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You may download the complete reports by clicking the links below: Pygmy
Rabbit Recovery Plan 2003
Addendum:
In 1990, the Washington Wildlife Commission adopted procedures
for listing and delisting species as endangered, threatened, or sensitive
and for writing recovery and management plans for listed species (WAC
232-12-297, Appendix A). The procedures,
developed by a group of citizens, interest groups, and state and federal
agencies, require preparation of recovery plans for species listed as
threatened or endangered.
Recovery, as defined by the U.S. Fish and Wildlife Service,
is "the process by which the decline of an endangered or threatened species
is arrested or reversed, and threats to its survival are neutralized,
so that its long-term survival in nature can be ensured."
This document summarizes the historic and current distribution
and abundance of Pygmy Rabbits in Washington and describes factors affecting
the population and its habitat. It prescribes strategies to recover the
species, such as protecting the population, evaluating and managing habitat,
and initiating research and education programs. Target population objectives
and other criteria for reclassification are identified and an implementation
schedule is presented.
The draft state recovery plan was reviewed by researchers
and state and federal agencies. This review was followed by a 90-day public
comment period. All comments received were considered in this final recovery
plan. Additional information on Pygmy Rabbits is available from:
Endangered Species Section Manager |
Pygmy Rabbit
Recovery Plan: [ 2003 Addendum ] [ 2001 Addendum ] The pygmy rabbit (Brachylagus idahoensis) is the smallest rabbit in North America. It is patchily distributed in the sagebrush-dominated areas of the Great Basin. This includes portions of Oregon, California, Nevada, Utah, Idaho, Montana, Wyoming, and Washington. Washington populations are disjunct from the core of the species' range, apparently separated for thousands of years. Paleontological evidence suggests that the species had a broader distribution in Washington thousands of years ago. Today, the known Washington range of the pygmy rabbit is greatly restricted. Museum specimen records and reliable sight records show that pygmy rabbits formerly occupied sagebrush habitat in five Washington counties: Benton, Adams, Grant, Lincoln, and Douglas. Currently, pygmy rabbits are known to survive in five isolated fragments of suitable habitat in Douglas County. The current Washington population is estimated to be fewer than 250 rabbits. Of the five pygmy rabbit areas known to remain in Washington, the largest may be comprised of fewer than 150 rabbits. The other four populations are significantly smaller. In 1990, the pygmy rabbit was listed as a threatened species by the Washington Wildlife Commission. The Commission reclassified the species to endangered in 1993. It is listed as a Candidate Category 2 species by the U.S. Fish and Wildlife Service. The pygmy rabbit is the only rabbit native to North America that digs its own burrows. It is also uniquely dependent upon sagebrush, which comprises up to 99% of its winter diet. Dense sagebrush and relatively deep, loose soil are important characteristics of pygmy rabbit habitat. The primary factor contributing to the decline of the pygmy rabbit in Washington has been loss of habitat due to agricultural conversion. Because of low numbers and limited distribution, pygmy rabbit populations in Washington are vulnerable to fire, disease, intense predation, and the random variation in birth and death rates, sex ratios, and combinations of demographic parameters that sometimes cause the collapse of small populations. Habitat degradation and loss are likely to continue without active prevention efforts. Before the pygmy rabbit can be considered at low risk of extirpation in Washington, numbers and distribution must be increased. In addition, adequate habitat must be managed for the long-term protection of features that support pygmy rabbits. The recovery objectives for downlisting from State Endangered status are a minimum population of 1400 adult pygmy rabbits comprised of at least two areas supporting at least 500 adult pygmy rabbits and four additional areas that support at least 100 adult pygmy rabbits. All of the areas must be in secure habitat with long-term management plans in place which conserve pygmy rabbits and their habitat. The recovery objectives for delisting from State Threatened status are a minimum population of 2800 adult pygmy rabbits comprised of at least four areas supporting at least 500 adult pygmy rabbits and eight additional areas with at least 100 adult pygmy rabbits. All of these areas must be in secure habitat with long-term management plans in place. Recovery strategies for this species include protection of existing habitat, identification and management of lands for creation of new habitat, monitoring of the pygmy rabbit population, and research to better understand the effects of management actions. Grazing, if it occurs in pygmy rabbit areas, should be managed to be compatible with pygmy rabbit habitat needs. In all pygmy rabbit areas, steps should be taken to reduce the risk of range fire. To increase the extent of pygmy rabbit habitat, efforts should be directed at identifying lands where soil conditions are suitable for pygmy rabbits. If necessary, lands with appropriate soil conditions should be restored or enhanced to provide pygmy rabbit habitat. Pygmy rabbits should be introduced to selected vacant habitat. Other strategies, including enforcement, data management, cooperative work with landowners and other agencies, research, and public information should all play a role in pygmy rabbit recovery efforts. May
