 
using the best scientific data available, habitat areas that provide 
essential life cycle needs of the species (i.e., areas on which are 
found the primary constituent elements, as defined at 50 CFR 
424.12(b)).
    Habitat 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 considerations 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 under section 4(b)(2) of the Act.) Furthermore, when 
the best available scientific data do not demonstrate that the 
conservation needs of the species require additional areas, we will not 
designate critical habitat in areas outside the geographical area 
occupied by the species at the time of listing. However, an area 
currently occupied by the species, but not occupied at the time of 
listing, will likely, but not always, be essential to the conservation 
of the species, and therefore, may be included in the critical habitat 
designation.
    The Service's 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 decisions made by the Service represent the best scientific data 
available. They require Service biologists to the extent consistent 
with the Act and with the use of the best scientific data available, to 
use primary and original sources of information as the basis for 
recommendations to designate critical habitat. When determining which 
areas are critical habitat, a primary source of information is 
generally the listing package for the species. Additional information 
sources may 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 
and make revisions thereto on the basis of the best scientific data 
available. 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 habitat areas eventually 
determined necessary for the recovery of the species. For these 
reasons, critical habitat designations do not imply that habitat 
outside the designation is unimportant or may not be required for 
recovery.
    Areas that support populations of the San Bernardino kangaroo rat, 
but are outside the critical habitat designation, will continue to be 
subject to conservation actions implemented under section 7(a)(1) of 
the Act and to the regulatory protections afforded by the section 
7(a)(2) jeopardy standard, as determined on the basis of the best 
available information at the time of the action. Federally funded or 
permitted projects affecting listed species outside their designated 
critical habitat areas may still result in jeopardy findings in some 
cases. Similarly, critical habitat designations made on the basis of 
the best available information at the time of designation will not 
control the direction and substance of future recovery plans, habitat 
conservation plans, or other species conservation planning efforts if 
new information available to these planning efforts calls for a 
different outcome.

Methods

    As required by section 4(b) of the Act, we used the best scientific 
and commercial data available in determining areas occupied at the time 
of listing that contain features essential to the conservation of the 
San Bernardino kangaroo rat, and areas unoccupied at the time of 
listing that are essential to the conservation of the subspecies, or 
both. We have also reviewed available information pertaining to the 
habitat requirements of this subspecies. These data included: research 
and survey observations published in peer reviewed articles; regional 
Geographic Information System (GIS) coverages; Riverside County 
Multiple Species Habitat Conservation Program (MSHCP) database; the 
University of California, Riverside, species database; the California 
Natural Diversity Database; and data from reports submitted by 
biologists holding section 10(a)(1)(A) recovery permits, including 
results from ongoing research on the San Bernardino kangaroo rat by the 
San Bernardino County Museum. We are not currently proposing any areas 
outside the geographical area presently occupied by the subspecies.

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas to propose as critical 
habitat within areas occupied by the species at the time of listing, we 
consider those physical and biological features (primary constituent 
elements) that are essential to the

[[Page 33811]]

conservation of the subspecies and that may require special management 
considerations or protection. These include, but are not limited to: 
(1) Space for individual and population growth and for normal behavior; 
(2) food, water, air, light, minerals, or other nutritional or 
physiological requirements; (3) cover or shelter; (4) sites for 
breeding, reproduction, and rearing (or development) of offspring; and 
(5) habitats that are protected from disturbance or are representative 
of the historic, geographical, and ecological distributions of a 
species.
    The specific primary constituent elements (PCEs) required for the 
San Bernardino kangaroo rat are derived from the biological needs of 
the San Bernardino kangaroo rat as described below.

