The population of Columbia Basin pygmy rabbit is low and is designated as a Distinct Population Segment for protection under the U.S. Endangered Species Act. Conservation threats to the Columbian Basin pygmy rabbit include loss and degradation of shrubsteppe primarily due to conversion and fragmentation of this habitat to cropland for agriculture and development. Corridors of dense shrub cover connecting areas of suitable habitat are critical to recovery efforts.
Description and Range
The pygmy rabbit is the smallest rabbit species in North America. It can grow up to 11 inches long and weigh up to 16 ounces. It has a slate gray coloration that can turn brown during the summer months. Its ears are short and its tail is nearly invisible. Adult females are slightly larger than adult males.
Ecology and life history
Pygmy rabbits are sagebrush obligates, depending on this habitat for survival. Dense stands of sagebrush provide pygmy rabbits with year-round food and shelter. Native, perennial grasses and forbs provide an important food source beginning in spring and especially in summer and fall and deep, friable soils allow them to construct burrows.
The pygmy rabbit is one of only two North American rabbits known to dig its own burrows. Burrows are used for shelter, thermoregulation (to regulate body temperature), and safety from predators. Burrow systems are generally found on mounds or gentle slopes.
Big sagebrush is the primary food source, comprising 90 percent of the winter diet, but grasses and forbs are also eaten in spring and summer. Activity occurs throughout the year, and pygmy rabbits may be active any time of day or night (although most activity occurs during the twilight hours).
Breeding extends from Feb. to July. Specialized natal burrows, where females give birth to young, are excavated separate from residential burrows. Females have two to four litters per year with up to six kits per litter.
Predators include weasels, coyotes, American badgers, hawks, owls, and other carnivorous mammals and birds.
Pygmy rabbits inhabit sagebrush-dominated areas of the Great Basin in portions of Oregon, California, Nevada, Utah, Idaho, Montana, and Wyoming. The Washington population has been isolated from the remainder of the species' range for at least 10,000 years, and possibly as long as 40,000 to 115,000 years.
The Columbia Basin pygmy rabbit population is geographically and genetically discrete from the remainder of the taxon and this population is significant due to the unique ecological setting (i.e., geologic, climate, soil, and vegetation community) in which it occurs.
Museum specimen records and reliable sight records show that pygmy rabbits once occupied sagebrush habitat in Benton, Adams, Grant, Lincoln, and Douglas counties. Paleontological evidence suggest the species prehistorically had a broader distribution that also included Franklin, Kittitas, Chelan, Yakima, and Whitman counties.
By 2001, only one population remained at Sagebrush Flat Wildlife Area in Douglas County. See the Conservation section for WDFW's pygmy rabbit recovery effort.
The map illustrates potential range and habitat distribution of this species in Washington. For maps of worldwide distribution and other species' information, check out the International Union for Conservation of Nature - Red List and NatureServe Explorer.
Sensitivity to climate change
Pygmy rabbits inhabit shrub-steppe ecosystems and feed primarily on sagebrush throughout the year. This rabbit is predicted to undergo a major decline in geographic range as a result of climate change, which is expected to bring warmer, drier conditions, including drought, to Washington’s Columbia Basin where the species occurs. These conditions will lead to larger, more frequent, and hotter wildfires, thereby reducing the presence of sagebrush and encouraging the growth of cheatgrass and other invasive plants. Fires also contribute to fragmentation of existing habitat for the species. There are documented declines in pygmy rabbit populations following fires.
Exposure to climate change
- Increased temperatures
- Changes in precipitation
- Altered fire regimes
- Increased invasive plants
Conservation Threats and Actions Needed
- Fish and wildlife habitat loss or degradation
- Threat: Conversion of habitat to agriculture and development. Habitat fragmentation may hamper recovery efforts.
- Action Needed: Use landowner incentives, conservation easements, and U.S. Fish and Wildlife (USFWS) Safe Harbor Agreements to protect significant habitats. Coordinate with U.S. Department of Agriculture (USDA) Farm Service Agency (FSA), Natural Resources Conservation Service (NRCS), and USFWS. Recover species in the Columbia Basin through semi-wild breeding, releases, and translocations while working to recover habitat.
