E7-17679. Draft Recovery Plan for Columbia Basin Distinct Population Segment of the Pygmy Rabbit (Brachylagus idahoensis

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Notice of document availability for review and comment.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), announce the availability of a draft recovery plan for the Columbia Basin distinct population segment of the pygmy rabbit for public review and comment.

DATES:

We must receive any comments on the draft recovery plan on or before November 6, 2007.

ADDRESSES:

The draft recovery plan and reference materials are available for inspection, by appointment, during normal business hours at the following location: U.S. Fish and Wildlife Service, Upper Columbia Fish and Wildlife Office, 11103 East Montgomery Drive, Spokane, Washington 99206 (Telephone: [phone]). Submitted comments regarding the draft recovery plan will also be available for public inspection, by appointment, during normal business hours following the public review and comment period. Requests for copies of the draft recovery plan and submission of written comments or materials regarding the plan should be addressed to the Field Supervisor at the above address. An electronic copy of the draft recovery plan is also available at: http://endangered.fws.gov/​recovery/​index.html#plans.

FOR FURTHER INFORMATION CONTACT:

Chris Warren, Fish and Wildlife Biologist, by writing to the above address, by calling 509-893-8020, or by electronic mail at: [e-mail].

SUPPLEMENTARY INFORMATION:

Background

Recovery of endangered or threatened animals and plants is a primary goal of the Endangered Species Act (Act) (16 U.S.C. 1531 et seq.) and our endangered species program. Recovery means improvement of the status of listed species to the point at which listing is no longer required under the criteria set out in section 4(a)(1) of the Act. Recovery plans describe actions considered necessary for the conservation of the species, establish criteria for downlisting or delisting listed species, and estimate time and cost for implementing the measures needed for recovery.

Section 4(f) of the Act directs the Secretaries of Interior and Commerce to develop and implement recovery plans for species listed as endangered or threatened, unless such plans will not promote the conservation of the species. We and the National Marine Fisheries Service, as appropriate, have been delegated responsibility for administering the Act. Section 4(f) of the Act requires that public notice, and an opportunity for public review and comment, be provided during development of recovery plans. We will consider all information presented during the public comment period on each new or revised recovery plan. Substantive comments may or may not result in changes to a recovery plan. However, any substantive comments regarding recovery plan implementation will be forwarded to appropriate Federal agencies or other interested entities so that they can take these comments into account during the implementation of their respective management programs. Individual responses to submitted comments will not be provided.

The pygmy rabbit is the smallest rabbit species in North America, with adult lengths of under 1 foot and weights of less than 1 pound. The pygmy rabbit is distinguishable from other rabbit species by its small size, short ears, small hind legs, and lack of white on the tail. Historically, pygmy rabbits were found throughout the semi-arid sagebrush steppe biome of the Great Basin and adjacent intermountain regions of the western United States, including portions of Oregon, California, Nevada, Utah, Idaho, Montana, Wyoming, and Washington. Within this broad biome, pygmy rabbits are typically found in habitat types that include tall, dense stands of sagebrush (Artemesia spp.), on which they are highly dependent for both food and shelter throughout the year. The pygmy rabbit is one of only two rabbit species in North America that digs its own burrows and, therefore, is most often found in areas that also include relatively deep, loose soils that allow burrowing.

The pygmy rabbit has been present within the Columbia Basin, a geographic area that extends from northern Oregon through central Washington, for over 100,000 years. This distinct population segment of the pygmy rabbit, which is referred to as the Columbia Basin pygmy rabbit and is the subject of this draft recovery plan, is believed to have been disjunct from the remainder of the species' range for at least 10,000 years, as suggested by the fossil record, and possibly as long as 40,000 to 115,000 years, as suggested by population genetic analyses. Museum specimens and sighting records indicate that during the first half of the 20th century, the Columbia Basin pygmy rabbit likely occurred in portions of six Washington counties, including Douglas, Grant, Lincoln, Adams, Franklin, and Benton.

Columbia Basin pygmy rabbits were thought to be extirpated from Washington during the mid-1900s, however, they were again located in the State in 1979. Intensive surveys in 1987 and 1988 discovered five small subpopulations in southern Douglas County; three occurred on State lands and two on private lands. The number of Columbia Basin pygmy rabbit subpopulations and active burrows in Washington has declined dramatically over the past decade. In addition, surveys of the last known subpopulation conducted from 2004 through 2006 did not detect any animals, indicating that the Columbia Basin pygmy rabbit may have been extirpated from the wild. We listed this distinct population segment under emergency provisions of the Act in 2001, and fully listed it as endangered in 2003, without critical habitat.