Space for Individual and Population Growth and Normal Behavior

    San Bernardino kangaroo rats are typically found on alluvial fans, 
which are relatively flat or gently sloping masses of loose rock, 
gravel, and sand deposited by a stream as it flows into a valley or 
upon a plain (McKernan 1993, p. 1). This subspecies is also found on 
floodplains, washes, areas with braided channels, and in adjacent 
upland areas containing appropriate physical and vegetative 
characteristics (McKernan 1993, p. 1). These areas consist of sand, 
loam, sandy loam, or gravelly soils (McKernan 1993, p. 1) that are 
associated with alluvial processes (i.e., the scour and deposition of 
clay, silt, sand, gravel, or similar material by running water such as 
rivers and streams; or debris flows). San Bernardino kangaroo rats have 
a strong preference for, and are more abundant on, soils deposited by 
alluvial processes (McKernan 1997, p. 36). These soils allow San 
Bernardino kangaroo rats to dig simple, shallow burrow systems for 
shelter and rearing offspring, and surface pits for food storage that 
provide for individual and population growth and for normal behavior of 
this subspecies.
    Few studies have been conducted on the burrowing behavior of the 
San Bernardino kangaroo rat; however, their burrowing habits are 
similar to the Merriam's kangaroo rat (of which the San Bernardino 
kangaroo rat is a subspecies) which has been extensively studied. 
Merriam's kangaroo rats have weak forelegs and are poor diggers; as a 
result, they dig simple shallow burrow systems where they spend 
approximately 75 percent of their lives (Reynolds 1958, pp. 113 and 
122). Burrows consist of one or two chambers and average 6 inches in 
depth (Reynolds 1960, p. 51). Kenagy (1973, p. 1207) observed that 
Merriam's kangaroo rats occupied one to three simple burrows depending 
on the season. Merriam's kangaroo rats do not have the ability to 
burrow into hard soils, and because of this, the highest numbers of 
kangaroo rats can be found on loose, sandy soils (Reynolds 1958, p. 
113; Huey 1951, p. 212). Light, textured soil that is favorable to 
burrowing is an important factor limiting the range of Merriam's 
kangaroo rats (Reynolds 1958, p. 114). Sandy loam soils are not too 
heavy to discourage digging, yet they are not light enough to 
facilitate tunnel cave-ins that can occur in other soil types (Reynolds 
1958, p. 113). For these reasons, sandy loam soils found on alluvial 
fans and maintained by alluvial processes are crucial to the survival 
and normal behavior of the San Bernardino kangaroo rat.
    Alluvial sage scrub habitat is necessary for normal behavior of the 
San Bernardino kangaroo rat because this plant community provides cover 
and food resources within areas containing suitable soils for 
burrowing. Alluvial sage scrub is considered a distinct and rare plant 
community that dominates major outwash fans at the mouths of canyons 
along the coastal side of the San Gabriel, San Bernardino, and San 
Jacinto Mountains and some smaller floodplain and riverine areas of 
southern California (Hanes et al. 1989, p. 187). Described as a variant 
of coastal sage scrub (Smith 1980, p. 135), alluvial sage scrub is also 
referred to as alluvial scrub, Riversidean alluvial fan scrub, alluvial 
fan sage scrub, cismontane alluvial scrub, alluvial fan scrub, or 
Riversidean alluvial fan sage scrub. Alluvial sage scrub occurs on two 
types of floodplain soils, Riverwash Association soils and Soboba 
Association soils (Hanes et al. 1989, p. 188). Comprised of an 
assortment of low growing drought-deciduous shrubs, larger evergreen 
woody shrubs, and other perennial species tolerant of a relatively 
sterile, rapidly draining substrate, this relatively open vegetation 
type is adapted to periodic severe flooding and erosion (Hanes et al. 
1989, p. 187; Smith 1980, p. 126).
    Alluvial sage scrub vegetation includes plant species that are 
often associated with coastal sage scrub, chaparral, or desert 
transition communities (Smith 1980, p. 126). Common plant species found 
within these plant communities may include: Lepidospartum squamatum 
(scalebroom), Eriogonum fasciculatum (California buckwheat), 
Eriodictyon crassifolium (woolly yerba santa), Eriodictyon trichocalyx 
(hairy yerba santa), Yucca whipplei (our Lord's candle), Rhus ovata 
(sugar bush), Rhus integrifolia (lemonadeberry), Malosma laurina 
(laurel sumac), Juniperus californicus (California juniper), Baccharis 
salicifolia (mulefat), Penstemon spectabilis (showy penstemon), 
Heterotheca villosa (golden aster), Eriogonum elongatum (tall 
buckwheat), Encelia farinosa (brittle bush), Opuntia spp. (prickly pear 
and cholla), Adenostoma fasciculatum (chamise), Prunus ilicifolia 
(holly-leaf cherry), Quercus spp. (oaks), Salvia apiana (white sage), 
annual forbs (e.g., Phacelia spp. (phacelia), Lupinus spp. (lupine), 
and Plagiobothrys spp. (popcorn flower)), and native and nonnative 
grasses.
    Three phases of alluvial sage scrub have been described: pioneer, 
intermediate, and mature. The phases are thought to correspond to 
factors such as flood scour, distance from flood channel, time since 
last flood, and substrate features (Smith 1980, p. 136; Hanes et al. 
1989, p. 187). Under natural conditions, flood waters periodically 
break out of the main river channel in a complex pattern, resulting in 
a braided appearance to the floodplain and a mosaic of vegetation 
stages. Pioneer sage scrub, the earliest phase, is subject to frequent 
hydrological disturbance and the sparse vegetation pattern is usually 
renewed by frequent floods (Smith 1980, p. 136; Hanes et al. 1989, p. 
187). The intermediate phase, which is typically found on benches 
between the active channel and mature floodplain terraces, is subject 
to periodic flooding at longer intervals. The vegetation of early and 
intermediate stages is relatively open (less than 50 percent canopy 
cover) and supports the highest densities of the San Bernardino 
kangaroo rat (McKernan 1997, p. 50), likely due in part to few root 
systems to interfere with burrowing. Areas like these, with a 
significant amount of bare ground, can also facilitate movement for a 
bipedal species like the San Bernardino kangaroo rat. For Merriam's 
kangaroo rats, an abundance of perennial grass cover can create an 
unfavorable environment by interfering with ease of travel and escape 
from predators (Reynolds 1958, p. 114).
    The oldest, or mature phase of alluvial sage scrub, which is found 
on elevated floodplain terraces, is rarely affected by flooding and 
supports the highest plant density (Smith 1980, p. 137). Although 
mature areas are generally used less frequently or occupied at lower 
densities by San Bernardino kangaroo rats (likely due to extensive root 
systems and heavy vegetative cover that inhibit burrowing

