Endangered and Threatened Wildlife and Plants; 90-Day Finding on Petition To Delist the Stephens' Kangaroo Rat and Initiation of a 5-Year Review

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Notice of 90-day petition finding and initiation of status review for the 12-month finding and 5-year review.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), announce a 90-day finding for a petition to remove the Stephens' kangaroo rat (Dipodomys stephensi) from the Federal List of Threatened and Endangered Wildlife and Plants pursuant to the Endangered Species Act (Act) (16 U.S.C. 1531 et seq.). We find that the petition presents substantial information and are initiating a status review to determine if delisting this species is warranted. We are requesting submission of any new information (best scientific and commercial data) on the Stephens' kangaroo rat since its original listing as an endangered species in 1988. Following this status review, we will issue a 12-month finding on the petition to delist. Because a status review is also required for the 5-year review of listed species under section 4(c)(2)(A) of the Act, we are electing to prepare these reviews simultaneously. At the conclusion of these simultaneous reviews, we will issue the 12-month finding on the petition, as provided in section 4(b)(3)(B) of the Act, and make the requisite finding under section 4(c)(2)(B) of the Act based on the results of the 5-year review.

DATES:

The 90-day finding announced in this document was made on March 24, 2004. To be considered in the 12-month finding on this petition, comments and information should be submitted to us by June 21, 2004.

ADDRESSES:

Comments, material, information, or questions concerning this petition and finding should be sent to the Field Supervisor, Carlsbad Fish and Wildlife Office, U.S. Fish and Wildlife Service, 6010 Hidden Valley Road, Carlsbad, California 92009. The petition and supporting information are available for public inspection by appointment during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT:

Jim Bartel, Field Supervisor, Carlsbad Fish and Wildlife Office, at the above address (telephone: 760/431-9440; fax: 760/431-9618).

SUPPLEMENTARY INFORMATION:

Background

Section 4(b)(3)(A) of the Act requires that we make a finding on whether a petition to list, delist, or reclassify a species presents substantial scientific or commercial information indicating that the petitioned action may be warranted. To the maximum extent practicable, this finding is to be made within 90 days of receipt of the petition, and the finding is to be published promptly in the Federal Register. If we find substantial information is present, we are required to promptly commence a review of the status of the species (50 CFR 424.14). “Substantial information” is defined in 50 CFR 424.14(b) as “that amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted.” Petitioners need not prove that the petitioned action is warranted to support a “substantial” finding; instead, the key consideration in evaluating a petition for substantiality involves demonstration of the reliability and adequacy of the information supporting the action advocated by the petition.

When considering an action for listing, delisting, or reclassifying a species, we are required to determine whether a species is endangered or threatened based on one or more of the five listing factors as described at 50 CFR 424.11. These factors are given as: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; and (E) other natural or manmade factors affecting the continued existence of the species. Delisting a species must be supported by the best scientific and commercial data available and only considered if such data substantiates that the species is neither endangered nor threatened for one or more of the following reasons: (1) The species is considered extinct; (2) the species is considered to be recovered; and/or (3) the original data available when the species was listed, or the interpretation of such data, were in error.

We received two similar petitions from Mr. Robert Eli Perkins requesting us to delist the Stephens' kangaroo rat from the Federal List of Threatened and Endangered Wildlife and Plants pursuant to the Act. The first petition, submitted on behalf of the Riverside County Farm Bureau (RCFB), was received on May 1, 1995. We subsequently sent a letter on June 12, 1995, to the RCFB acknowledging the receipt of the petition. On August 13, 1997, the RCFB sent us an inquiry regarding the status of the delisting petition and requesting clarification as to whether we had the funds or staff to respond with a 90-day finding to the petition. We sent another letter to the RCFB on August 26, 1997, stating that we were unable to review the petition and publish our 90-day finding due to limited resources. We also provided the RCFB with additional information concerning our Listing Priority Guidance for Fiscal Year 1997, which indicated that delisting petitions ranked as a low-priority Tier 3 action and that higher priority work took precedence. We received a resubmittal of the first petition to delist the Stephens' kangaroo rat from Mr. Perkins on February 25, 2002, and sent a letter acknowledging the receipt of the second petition to Mr. Perkins on August 6, 2002. The second petition repeated the same information as the first petition, and also stated that delisting is warranted as a result of the Riverside County Habitat Conservation Agency's conservation measures.

The petition provides information on the species' range, habitat requirements, population size, population density, reproductive ability, ability to persist in small patches, and colonization capability, and states that this information demonstrates that the species was listed in error. The petition also states that delisting is warranted because the existing habitat conservation measures identified in a Habitat Conservation Plan (HCP) by the Riverside County Habitat Conservation Agency (RCHCA) are adequate.