2003 Addendum: Executive Summary This document summarizes 2002 recovery efforts for the Columbia Basin pygmy rabbit, and outlines new tasks to be completed in 2003. The initial (1995) Washington State Recovery Plan for the Pygmy Rabbit was updated with the 2001 Addendum, Emergency Measures for Species Survival. This is the second addendum to the 1995 recovery plan. The pygmy rabbit was listed as a threatened species in the state in 1990 and was reclassified to endangered status in 1993. It was listed under emergency provisions of the federal Endangered Species Act in November 2001 by the U.S. Fish and Wildlife Service, with a final rule continuing the endangered listing in March 2003. A state recovery plan for the rabbit was written in 1995. Recovery objectives are to increase pygmy rabbit numbers and distribution and manage habitat for long-term protection of features that support pygmy rabbits. Less than 30 Columbia Basin pygmy rabbits are believed to remain in the wild. A captive breeding program was initiated in 2001. The captive breeding program is a cooperative project involving the WDFW (lead agency), and Washington State University, the Oregon Zoo, and Northwest Trek Wildlife Park, where captive breeding occurs. The 2002 breeding season was the first breeding season for Columbia Basin pygmy rabbits. Eighteen rabbits were paired beginning in early March, but breeding did not occur until mid-April. The first litters were born between May 1 and 3. Of 12 different pairings at Washington State University, only two produced young. One of the pairs produced stillborn young and the other pair produced 5 young. One re-pairing later in the spring produced only stillborn young. At the Oregon Zoo, eight pairings were attempted with only two pairings producing a total of 10 young. Re-matings were not successful, with one re-mating producing two stillborn young. A total of fifteen young Columbia Basin pygmy rabbits were born in 2002, but disease in the captive population, most notably avian tuberculosis, eliminated numerical gains in the captive population and reduced genetic diversity. Additional recovery efforts included rearing and releasing captive Idaho pygmy rabbits back into Idaho as an experiment, to test and improving release methods. A total of 20 Idaho pygmy rabbits born in captivity in 2002 were released in two groups at the Idaho National Environmental Engineering Laboratory near Idaho Falls, Idaho. The first group of 13 rabbits was released August 9 and the second group of 7 was released September 16. Four rabbits survived to breeding season 2003. Plans for 2003 are for a similar experiment to further test release methods. Funds for habitat acquisition were secured in 2003, which could potentially assist in developing a second release site for pygmy rabbits. Surveys conducted during winter 2001-2002 at Sagebrush Flat Wildlife Area located located 23 active burrows in three general areas. Visitation to these three areas during the winter of 2002-2003 found active burrows in one of the three general areas. Surveys of potential habitat continued in 2002 by both WDFW and the Bureau of Land Management, but no new pygmy rabbits were found. Genetic analyses indicate that genetic drift has occurred in the captive population, resulting in a significant decline in genetic diversity. New initiatives for 2003 include conducting experimental cross-breeding of pygmy rabbits from the Columbia Basin with those from Idaho, expanding captive breeding facilities at Northwest Trek Wildlife Park, and developing agreements with private landowners to survey for other pygmy rabbits in the wild.
August 2001 Addendum: Executive Summary
This document summarizes the current status of pygmy rabbits in Washington,
reassesses and prioritizes the strategies and tasks of the initial (1995)
Washington State Recovery Plan for the Pygmy Rabbit
and provides an overview of emergency measures needed to prevent extinction
of Washington's pygmy rabbit.
The pygmy rabbit was listed as a threatened species in the state in 1990
and was reclassified to endangered status in 1993. It is a U.S. Fish and
Wildlife Service species of concern. A state recovery plan for the rabbit
was written in 1995 and efforts have been underway to implement the plan
despite less than full funding. Recovery objectives are to increase pygmy
rabbit numbers and distribution and manage habitat for long-term protection
of features that support pygmy rabbits.
The number of populations and numbers of pygmy rabbits have been declining
since 1997. In 1995, five pygmy rabbit populations were known to exist
in Douglas County and a sixth population was found in 1997. Between 1997-2000
five of the six populations disappeared; by March 2001, only one area,
Sagebrush Flat, was known to still have rabbits. Small populations at
several sites were extirpated for unknown reasons, other populations were
extirpated by known wildfires. Numbers of active burrows on standardized
plots at Sagebrush Flat have declined from 229 in 1995 to zero in 2001.
Random searches did reveal some active burrows at Sagebrush Flat in March
and April 2001.
Genetic analyses of pygmy rabbits in Montana, Idaho, Oregon, and Washington
have confirmed that the Washington population of pygmy rabbit is distinct
and isolated from the rest of the species' range, and has been separated
for thousands of years. These genetic differences more likely than not
are similar to subspecific differences recognized in other mammals. Extinction
of the Washington pygmy rabbit subspecies or race may occur at any time.
The small remaining population is susceptible to disease, predation, and
stochastic events.
With the apparent collapse of the pygmy rabbit population in the wild,
the Department evaluated a number of options. Leaving a few remaining
rabbits in the wild would encumber the population with extreme risk. There
was only one option available to maintain the unique Washington pygmy
rabbit - that was to initiate a captive breeding program to raise and
release Washington pygmy rabbits. A decision was made by the Department
in May 2001 to collect rabbits from the wild to begin a captive breeding
program. The goal is to develop a captive population to ensure the maintenance
of Washington's unique pygmy rabbits and to reintroduce sufficient numbers
of captive-bred rabbits to re-establish populations in suitable habitat.
Eleven of the remaining pygmy rabbits in Washington were captured and
translocated to Washington State University. In addition, one female gave
birth to 5 young in captivity.
The captive breeding program will begin with a cooperative project involving
the WDFW (lead agency), Washington State University (where captive breeding
will occur), the Oregon Zoo (where husbandry techniques are being developed),
and Northwest Trek Wildlife Park. Other zoos may also be solicited to
house small numbers of captive animals. A project biologist will be hired
to conduct the captive rearing, release, and monitoring phases of the
project. They will annually report on production, release and post-release
survival phases of the project. Pygmy rabbits will be reintroduced into
suitable habitat, provided with artificial burrows, and protected from
predators with electric fencing. A Science Advisory Group will review
all aspects of the project. Cost of a 3-year program is expected to be
approximately $700,000 - 750,000. Long-term options will depend upon the
success of the program.
For more information on wildlife management issues, please contact WDFW Wildlife Management Program. Phone: 360-902-2515
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