[[Page 33812]]

and predator escape) than those supporting earlier phases, these areas 
are essential for the conservation of the subspecies. Lower portions of 
the floodplain, where higher densities of San Bernardino kangaroo rats 
are found, are likely to become inundated or lost due to scour and 
sediment deposition during flooding events, and some animals may drown 
during the event. In a study to determine the effects of flooding on 
Merriam's kangaroo rats and two other heteromyid (family of rodents 
that includes the kangaroo rats, kangaroo mice, and pocket mice) 
species, Kenagy (1973, p. 1205) noted heavy burrow damage, and a 23 
percent reduction in the number of chisel-toothed kangaroo rats 
(Dipodomys microps) trapped compared to pre-flood numbers. Elevated 
upland portions of the floodplain containing mature phase alluvial sage 
scrub with patches of suitable soils and vegetative cover can support 
some individuals, but the low density of animals suggests these areas 
likely remain occupied only because of their proximity to the more 
densely occupied lower elevation portions of the floodplain. More 
importantly for the preservation of the subspecies in channelized 
systems where bank-to-bank flooding can occur, individuals occupying 
the upland areas may be the only San Bernardino kangaroo rats remaining 
for recolonization of the lower floodplain after flooding has subsided 
(Pavelka 2006). Research conducted by Braden and McKernan (2000, p. 16) 
during 1998 and 1999 demonstrated that areas with late phases of 
floodplain vegetation, such as mature alluvial fan sage scrub and 
associated coastal sage scrub and chaparral, including some areas of 
moderate to dense vegetation such as nonnative grasslands, are at least 
periodically occupied by the subspecies. Due to the dynamic nature of 
the alluvial floodplain, all elevations within the floodplain and the 
associated phases of alluvial sage scrub habitat are essential to the 
conservation and long-term survival of the San Bernardino kangaroo rat.
    A limited amount of data exists pertaining to population dynamics 
of the San Bernardino kangaroo rat. Information is not currently 
available on several aspects of the subspecies' life history such as 
fecundity (the capacity of an organism to produce offspring), survival, 
population age and sex structure, intra- and interspecific competition, 
and causes and rates of mortality. With respect to population density, 
Braden and McKernan (2000) documented substantial annual variation on a 
trapping grid in San Bernardino County, where densities ranged from 2 
to 26 animals per ha (2.47 ac). The reasons for these greatly disparate 
values during the 15-month study are unknown. These fluctuations bring 
to light several important aspects of the subspecies' distribution and 
life history which should be considered when identifying areas 
essential for the conservation of the subspecies: (1) A low population 
density observed in an area at one point in time does not mean the area 
is occupied at the same low density during any other month, season, or 
year; (2) a low population density is not an indicator of low habitat 
quality or low overall value of the land for the conservation of the 
subspecies; (3) an abundance of San Bernardino kangaroo rats can 
decrease rapidly; and (4) one or more factors (e.g., food availability, 
fecundity, disease, predation, genetics, environment) are strongly 
influencing the subspecies' population dynamics in one or more areas. 
High-amplitude, high-frequency fluctuations in small, isolated 
populations make the San Bernardino kangaroo rat extremely susceptible 
to local extirpation.
    Areas that contain low densities of San Bernardino kangaroo rats 
may be important for dispersal, genetic exchange, colonization of newly 
suitable habitat, and re-colonization of areas after severe storm 
events. The dynamic nature of the alluvial habitat leads to a situation 
where not all of the habitat associated with alluvial processes is 
suitable for the species at any point in time. However, areas generally 
considered unsuitable habitat, such as out-of-production vineyards and 
margins of orchards, can and do develop into suitable habitat for the 
subspecies through natural processes (67 FR 19812). The San Bernardino 
kangaroo rat has been documented in areas containing suitable soils 
that have been altered due to human disturbance not typically 
associated with the subspecies, including nonnative grasslands; margins 
of orchards and out-of-use vineyards from adjacent, mature stage 
alluvial sage scrub with greater than 50 percent canopy cover; and 
areas of wildland/urban interface within floodplains or terraces and 
adjacent to occupied habitat (67 FR 19812, April 23, 2002). These 
upland areas can support individuals for repopulation of wash areas 
extirpated by flood events (Pavelka 2006). This can occur directly by 
dispersal of adult individuals, or indirectly through dispersal of 
offspring (Pavelka 2006).
    Little is known about home range size, dispersal distances, or 
other spatial requirements of the San Bernardino kangaroo rat. However, 
home ranges for the Merriam's kangaroo rat in the Palm Springs, 
California, area averaged 0.8 ac (0.3 ha) for males and 0.8 ac (0.3 ha) 
for females (Behrends et al. 1986, p. 204). Furthermore, Blair (1943, 
p. 26) reported much larger home ranges for Merriam's kangaroo rats in 
New Mexico, where home ranges averaged 4.1 ac (1.7 ha) for males and 
3.9 ac (1.6 ha) for females. Space requirements for the San Bernardino 
kangaroo rat likely vary according to season, age and sex of animal, 
food availability, and other factors. Although outlying areas of their 
home ranges may overlap, Dipodomys adults actively defend small core 
areas near their burrows (Jones 1993, p. 583). Home range overlap 
between males and between males and females is extensive, but female-
female overlap is slight (Jones 1993, p. 584). The degree of 
competition between San Bernardino kangaroo rats and sympatric (living 
in the same geographical area) species of kangaroo rats for food and 
other resources is not presently known. While we do not have sufficient 
information to quantify the home range required by the San Bernardino 
kangaroo rat, through the delineation of critical habitat in wash and 
upland areas, it is likely that we have included sufficient areas to 
provide the space needed to maintain the home range for this subspecies 
in this proposed revised critical habitat designation.