- Resource information collection needs
- Threat: Causes of the population decline in Washington are unknown, need to monitor status of reintroduced populations closely to determine any potential problems and adjust accordingly.
- Action Needed: Monitor reintroduced population for potential problems and success, and determine whether recovery actions are effective. Develop survey methods to efficiently detect long-distance dispersers from release site.
- Agriculture and aquaculture side effects
- Threat: Poorly-managed livestock grazing may cause degradation of shrubsteppe habitat (decreased quantity and quality of forage) and damage burrow systems.
- Action Needed: Use land acquisitions, conservation easements and landowner agreements to protect significant habitats. Coordination with Farm Service Agency (FSA).
- Threat: Old USDA Conservation Reserve Program (CRP) lands do not provide suitable habitat for the species.
- Action Needed: Smart grazing, fire management, and species population connectivity management programs can be beneficial for wildlife, livestock, and landowners. The department will also continue to engage USDA FSA and NRCS to encourage restoring old CRP habitat to native species through their various programs.
See the Climate vulnerability section above for information about the threats posed by climate change to this species.
Our Conservation Efforts
The Columbia Basin pygmy rabbit population is genetically distinct, considered to have been isolated for 10,000 years or longer from the rest of the pygmy rabbit population. Large-scale loss and fragmentation of shrubsteppe habitat were likely the primary factors contributing to decline, but once the population dropped below a certain threshold, other factors such as environmental events (extreme weather and fire), predation, disease, and inbreeding likely became threats.
A major recovery effort is underway for this species. In 2001, with as few as 16 pygmy rabbits known to exist in Washington, the WDFW and the USFWS initiated a captive breeding program with the intent of reintroducing rabbits to the wild, but none of the pygmy rabbits from the first release in 2007 survived beyond the first year. Since 2011, thousands of pygmy rabbits have been released into the wild on Sagebrush Flat Wildlife Area in Douglas County and on The Nature Conservancy Preserve in the Beezley Hills in Grant County as a result of collaborative recovery efforts between WDFW, USFWS, the Oregon Zoo, Washington State University, other state wildlife agencies, Northwest Trek, The Nature Conservancy in Washington, and Conservation Northwest.
Initially, pygmy rabbits were reintroduced to Washington through captive breeding of purebred Columbia Basin pygmy rabbits, but due to a lack of genetic diversity in the remnant population likely from inbreeding depression, rabbits were later intercrossed with pygmy rabbits from populations outside Washington. In 2015, the reintroductions failed in the Beezley Hills Recovery Area for unknown reasons and failed again in 2017 due to wildfire, but reintroductions in the Sagebrush Flat Recovery Area are re-establishing a small wild population.
The majority of the wild pygmy rabbit populations occur on private lands owned by farmers enrolled in the USDA’s Conservation Reserve Program. Biologists continue to closely monitor released pygmy rabbits to collect data on breeding, habitat use, survival, mortalities, and other factors to modify reintroduction techniques and manage the rabbit population.
- Washington State Recovery Plan for the Pygmy Rabbit (1995)
- 2019 Columbia Basin Pygmy Rabbit Reintroduction and Genetic Management Plan: Addendum to Washington State Recovery Plan for the Pygmy Rabbit (1995)
- Columbia Basin Pygmy Rabbit Recovery Report (2014)
- 2011 Columbia Basin Pygmy Rabbit Reintroduction and Genetic Management Plan: Addendum to Washington State Recovery Plan for the Pygmy Rabbit (1995)
- 2003 Update
- 2001 Update
- Amendment to the Draft Recovery Plan for the Columbia Basin Distinct Population Segment of the Pygmy Rabbit (USFWS - June 29, 2011)
- Periodic Status Review for the Pygmy Rabbit in Washington (2018)
- Status of the Pygmy Rabbit (Brachylagus idahoensis) in Washington (1993)