Large-scale loss and fragmentation of native shrub-steppe habitats, primarily for agricultural development, likely played a primary role in the long-term decline of the Columbia Basin pygmy rabbit. Imminent threats related to small population size include chance environmental events (e.g., extreme weather), catastrophic habitat loss or resource failure (e.g., from wildfire), predation, disease, demographic limitations, loss of genetic diversity, and inbreeding.

In 2001, the Washington Department of Fish and Wildlife began a captive breeding program for the Columbia Basin pygmy rabbit. Ultimately, the goal of the captive breeding program is to facilitate future releases of captive-bred animals at suitable sites within the population's historical distribution to begin the process of its recovery in the wild. However, the captive purebred Columbia Basin pygmy rabbits did not produce enough offspring to accommodate reintroduction efforts, and only a minimal number of purebred animals have been available since the program's first breeding season in 2002. In addition, the available information indicates that the Columbia Basin pygmy rabbit has experienced a loss of genetic diversity as a result of inbreeding and genetic drift. Due to poor demographic, behavioral, physiological, and genetic indicators for pure Columbia Basin pygmy rabbit breeding efforts, intercross matings between Columbia Basin pygmy rabbits and pygmy rabbits of the same taxonomic classification from a discrete population in Idaho were initiated during the 2003 breeding season.

In March, 2007, 20 captive-bred pygmy rabbits were reintroduced to habitats historically occupied by the species within the Columbia Basin of central Washington. These captive-bred animals experienced a high level of predation over the first several weeks following their release. As of May 15, 2007, five of these animals remained alive and they will continue to be monitored throughout the 2007 breeding season. Just prior to the initial release effort, there were 86 individuals included in the captive breeding program, 3 of which were purebred Columbia Basin animals. At least one wild-born, and likely captive bred kit (approximately 1-month old) has been documented at the release site. The remaining captive-bred female was also observed displaying nesting behavior. The balance of the captive population and those recently released to the wild consist of intercross pygmy rabbits. Intercross breeding has helped facilitate genetic restoration of the Columbia Basin pygmy rabbit and is considered essential for recovery efforts. Currently, proposed measures to recover the Columbia Basin pygmy rabbit in the wild include additional releases of captive-bred animals with at least 75 percent Columbia Basin ancestry.

The draft recovery plan proposes a phased approach to recovery implementation: first, removal or abatement of imminent threats to prevent the extinction of the Columbia Basin pygmy rabbit; second, reestablishment of an appropriate number and distribution of free-ranging subpopulations over the near-term; and third, establishment and protection of a resilient, free-ranging population that could withstand foreseeable long-term threats. A key near-term objective of Federal recovery efforts is to reintroduce Columbia Basin pygmy rabbits to the wild and sufficiently reduce threats to the population to ensure a high probability of its persistence over the foreseeable future. The long-term recovery goal is to increase the number, distribution, and security of free-ranging Columbia Basin pygmy rabbits so that the population may be reclassified as threatened and, ultimately, be removed from the List of Endangered and Threatened Wildlife and Plants under the Act. The draft recovery plan identifies the following main actions as necessary to initiate recovery of the Columbia Basin pygmy rabbit: (1) Manage the captive breeding program; (2) manage genetic characteristics; (3) survey for and monitor free-ranging individuals; (4) reestablish free-ranging subpopulations within their historical distribution; (5) protect free-ranging individuals; (6) manage habitats at recovery emphasis areas to support stable, self-sustaining subpopulations; (7) pursue cooperative agreements with land owners and managers of intervening properties within the population's historical distribution; (8) exchange information with stakeholders and the general public to address concerns and increase support for recovery efforts; (9) secure funding for recovery efforts; and (10) revise the recovery plan as necessary to achieve the phased recovery strategy.

Public Comments Solicited

We solicit written comments on the draft recovery plan described in this notice. All comments received by the date specified above will be considered in development of a final recovery plan for the Columbia Basin pygmy rabbit.

Authority

The authority for this action is section 4(f) of the Endangered Species Act, 16 U.S.C. 1533 (f).

Dated: July 26, 2007.

David Wesley,

Acting Regional Director, Region 1, U.S. Fish and Wildlife Service.