Food

    As stated in the previous sections, the alluvial sage scrub plant 
community occupied by the San Bernardino kangaroo rat provides food 
resources for the subspecies. However, little is known about the 
specific diet of San Bernardino kangaroo rats. They emerge from their 
burrow systems at sunset and feed at night, when they are most active. 
San Bernardino kangaroo rats are generally granivorous (feed on seeds 
and grains) and like most Merriam's kangaroo rats, often store large 
quantities of seeds in surface pits for later consumption (Reichman and 
Price 1993, p. 540; Reynolds 1958, p. 126). This species feeds 
primarily on the seeds of alluvial sage scrub species, but green 
vegetation and insects can also be important seasonal food sources. 
Insects, when available, have been documented to constitute as much as 
50 percent of a kangaroo rat's diet (Reichman and Price 1993, p. 540).
    Wilson et al. (1985, p. 731) reported that in comparison to other 
rodents, Merriam's kangaroo rat, and heteromyids in general, have 
relatively low reproductive output that can be linked to food 
resources. Rainfall and

[[Page 33813]]

the availability of food have been cited as factors affecting kangaroo 
rat populations. Droughts lasting more than a year can cause rapid 
declines in population numbers after seed caches are depleted 
(Goldingay et al. 1997, p. 56).

Cover or Shelter

    San Bernardino kangaroo rats depend on proper soils for burrowing 
and vegetative cover for shelter from predation. Potential predators 
include the common barn owl (Tyto alba), great horned owl (Bubo 
virginianus), long-eared owl (Asio otus), gray fox (Urocyon 
cinereoargenteus), coyote (Canis latrans), long-tailed weasel (Mustela 
frenata), bobcat (Felis rufus), badger (Taxidea taxus), San Diego 
gopher snake (Pituophis melanoleucus annectens), California king snake 
(Lampropeltis getulus californiae), red diamond rattlesnake (Crotalus 
ruber), southern Pacific rattlesnake (Crotalus viridus), and domestic 
cats (Felis cattus) (Bolger et al. 1997, p. 560; 67 FR 19812, April 23, 
2002).

Primary Constituent Elements for the San Bernardino Kangaroo Rat

    Under the Act and its implementing regulations, we are required to 
identify the known physical and biological features (PCEs) within the 
geographical area occupied by the San Bernardino kangaroo rat at the 
time of listing, which may require special management considerations or 
protection.
    Based on our current knowledge of the life history, biology, and 
ecology of the San Bernardino kangaroo rat and the requirements of the 
habitat to sustain the essential life history functions of the 
subspecies, we have determined that the PCEs specific to the San 
Bernardino kangaroo are:
    (1) Alluvial fans, washes, and associated floodplain areas 
containing soils consisting predominately of sand, loamy sand, sandy 
loam, and loam, which provide burrowing habitat necessary for 
sheltering and rearing offspring, storing food in surface caches, and 
movement between occupied patches;
    (2) Upland areas adjacent to alluvial fans, washes, and associated 
floodplain areas containing alluvial sage scrub habitat and associated 
vegetation, such as coastal sage scrub and chamise chaparral, with up 
to approximately 50 percent canopy cover providing protection from 
predators, while leaving bare ground and open areas necessary for 
foraging and movement of this subspecies; and
    (3) Upland areas adjacent to alluvial fans, washes, and associated 
floodplain areas, which may include marginal habitat such as alluvial 
sage scrub with greater than 50 percent canopy cover with patches of 
suitable soils (PCE 1) that support individuals for re-population of 
wash areas following flood events. These areas may include agricultural 
lands, areas of inactive aggregate mining activities, and urban/
wildland interfaces.
    This proposed revision to the critical habitat designation is 
designed for the conservation of PCEs necessary to support the life 
history functions that were the basis for the proposal and the areas 
containing the PCEs. Because not all life history functions require all 
the PCEs, not all proposed revised critical habitat units will contain 
all the PCEs.