Biology and Distribution

The Stephens' kangaroo rat is a medium-sized, five-toed, broad-faced kangaroo rat of the rodent family Heteromyidae. Kangaroo rats (genus Dipodomys) are nocturnal, burrow-dwelling rodents found in semiarid and arid habitats of western North America (Eisenberg 1963). Members of this genus are characterized by their external fur-lined cheek pouches used for transporting seeds to safe caches; large hind legs adapted for rapid hopping; relatively small front legs; long tails; and large heads (Brown et al. 1979).

The Stephens' kangaroo rat reaches its highest densities in intermediate successional stage grassland communities characterized by moderate to high amounts of bare ground, high forb cover, moderate slopes, and well-drained soils (O'Farrell and Uptain 1987, Anderson and O'Farrell, in review). This species prefers grassland communities dominated by herbaceous plants rather than by annual grasses because annual herbs rapidly break down after drying, which results in substantial patches of bare ground (O'Farrell and Clark 1987), which provide suitable conditions for the species' specialized mode of locomotion (Bartholomew and Caswell 1951). Because of these habitat preferences, natural or artificial disturbances that prevent the development of dense ground cover, and/or succession of grassland communities to later stage shrub communities can be beneficial to the species (O'Farrell 1993; Price et al. 1994). However, too much disturbance may also be detrimental to the species (SJM Biological Consultants 1999). While disturbances such as off-road vehicle use, farming, and grazing may be beneficial to the species by maintaining bare areas, such disturbances, if too excessive or intense, may be harmful, resulting in burrow destruction and possible changes to the vegetation community. Further research is needed to determine at what levels and intensities these disturbances become detrimental to the species.

The Stephens' kangaroo rat's known historic range is small for rodents in general, and in particular for kangaroo rats (Price and Endo 1989). Its historic range encompassed extreme southwestern San Bernardino, western Riverside, and parts of northern and central San Diego Counties in southern California (Grinnell 1922; Lackey 1967; Bleich 1973; O'Farrell et al. 1986; O'Farrell and Uptain 1989; Pacific Southwest Biological Services, Inc. 1993; Ogden Environmental and Energy Services Co., Inc. 1997). However, massive expansion of urban, agricultural, and recreational development throughout the species' historic range during the past century resulted in severe losses of habitat and fragmentation of remaining populations (O'Farrell and Clark 1987; Price and Endo 1989).

On September 30, 1988, we listed the Stephens' kangaroo rat (Dipodomys stephensi) as endangered (53 FR 38465) pursuant to the Act. This determination was based upon the best scientific and commercial information available at the time of listing. As stated in the final rule, this action was taken, in part, because of significant known and impending losses of habitat due to development. We did not designate critical habitat for the Stephens' kangaroo rat at the time of listing because such action was not considered prudent at that time. We published a notice of availability for the Draft Recovery Plan for the Stephens' kangaroo rat in the Federal Register on June 23, 1997 (62 FR 33799) and are currently working to finalize the Recovery Plan based on public comment and information that has become available since the draft publication.

Review of Petition

We have reviewed the petition and its supporting documents, as well as information in our files. We have found that substantial information relating to the distribution of the species and factors threatening its continued existence has become available since the Stephens' kangaroo rat was listed as an endangered species. We believe that it is appropriate to consider this information, and any other new information available about this species and the threats it may face, in a status review.

The petition states that the size of the known range for the Stephens' kangaroo rat has increased considerably since we listed the species. Federal listing of the Stephens' kangaroo rat prompted several focused surveys for the species in response to proposed development projects. These surveys occurred throughout, and adjacent to, the species' known range. As discussed in the Draft Recovery Plan for the Stephens' Kangaroo Rat (62 FR 33799), the range of the species is now known to be larger, with new populations in the general vicinities of Norco and Anza in Riverside County, and Guejito Ranch and Ramona in San Diego County (USFWS 1997). Significant questions remain about the amount and quality of occupied habitat within the current range, and the species' ability to persist in the face of expanding agricultural and urban development; however, we consider the expansion of the known range to be an issue relevant to the listing status of the Stephens' kangaroo rat that warrants further investigation.

The petition also states that we may have overestimated the impact of actions such as grazing, off-road vehicle use, and farming in the listing rule. The listing rule identified these types of actions as potentially reducing habitat suitability. When properly managed, certain types of activities, such as grazing, off-road vehicle use, and farming, can cause artificial disturbance and promote bare ground, which may benefit the species. As discussed earlier, the best suitable habitat for the Stephens' kangaroo rat consists of early to intermediate successional stage grassland communities characterized by moderate to high amounts of bare ground, high forb cover, moderate slopes, and well-drained soils. Without a disturbance event, succession to dense ground cover (i.e., shrubs and invasive annual grasses) will render the habitat unsuitable in a relatively short time (O'Farrell and Uptain 1989). Maintenance of suitable Stephens' kangaroo rat habitat may require perpetual habitat manipulation to maintain the sparse vegetation conditions preferred by this species. In our status review, we will further evaluate actions such as grazing, off-road vehicle use, and farming, and assess their impact to the Stephens' kangaroo rat.

