Oregon populations of the pygmy rabbit are listed as a species of concern under the Endangered Species Act.  (In 2003, a Distinct Population Segment of the pygmy rabbit in Washington was listed as endangered.) After completing a 12-month status review in September 2010, the USFWS concluded the pygmy rabbit does not warrant Endangered Species Act protection.

Historical Status and Current Trends

The pygmy rabbit’s historical range includes portions of Washington, Oregon, Idaho, Montana, Wyoming, California, Nevada, and Utah.  Currently in Oregon, pygmy rabbits are found in several eastern Oregon counties, although biologists are unsure about the number of rabbits in the wild.  On March 5, 2003, the Columbia Basin pygmy rabbit (considered a Distinct Population Segment), was listed as endangered in Washington State.

Habitat

Pygmy rabbits are typically found in areas that include tall, dense stands of sagebrush (Artemisia spp.), and are highly dependent on sagebrush to provide both food and shelter throughout the year.  During winter months the rabbits' diet consists of up to 98 percent sagebrush.  In the summer and spring months, their diet becomes more varied, including more grass and new foliage. 

The pygmy rabbit digs its own burrows, which are typically found in deep, loose soils. However, pygmy rabbits occasionally make use of burrows abandoned by other species and, as a result, may occur in areas of shallower or more compact soils that support sufficient shrub cover.

Life History

The pygmy rabbit is unique enough to have its own genus, Brachylagus.  Weighing less than a pound (.45 kilograms), pygmy rabbits are the smallest rabbit in North America and can easily fit in the palm of a hand. Ffur color varies from brown to dark grey with white around the margins of their short, round ears. The rabbits' ears and feet are densely covered in hair and they have a very short tail.  Several traits set them apart from cottontails (Sylvilagus) and jackrabbits (Lepus).  Pygmies are the only North American rabbits that dig their own burrows, and they subsist almost entirely on sagebrush. They also give alarm calls and other vocalizations, indicating some degree of sociality. 

Pygmy rabbits breed in early spring, having up to three litters per year and averaging six young per litter.  Recent information on captive and wild pygmy rabbits indicates that pregnant females dig secret, relatively shallow burrows, known as natal burrows.  These natal burrows are found in the vicinity of the pygmy rabbit’s regular burrows, which are used to give birth in and for nursing and early rearing of their litters.

Pygmy rabbits are preyed upon by weasels, coyotes, badgers, bobcats, birds of prey, owls, foxes, and sometimes humans (pygmy rabbits are sometimes difficult for hunters to distinguish from other rabbit species).  Predation is the primary cause of mortality among both adults and juveniles and can be as high as 50 percent in the first five weeks of life.  Like other rabbits, pygmy rabbits mainly try to stay hidden and are cryptically colored to avoid predation. They are also capable of short bursts of speed to try and escape predators.

Reasons for Decline

Loss of sagebrush, upon which pygmy rabbits are highly dependent for food and shelter, is the main reason for the decline of pygmy rabbit populations. Much sagebrush has been burned or converted to agriculture. Sagebrush is often cleared from large areas and replaced with exotic bunch grasses to improve livestock forage.  Wildfires and invasive plants also pose a threat to the rabbits' habitat.

Conservation Measures

Currently, the U.S. Fish and Wildlife Service is conducting a study to determine if pygmy rabbits should be protected under the Endangered Species Act (see Federal Register Notice below).  In addition, the Oregon Zoo is breeding pygmy rabbits which will be reintroduced to protected habitats in eastern Oregon.

References

Federal Register Notice: Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Pygmy Rabbit (Brachylagus idahoensis) as Threatened or Endangered January 8, 2008.