Special Management Considerations or Protection

    When designating critical habitat, we assess whether the areas 
determined to be occupied at the time of listing contain features 
essential to the conservation of the subspecies that may require 
special management considerations or protection. We have also 
considered how revising the current designation of critical habitat 
highlights habitat in need of special management considerations or 
protection.
    The majority of all remaining suitable habitat, and the long-term 
persistence of the San Bernardino kangaroo rat, is threatened by the 
direct and indirect effects of: sand and gravel mining; construction, 
operation, and maintenance of flood control structures; water 
conservation activities; urban and industrial development; agricultural 
activities; and off-road vehicle activity. With an expanding human 
population in the region, it is likely that these activities will 
continue to threaten the habitat and PCEs upon which the San Bernardino 
kangaroo rat depends.
    Sand and gravel mining operations have degraded San Bernardino 
kangaroo rat habitat in all of the proposed revised critical habitat 
units, with major operations occurring in the Santa Ana River and Lytle 
Creek washes. Mining activities directly affect the PCEs for the 
subspecies by altering soil composition and structure, and by stripping 
away vegetative cover (PCEs 1 and 2). Furthermore, flood control 
structures are often built to protect mining operations from flood 
damage. This alters the hydrology essential for maintaining proper soil 
and alluvial sage scrub habitat for the San Bernardino kangaroo rat 
(PCEs 1 and 2). Special management considerations or protection may be 
required to minimize effects of mining activities on alluvial sage 
scrub habitat and the natural hydrological processes that maintain 
proper alluvial sage scrub conditions for the San Bernardino kangaroo 
rat. Such management may include restoring habitat in areas degraded 
from past mining activities to conditions suitable for this subspecies.
    Flood control and water conservation activities related to 
increasing human population and development have had major impacts on 
San Bernardino kangaroo rat habitat and the alluvial processes that 
maintain habitat in each of the proposed revised critical habitat 
units. Flood control berms, levees, and concrete-lined channels 
increase severity (velocity and scour) of flood events in lower 
elevations within the flood plain, and cut off upland portions of 
alluvial sage scrub habitat from hydrological processes that maintain 
suitable San Bernardino kangaroo rat conditions (PCEs 1, 2, and 3). In 
the absence of periodic flooding and scouring, upland alluvial sage 
scrub habitat increases in cover and in density of nonnative vegetation 
to the point where the open canopy and ground conditions (PCE 2) 
preferred by the subspecies no longer exist (Service 2004, p. 293). 
Some flood control structures, such as concrete channels, can prevent 
movement and dispersal between occupied areas of the alluvial wash and 
floodplain. Decades of groundwater pumping have severely depleted 
groundwater reserves within San Bernardino kangaroo rat habitat and 
have resulted in an ever-increasing need to recharge groundwater 
supplies by percolation of local or imported water sources into the 
local groundwater basin (Service 2004, p. 293). Further habitat 
degradation occurs where groundwater recharge ponds (percolation 
basins) have been constructed. Recharge structures are unsuitable for 
the San Bernardino kangaroo rat due to periodic standing water. These 
structures are especially evident in the Santa Ana River and San 
Jacinto River washes. Special management considerations or protection 
may be required to minimize effects of flood control and water 
conservation activities on alluvial sage scrub habitat and the natural 
hydrological processes that maintain proper alluvial sage scrub 
conditions for the San Bernardino kangaroo rat.
    Development projects pose a serious threat to San Bernardino 
kangaroo rat habitat in all three proposed revised critical habitat 
units. As the human population of the surrounding area continues to 
increase, the threat of development encroaching upon alluvial washes 
and associated upland areas will persist (PCEs 1, 2, and 3). Large-
scale

[[Page 33814]]

