The brush rabbit (Sylvilagus bachmani), or western brush rabbit, or Californian brush rabbit, is a species of cottontail rabbit found in western coastal regions of North America, from the Columbia River in Oregon to the southern tip of the Baja California Peninsula. Its range extends as far east as the eastern sides of the Sierra Nevada and Cascade mountain ranges.
Description and taxonomy
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The brush rabbit is a small rabbit with short legs and a short tail. It is dark gray on the sides and back, and pale gray on the belly and the underside of the tail. The whiskers are mostly black, although some have white tips. Adult rabbits measure anywhere from in length, and range in weight from .
Large numbers of geographically defined subspecies have been proposed, including in Oregon, ubericolor; in California, cinerascens, mariposae, riparius, tehamae and trowbridgii; and in Baja California, cerrosensis, exiguus, howelli, peninsularis and rosaphagus. Subspecies bachmani, macrorhinus and virgulti are less geographically restricted. Of the various proposed subspecies, only the following are currently recognized, the others are synonyms: S. b. ubericolor, S. b. cinerascens, S. b. bachmani, S. b. exiguus, S. b. howelli, S. b. cerrosensis.
Brush rabbits most commonly live in chaparral vegetation, but are also found in oak and conifer habitats. In the San Francisco Bay Area, the brush rabbit was found to concentrate its activities at the edge of brush and exhibits much less use of grassy areas. It uses the interior brush of the wilderness, and this may be a better environment for it than the chaparral one. Studies done on the brush rabbit in Oregon also showed that it rarely left the brushy areas it inhabits. Brush may be used more in the drier seasons, while grasses are used in the wetter seasons in relation to growth of annual vegetation. Use of habitat also probably is related to the breeding season.
Distribution
The brush rabbit is confined to the Pacific Coast, from the Columbia River in the north to the tip of Baja, Mexico in the south. It does not occur east of the Sierra Nevada and Cascade Mountain ranges.
Predators and survival techniques
Its predators include cougar, coyote, fox, bobcat, weasel, and various raptors and snakes. Its survival strategies include remaining immobile when in brushy areas, and zig-zag running when found in open spaces. It also climbs onto low branches to escape from predators and other perceived threats. Formerly numerous along the San Joaquin River and Stanislaus River, it is now reduced to a population of a few hundred in the Caswell Memorial State Park and is being reintroduced to the adjacent San Joaquin River National Wildlife Refuge in the San Joaquin Valley, California. This population has been negatively impacted by the destruction of the riparian habitat. Another subspecies, the San José brush rabbit, is considered critically endangered.
Myxomatosis
Brush rabbits are a natural carrier of the myxoma virus, a poxvirus in the genus Leporipoxvirus. This virus causes only a mild disease in brush rabbits, but causes a severe and usually fatal disease called myxomatosis in European (pet) rabbits. The disease is usually transmitted from one rabbit to another by biting insects.
Subspecies
Three geographic subspecies of the brush rabbit are acknowledged as follows.
Sylvilagus bachmani tehamae
This subspecies of Sylvilagus bachmani is geographically found from the Rogue River Valley, Jackson County, Oregon, through Northern California, along the inner coast ranges, to southern Lake County and along the Sierra Nevada to Placer County. A population of riparian brush rabbits has moved into restored habitat in the new Dos Rios State Park.