The petition also questioned the need for listing the species when most of the lands in the core reserves under the HCP for the Stephens' kangaroo rat in western Riverside County were already under public ownership at the time of listing. The petitioner states that listing was not necessary because the missions of these public lands were compatible with the preservation of the species. Prior to listing, conservation measures for the species were not developed specifically for the preservation of the species in perpetuity. Since Federal listing, several public land agencies have participated in conservation measures or developed conservation strategies for ensuring the species' long-term survival. In our status review, we will examine the efficacy of these conservation measures by the various public land agencies.

The petition also stated that the species warranted delisting because the RCHCA provided adequate habitat conservation measures for the species through the HCP for the Stephens' kangaroo rat in western Riverside County, which was initiated following our listing of the species in 1988. Following the completion of the HCP in March 1996 (RCHCA 1996), we issued a 30-year Incidental Take Permit pursuant to section 10(a)(1)(B) of the Act to the RCHCA and other jurisdictional entities on May 2, 1996. Under the HCP, the RCHCA and other permittees agreed to offset “take” of the Stephens” kangaroo rat by funding and establishing a permanent reserve system consisting of seven core reserves for the conservation, preservation, and enhancement of the Stephens' kangaroo rat and its habitat within western Riverside County. We are also currently working with Riverside County and local jurisdictions on the development of a Western Riverside Multiple Species Habitat Conservation Plan (MSHCP). If approved, the MSHCP will provide for the conservation, management, and “take” authorization of the Stephens' kangaroo rat outside the boundaries of the existing HCP for the Stephens' kangaroo rat in western Riverside County. We are also working with San Diego County toward the development of a Multiple Species Conservation Program North County Subarea Plan that, if approved, will also provide for the conservation, management, and take authorization of the Stephens' kangaroo rat in northern San Diego County. The Multiple Habitat Conservation Program of northwestern San Diego County might also contribute toward the conservation and management of this species. Both public and private landowners have undertaken significant measures to conserve the Stephens' kangaroo rat. These conservation efforts are also an issue relevant to the listing status of the Stephens' kangaroo rat that warrants further evaluation in a status review.

Finding

We have reviewed the petition and the supporting documents, as well as other information in our files. We find that the petition and other information in our files presents substantial information that delisting the Stephens' kangaroo rat may be warranted, and are initiating a status review. We will issue a 12-month finding in accordance with section 4(b)(3)(B) of the Act as to whether or not delisting is warranted.

Five-Year Review

Section 4(c)(2)(A) of the Act requires that we conduct a review of listed species at least once every five years. We are then, under section 4(c)(2)(B) and the provisions of subsection (a) and (b), to determine, on the basis of such a review, whether or not any species should be removed from the List (delisted), or reclassified from endangered to threatened, or threatened to endangered. Our regulations at 50 CFR 424.21 require that we publish a notice in the Federal Register announcing those species currently under active review. This notice announces our active review of the Stephens' kangaroo rat.

Public Information Solicited

We are requesting information for both the 12-month finding and the 5-year review, as we are conducting these reviews simultaneously.

When we make a 90-day finding on a petition that substantial information exists to indicate that listing or delisting a species may be warranted, we are required to promptly commence a review of the status of the species. To ensure that the status review is complete and based on the best available scientific and commercial information, we are soliciting information on the Stephens' kangaroo rat. This includes information regarding historical and current distribution, biology and ecology, ongoing conservation measures for the species and its habitat, and threats (including wildfires) to the species and its habitat. We also request information regarding the adequacy of existing regulatory mechanisms. We request any additional information, comments, and suggestions from the public, other concerned governmental agencies, Tribes, the scientific community, industry or environmental entities, or any other interested parties concerning the status of the Stephens' kangaroo rat.

The 5-year review considers all new information available at the time of the review. This review will consider the best scientific and commercial data that have become available since the current listing determination or most recent status review, such as:

A. Species biology, including, but not limited to, population trends, distribution, abundance, demographics, and genetics;

B. Habitat conditions, including, but not limited to, amount, distribution, and suitability;

C. Conservation measures that have been implemented that benefit the species;

D. Threat status and trends;

E. Other new information, data, or corrections, including, but not limited to, taxonomic or nomenclatural changes, identification of erroneous information contained in the List, and improved analytical methods.

If you wish to comment for either the 12-month finding or the 5-year review, you may submit your comments and materials concerning this finding to the Field Supervisor, Carlsbad Fish and Wildlife Office (see ADDRESSES section). Our practice is to make comments, including names and home addresses of respondents, available for public review during regular business hours. Respondents may request that we withhold a respondent's identity, as allowable by law. If you wish us to withhold your name or address, you must state this request prominently at the beginning of your comment. However, we will not consider anonymous comments. To the extent consistent with applicable law, 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 Carlsbad address.

References Cited

A complete list of all references cited in this finding is available, upon request, from the Carlsbad Fish and Wildlife Office (see ADDRESSES section).

Authority

The authority for this action is section 4 of the Endangered Species Act of 1973 (16 U.S.C. 1531 et seq.).