development projects, like the Lytle Creek North Master Planned 
Community (described below), permanently eliminate and fragment habitat 
containing the PCEs for the subspecies. Furthermore, continued 
fragmentation of habitat is likely to promote higher levels of 
predation by native animals (Bolger et al. 1997, p. 560) and urban-
associated animals (e.g., domestic cats, opossums (Didelphis 
virginianus), and striped skunks (Mephitis mephitis)) as the interface 
between natural habitat and urban areas is increased (Churcher and 
Lawton 1987, p. 452). Roadways and bridges built to accommodate the 
growing population in the area constrict channel width and contribute 
to the removal of alluvial fan habitat from normal hydrological 
processes (PCE 1). The downstream alluvial benches become isolated 
behind the fill used to construct the bridge within the channel area 
and do not experience natural flood-borne scour and deposition. Pier 
and footing placement within channels is a typical necessary bridge 
design feature. Instream piers create scour areas in front of the 
piers, increase water velocity through the embankments and piers (which 
can result in downstream erosion), and create a permanent shadow over 
habitat under the bridge. These factors typically result in permanently 
degraded habitat for San Bernardino kangaroo rat even though high flows 
are seasonal in this area. Special management considerations or 
protection may be required to minimize the impacts of development 
within the alluvial wash and adjacent upland areas. Areas of the 
alluvial washes and floodplains adjacent to development may require 
exclusionary fencing and signage to minimize human and domestic animal 
disturbance of San Bernardino kangaroo rat habitat. Because this 
subspecies is active at night, lights from adjacent developed areas 
should be minimized and directed away from San Bernardino kangaroo rat 
habitat.
    Agricultural activities adjacent to all three proposed revised 
critical habitat units occasionally result in the discing of patches of 
suitable or occupied habitat that may be distributed throughout upland 
agricultural areas. Discing destroys San Bernardino kangaroo rat 
burrows and degrades remaining vegetation associations (Service 2004, 
p. 293) (PCEs 1 and 2). This can contribute to the susceptibility of 
local populations to extinction during large-scale flood events by 
restricting San Bernardino kangaroo rats to areas most vulnerable to 
flooding (i.e., lower elevations of the floodplain) (Service 2004, p. 
293). Special management considerations or protection may be required 
to minimize effects of agricultural activities on alluvial sage scrub 
habitat.
    Unauthorized off-road vehicle activity continues to be a threat to 
San Bernardino kangaroo rat habitat in the San Jacinto River wash area. 
Most of this activity occurs within the wash downstream of the East 
Main Street/Lake Park Drive Bridge. Off-road activity that goes 
unchecked directly damages plant communities, the soil crust, and the 
burrow systems of kangaroo rats, thereby degrading habitat (Bury et al. 
1977, p. 16; Service 2004, p. 293) (PCEs 1 and 2). Special management 
considerations or protection, such as exclusionary fencing, additional 
enforcement, and signage placed around areas of the wash, may be needed 
to minimize impacts from unauthorized off-road vehicle use.

Criteria Used To Identify Critical Habitat

    We are proposing to revise critical habitat for the San Bernardino 
kangaroo rat in areas that we have determined were occupied at the time 
of listing, and that contain sufficient primary constituent elements 
(PCEs) to support life history functions essential for the conservation 
of the species. Lands are proposed for revised designation based on 
sufficient PCEs being present to support the life processes of the 
species. Some lands contain all PCEs and support multiple life 
processes. Some lands contain only a portion of the PCEs necessary to 
support the particular use of that habitat.
    We define occupied habitat as: (a) Those areas containing 
occurrence data from the time of listing (1980 to 1998); (b) those 
areas containing occurrence data since the time of listing (1998 to 
present); (c) areas adjacent to and between occurrence points that 
maintain connectivity of occurrences in one continuous patch of 
suitable habitat. As discussed in the Background section of this 
proposed rule, occurrences discovered since the listing of the 
subspecies in 1998 are within areas known to be occupied at the time of 
listing (Santa Ana River wash, Lytle and Cajon washes, and San Jacinto 
River area).
    In this proposed revised designation we have focused primarily on 
core populations (i.e., areas where the subspecies has been repeatedly 
detected through live trapping) that are considered necessary for 
conservation and recovery of the San Bernardino kangaroo rat. We 
believe protecting these core populations is what is necessary for 
recovery of the species. Protecting peripheral populations, or areas of 
degraded habitat where sitings are sporadic is not necessary for 
recovery.
    Utilizing 2005 aerial imagery and occurrence data used to determine 
areas of occupancy, we delineated proposed revised critical habitat on 
maps to include non-degraded alluvial fans, washes, floodplains, and 
adjacent upland areas containing the PCEs required by the San 
Bernardino kangaroo rat. We then made site visits accompanied by 
subspecies experts to confirm the presence of PCEs in the areas 
delineated on the maps. Areas determined not to contain any of the PCEs 
(i.e., degraded) during site visits are not included in the areas 
proposed as revised critical habitat. Because of the importance of 
upland habitat for source populations to re-populate wash areas 
following flood events, we include non-degraded (containing one or more 
PCEs) upland habitat adjacent to occupied wash habitat containing 
appropriate soils and vegetation community in this proposed revised 
designation.
    When determining the proposed revisions to critical habitat 
boundaries, we made every effort to avoid including developed areas 
such as buildings, paved areas, and other structures that lack PCEs for 
the San Bernardino kangaroo rat. Areas currently being used for sand/
gravel mining operations (e.g., pits, staging areas) do not contain the 
PCEs required by the San Bernardino kangaroo rat. The scale of the maps 
prepared under the parameters for publication within the Code of 
Federal Regulations may not reflect the exclusion of such developed 
areas. Any developed structures and the land under them inadvertently 
left inside critical habitat boundaries shown on the maps of this 
proposed revision to critical habitat have been excluded by text in 
this rule and are not proposed for designation as critical habitat. 
Therefore, Federal actions limited to these areas would not trigger 
section 7 consultation, unless they may affect the subspecies or PCEs 
in adjacent critical habitat.

