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 The Columbia River (Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, C ...

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 The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

and

Cascade Cascade, Cascades or Cascading may refer to: Science and technology Science *Cascade waterfalls, or series of waterfalls * Cascade, the CRISPR-associated complex for antiviral defense (a protein complex) * Cascade (grape), a type of fruit * Bioc ...

mountain ranges.

Description and taxonomy

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''. It has been noted that numbers of the eastern cottontail were brought west to reproduce and provide a food source for the settlers. The interbreeding of the two species has occurred where the brush rabbit has in parts of Oregon developed the white cottontail although retaining its smaller size.

Habitat and ecology

Brush rabbits require dense bramble clumps or other thick, brushy habitat. These bramble clumps often have extensive networks of trails and runways. The species occasionally uses

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

s made by other species, but does not dig its own. The home range is very small, less than . Brush rabbits most commonly live in

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

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 Breeding is sexual reproduction that produces offspring, usually animals or plants. It can only occur between a male and a female animal or plant. Breeding may refer to: * Animal husbandry, through selected specimens such as dogs, horses, and rab ...

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.

Behavior

Brush rabbits forage alone or in small groups. They can be seen sunning in the mid-morning, but are otherwise secretive and wary. They thump the ground with their back feet when startled. The brush rabbit feeds mainly on grasses and forbs, especially green clover. It also eats berries and browses on shrubs. A trapping study of the brush rabbit in the

Berkeley Hills The Berkeley Hills are a range of the Pacific Coast Ranges that overlook the northeast side of the valley that encompasses San Francisco Bay. They were previously called the "Contra Costa Range/Hills" (from the original Spanish ''Sierra de la C ...

in Northern California indicated that males had larger home ranges than females at all times of the year, and especially in May when females were moving the least. The home ranges of the brush rabbit are estimated to average just under for males and just under for females. The shapes of these home ranges are usually circular, but depending on the vegetation, can differ in size and shape. Range use probably is not circular in shape or uniform, but rather consists of a series of runways that directly connects high-use areas within brush habitat. Intraspecific sociospatial behavior appears to be variable and may reflect local resource conditions. Several rabbits have been observed to feed in the same area simultaneously, but maintained interindividual distances of before aggressive chases occurred. Females tended to not overlap, while males showed relatively extensive overlapping; this may indicate that females are territorial. Groups of brush rabbits may serve social purposes, such as predator detection, but this has not been proven.

Reproduction

The brush rabbit's breeding season varies from north to south. In Oregon, breeding begins in February and ends in August, while in California it begins in December and ends in May or June. Litter size also varies between regions. Studies have found the average litter size in Oregon to be 2.8, in northern and central California to be 3.5, and in west central California to be 4.0. The brush rabbit is one of the less fecund members of the genus, producing about 15 young in five to six litters per year. The

gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...

period of the brush rabbit female is about 22 days, and kits are altricial.

Predators and survival techniques

Its predators include

cougar The cougar (''Puma concolor'') is a large Felidae, cat native to the Americas. Its Species distribution, range spans from the Canadian Yukon to the southern Andes in South America and is the most widespread of any large wild terrestrial mamm ...

coyote The coyote (''Canis latrans'') is a species of canis, canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecologica ...

fox Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush''). Twelve sp ...

bobcat The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the IUC ...

, 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.

Human interaction and conservation status

The brush rabbit is not hunted as are many other cottontail species, probably because of its small size. It is not a major cause of damage to crops or other human developments in its habitat. While the overall population of brush rabbits is stable, one of its subspecies, the riparian brush rabbit (''S. b. riparius''), is listed as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

by the United States Fish and Wildlife Service. Formerly numerous along the San Joaquin River and

Stanislaus River The Stanislaus River is a tributary of the San Joaquin River in north-central California in the United States. The main stem of the river is long, and measured to its furthest headwaters it is about long. Originating as three forks in the high ...

, it is now reduced to a population of a few hundred in the

Caswell Memorial State Park Caswell Memorial State Park is a state park of California, United States, preserving a riparian forest along the Stanislaus River. It is located in southern San Joaquin County southwest of the town of Ripon. Riparian Oak Woodland, located in th ...

and is being reintroduced to the adjacent

San Joaquin River National Wildlife Refuge The San Joaquin River National Wildlife Refuge is a protected area of along the San Joaquin River in the northern San Joaquin Valley, California. It is within San Joaquin County and Stanislaus County. It protects more than of riparian woodlan ...

in the San Joaquin Valley, California. This population has been negatively impacted by ongoing riparian habitat destruction. Another subspecies, the

San José brush rabbit The San José brush rabbit (''Sylvilagus bachmani mansuetus'') is a critically endangered subspecies of the brush rabbit, in the family Leporidae. Taxonomy It was formerly thought to be its own species, but more recent studies indicate that i ...

, is considered critically endangered.

Myxomatosis

Brush rabbits are a natural carrier of the '' myxoma virus'', a poxvirus in the genus ''

Leporipoxvirus ''Leporipoxvirus'' is a genus of viruses, in the family ''Poxviridae'', in the subfamily ''Chordopoxvirinae''. Lagomorphs and squirrels serve as natural hosts. There are four species in this genus. Diseases associated with this genus include: m ...

''. This virus causes only a mild disease in brush rabbits, but causes a severe and usually fatal disease called

myxomatosis Myxomatosis is a disease caused by ''Myxoma virus'', a poxvirus in the genus ''Leporipoxvirus''. The natural hosts are tapeti (''Sylvilagus brasiliensis'') in South and Central America, and brush rabbits (''Sylvilagus bachmani'') in North Ame ...

in European (pet) rabbits. The disease is usually transmitted from one rabbit to another by biting insects.

References

{{Taxonbar, from=Q1508885

Brush rabbit 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 ...

Mammals of Mexico Mammals of the United States Fauna of the California chaparral and woodlands Fauna of the Sierra Nevada (United States) Fauna of the Baja California Peninsula

Taxa named by George Robert Waterhouse