Summary of Proposed Changes to Currently Designated Critical Habitat

    The areas identified in this proposed rule constitute a proposed 
revision of the critical habitat designation for the San Bernardino 
kangaroo rat, published on April 23, 2002 (67 FR 19812). For maps 
showing existing and proposed revised critical habitat visit our Web 
site at https://carlsbad.fws.gov.

[[Page 33815]]

    Our proposed revised critical habitat designation is substantially 
smaller than the existing designation. Given the new information that 
has become available to us in the five years since the previous 
designation, we find that we erroneously designated some areas. We find 
that areas previously proposed but not proposed in this rule are not 
essential to the conservation of the species, because of new 
information (see Criteria Used To Identify Critical Habitat section). 
The changes in this rule are due to several factors. Better biological 
information has allowed us to more specifically define PCEs for this 
species, and site visits in December 2006 and January 2007 allowed us 
to more precisely define these areas on the ground. This allowed us to 
remove areas that do not meet our criteria for features that are 
essential to the conservation of the species. The 2002 critical habitat 
designation included areas that supported few occurrence records. Such 
areas of low density occupation, or sporadic occupancy, have been 
removed from the proposed revised designation, for such areas do not 
represent core populations and, therefore, are not necessary for the 
conservation and recovery of the species. Finally, we have employed 
refined mapping techniques in the current revision, which have allowed 
us to more precisely map areas that contain PCEs. This more refined 
approach has allowed us to remove areas that do not meet the definition 
of critical habitat.
    The main differences in this proposed revised designation include 
the following:
    (1) On the basis of our new analyses, we have determined that 
portions of existing Unit 1 (Santa Ana River), Unit 2 (Lytle and Cajon 
Creeks), and Unit 3 (San Jacinto River), and all of Unit 4 (Etiwanda 
Alluvial Fan and Wash) do not contain PCEs in the quality and quantity 
needed for conservation of the species or do not support core 
populations of the taxon. These areas total 24,211 ac (9,798 ha) of 
habitat originally designated as critical habitat in 2002. Therefore we 
are not proposing to include these areas in our proposed revision to 
critical habitat. The following paragraphs provide unit by unit 
explanations for why areas previously designated as critical habitat no 
longer fit our definition of critical habitat for the San Bernardino 
kangaroo rat.
    We have removed approximately 5,311 ac (2,149 ha) within Unit 1 
from our proposed revision to critical habitat, largely because 
portions of the Unit do not contain the PCEs, but also because 
occurrence data for some areas indicates that they do not support a 
core population of San Bernardino kangaroo rat. South of Mill Creek, a 
flood control levee has cut off habitat from fluvial processes, which 
has resulted in overgrown vegetation and water retention basins that 
are unsuitable habitat conditions for the subspecies. A large area 
extending from the existing critical habitat in and south of Plunge 
Creek west to the confluence of City Creek with the Santa Ana River has 
been degraded through mining operations, flood control structures (and 
the subsequent loss of fluvial influence), and water retention basins. 
The habitat downstream of the Tippecanoe Avenue Bridge is heavily 
channelized with steep banks inhibiting the use of upland habitat; we 
do not have data indicating that this area is occupied. Because these 
areas do not contain PCEs and/or do not support core populations, we 
are not including them in the proposed revision to critical habitat.
    We have removed approximately 9,284 ac (3,757 ha) within Unit 2 
from our proposed revision to critical habitat, largely because 
portions of the Unit do not contain the PCEs, but also because 
occurrence data for some areas indicates that they do not support a 
core population of San Bernardino kangaroo rat. Two areas northeast of 
the main Lytle-Cajon Creek unit contain habitat that has been degraded 
and these areas are largely unoccupied. The southernmost portion of 
Lytle Creek contains habitat that has been degraded through surface 
mining and flood control structures, making this area unsuitable for 
the subspecies. The upper reaches of both Lytle and Cajon Creeks 
contain large rocky substrates that do not provide habitat for this 
subspecies and we have no recent occurrence data for these upstream 
areas. Portions of habitat along the Lytle Creek arm have been degraded 
from sand and gravel mining operations and associated infrastructure. 
Approximately 670 ac (271 ha) of existing critical habitat north of 
Lytle Creek and east of I-15 is currently under development for the 
Lytle Creek North development project, and was addressed through formal 
section 7 consultation with the Service. A large expanse of a remnant 
flood plain south of Lytle Creek and I-15, and west of Riverside Avenue 
is partially developed and does not contain the PCEs for the 
subspecies. This area is void of fluvial influence and is cut off from 
the core population by roadways. Because these areas do not contain 
PCEs and/or do not support core populations, we are not including them 
in the proposed revision to critical habitat.
    We have removed approximately 4,796 ac (1,941 ha) within Unit 3 
from our proposed revision to critical habitat, largely because 
portions of the Unit do not contain the PCEs, but also because 
occurrence data for some areas indicates that they do not support a 
core population of San Bernardino kangaroo rat. Bautista Creek and the 
downstream reach of the San Jacinto River are largely channelized, and 
do not provide suitable habitat or contain the PCEs essential to the 
San Bernardino kangaroo rat. These channelized areas prevent 
connectivity with the core population in the San Jacinto wash. We have 
do not have occurrence data or habitat condition data for the two 
tributaries on Tribal land north of the San Jacinto wash and are not 
proposing critical habitat on Tribal lands (see Government-to-
Government Relationship with Tribes section). Portions of the habitat 
downstream of the Bautista Creek confluence have been or are in the 
process of being developed or are being used for water conservation 
activities and therefore this habitat does not contain the PCEs. 
Because these areas do not contain PCEs and/or do not support core 
populations, we are not including them in the proposed revision to 
critical habitat.
    We have removed approximately 4,820 ac (1,951 ha) within Unit 4 
from our proposed revision to critical habitat because Unit 4 consists 
largely of unoccupied areas that are not essential to the conservation 
of the San Bernardino kangaroo rat. Occupied areas within this unit do 
not contain the PCEs necessary for the subspecies.
    (2) We re-evaluated and revised the PCEs as needed in light of 
Homebuilder's Ass'n of Northern Cal. v. U.S. Fish and Wildlife Service, 
268 F. Supp.2d 1197 (E.D. Cal. 2003), other applicable law, and current 
Service guidelines and policies. We propose to revise the PCEs to 
provide more specificity with regards to the location of and necessity 
for suitable soil types, vegetative habitat, and upland areas related 
to the biological needs of the subspecies. We also include a range of 
the preferred percentage of vegetative cover. Revisions to the PCEs 
alone did not result in the removal of existing critical habitat from 
this proposed revised critical habitat designation.

Proposed Revisions to the Critical Habitat Designation

    We are proposing approximately 9,079 ac (3,674 ha) within three 
units as critical habitat for the San Bernardino kangaroo rat. These 
units, which generally correspond to the units in the 2002 designation, 
if finalized, would

[[Page 33816]]

entirely replace the current critical habitat designation for the San 
Bernardino kangaroo rat in 50 CFR 17.95(a). The critical habitat areas 
described below constitute our best assessment currently of areas 
occupied at the time of listing containing the PCEs that may require 
special management considerations or protection. The three units 
proposed as critical habitat are: (1) Unit 1--Santa Ana River Wash, (2) 
Unit 2--Lytle/Cajon Creek Wash, and (3) Unit 3--San Jacinto River Wash.
    Of the 9,079 ac (3,674 ha) being proposed as revised critical 
habitat, we are proposing to exclude approximately 2,544 ac (1,029 ha) 
from the final critical habitat designation under section 4(b)(2) of 
the Act. See Exclusions Under Section 4(b)(2) of the Act section for a 
detailed discussion.
    The approximate area (ac, ha) encompassed within each proposed 
revised critical habitat unit, land ownership, and areas proposed for 
exclusion from the final critical habitat designation are shown in 
Table 1.

 Table 1.--Area (Acres (ac), Hectares (ha)) Being Proposed as Revised Critical Habitat, Land Ownership, and Area
 Being Proposed for Exclusion From the Final Critical Habitat Designation for the San Bernardino Kangaroo Rat in
                                San Bernardino and Riverside Counties, California
               [Area estimates reflect all land within proposed critical habitat unit boundaries]
----------------------------------------------------------------------------------------------------------------
                                                                    Area proposed as      Area being considered
        Critical habitat unit               Land ownership          revised critical        for exclusion from
                                                                        habitat           final critical habitat
----------------------------------------------------------------------------------------------------------------
1. Santa Ana River Wash, San           Federal (BLM) \1\......  559 ac (226 ha)........  00 ac (00 ha).
 Bernardino County.
                                       Local\2\...............  268 ac (109 ha)........  268 ac (109 ha).
                                       Private................  2,797 ac (1,132 ha)....  742 ac (300 ha).
                                                               -------------------------------------------------
                                       Subtotal...............  3,624 ac (1,467 ha)....
----------------------------------------------------------------------------------------------------------------
2. Lytle/Cajon Creek Wash, San         Federal (USFS) \3\.....  89 ac (36 ha)..........  00 ac (00 ha).
 Bernardino County.
                                       Private................  4,597 ac (1,860 ha)....  1,271 ac (514 ha).
                                                               -------------------------------------------------
                                       Subtotal...............  4,686 ac (1,896 ha)....
----------------------------------------------------------------------------------------------------------------
3. San Jacinto River Wash, Riverside   Water District \4\.....  506 ac (205 ha)........  00 ac (00 ha).
 County.
                                       Local Flood\5\.........  94 ac (38 ha)..........  94 ac (38 ha).
                                       Private................  169 ac (68 ha).........  169 ac (68 ha).
                                                               -------------------------------------------------
                                       Subtotal...............  769 ac (311 ha)........