Brush rabbit

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Brush rabbit [1]
Sylvilagus bachmani 01035t.JPG
Brush rabbit (Finley National Wildlife Refuge)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Lagomorpha
Family: Leporidae
Genus: Sylvilagus
Species:
S. bachmani
Binomial name
Sylvilagus bachmani
(Waterhouse, 1839)
Subspecies
Brush Rabbit area.png
Brush rabbit range

The brush rabbit (Sylvilagus bachmani), or western brush rabbit, or Californian brush rabbit, [3] 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.

Contents

Description and taxonomy

Brush rabbit American Rabbit.jpg
Brush rabbit

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 30.3 to 36.9 cm (11.9 to 14.5 in) in length, and range in weight from 511 to 917 g (1.127 to 2.022 lb). [4]

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. [1]

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 burrows made by other species, but does not dig its own. The home range is very small, less than 2,000 m2 (22,000 sq ft). [5]

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. [5]

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. [4]

The brush rabbit feeds mainly on grasses and forbs, especially green clover. It also eats berries and browses on shrubs. [4]

A trapping study of the brush rabbit in the Berkeley Hills 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 4,000 square meters (1 acre) for males and just under 2,000 square meters (0.5 acres) 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 0.3 to 7.3 meters (1 to 24 ft) 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. [4] The gestation period of the brush rabbit is about 22 days, and kits are altricial. Male brush rabbits breed from around October to November through June to July. The brush rabbit's most reproductive activity occurs from January to April. In the areas of San Francisco, pregnant female brush rabbits can be found from the first week of December until the ends of June. Female brush rabbits have about four litters per year. [6]

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. [4]

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 by the United States Fish and Wildlife Service. [7] 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. [8] This population has been negatively impacted by the destruction of the riparian habitat. [9] 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. [10]

Subspecies

Three geographic subspecies of the brush rabbit are acknowledged as follows. [11]

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. [11] It is also found in the Sacramento Valley. [11]

The subspecies is medium in size, paler in color, has larger ears and shorter hind feet. [11]

Sylvilagus bachmani macrorhinus

This subspecies of Sylvilagus bachmani is geographically found in west-central California—from San Francisco to the north end of Monterey Bay and inland from Solano County south to Santa Clara County. [11]

It is smaller in size but has longer ears. [11]

Sylvilagus bachmani riparius

This subspecies of Sylvilagus bachmani is geographically found on the west side of the San Joaquin River in northern Stanislaus and southern San Joaquin counties. This subspecies is pale and gray-sided. [11]

Sylvilagus bachmani riparius is listed as an endangered species both by California and federally, primarily due to habitat destruction. In the San Joaquin Valley, over 93% of the habitat was destroyed for urban and agricultural use. [12] A population of riparian brush rabbits has moved into restored habitat in the new Dos Rios State Park. [13]

Related Research Articles

<span class="mw-page-title-main">Leporidae</span> Family of lagomorphs

Leporidae is the family of rabbits and hares, containing over 70 species of extant mammals in all. The Latin word Leporidae means "those that resemble lepus" (hare). Together with the pikas, the Leporidae constitute the mammalian order Lagomorpha. Leporidae differ from pikas in that they have short, furry tails and elongated ears and hind legs.

<span class="mw-page-title-main">Desert cottontail</span> Species of mammal

The desert cottontail, also known as Audubon's cottontail, is a New World cottontail rabbit, and a member of the family Leporidae. Unlike the European rabbit, they do not form social burrow systems, but compared with some other leporids, they are extremely tolerant of other individuals in their vicinity.

<span class="mw-page-title-main">Cottontail rabbit</span> Genus of mammals

Cottontail rabbits are in the Sylvilagus genus, which is in the Leporidae family. They are found in the Americas. Most Sylvilagus species have stub tails with white undersides that show when they retreat, giving them their characteristic name. However, this feature is not present in all Sylvilagus, nor is it unique to the genus.

<span class="mw-page-title-main">Swamp rabbit</span> One of the only two semiaquatic lagomorphs, along with the marsh rabbit

The swamp rabbit, also called the cane-cutter, is a large cottontail rabbit found in the swamps and wetlands of the southern United States. The species has a strong preference for wet areas, and it will take to the water and swim.

<span class="mw-page-title-main">Eastern cottontail</span> Species of mammal

The eastern cottontail is a New World cottontail rabbit, a member of the family Leporidae. It is the most common rabbit species in North America.

<span class="mw-page-title-main">Pygmy rabbit</span> Species of mammal

The pygmy rabbit is a rabbit species native to the United States. It is also the only native rabbit species in North America to dig its own burrow. The pygmy rabbit differs significantly from species within either the Lepus (hare) or Sylvilagus (cottontail) genera and is generally considered to be within the monotypic genus Brachylagus. One isolated population, the Columbia Basin pygmy rabbit, is listed as an endangered species by the U.S. Federal government, though the International Union for Conservation of Nature lists the species as lower risk.

<span class="mw-page-title-main">Common tapeti</span> Species of mammal

The common tapeti, also known as the Brazilian cottontail, forest cottontail, or (formerly) simply tapeti is a species of cottontail rabbit. It is small to medium-sized with a small, dark tail, short hind feet, and short ears. As traditionally defined, its range extends from southern Mexico to northern Argentina, but this includes several distinctive population that have since been split into separate species. Under this narrower definition, the true common tapeti only occurs in the Atlantic Rainforest of coastal northeastern Brazil and it is classified as "Endangered" by the IUCN. The American Society of Mammalogists concurs, but also tentatively classifies several distinct populations that have not yet received proper species names into S. brasiliensis, and thus considers it to range from Venezuela south to Argentina.

<span class="mw-page-title-main">Omilteme cottontail</span> Species of mammal

The Omilteme cottontail is a cottontail rabbit found only in the state of Guerrero, Mexico in the mountain range of Sierra Madre del Sur. Belonging to the family Leporidae, it is one of fourteen species in the genus Sylvilagus, a genus restricted to the New World. The Omilteme cottontail is considered one of the most endangered rabbit species in the world and is only known and been described by very few specimens.

<span class="mw-page-title-main">New England cottontail</span> Species of mammal

The New England cottontail, also called the gray rabbit, brush rabbit, wood hare, wood rabbit, or cooney, is a species of cottontail rabbit represented by fragmented populations in areas of New England and the state of New York, specifically from southern Maine to southern New York. This species bears a close resemblance to the eastern cottontail, which has been introduced in much of the New England cottontail home range. The eastern cottontail is now more common in it.

<span class="mw-page-title-main">Mexican cottontail</span> Species of mammal

The Mexican cottontail is a species of cottontail rabbit in the family Leporidae. It is endemic to Mexico where its natural habitats are temperate forests, subtropical or tropical dry forests and pastureland.

<span class="mw-page-title-main">Dice's cottontail</span> Species of mammal

Dice's cottontail is a species of cottontail rabbit in the family Leporidae. It is found in Costa Rica and Panama, in páramo and cloud forest habitats.

<span class="mw-page-title-main">San José brush rabbit</span> Species of mammal

The San José brush rabbit is a critically endangered subspecies of the brush rabbit, in the family Leporidae.

<span class="mw-page-title-main">Mountain cottontail</span> Species of mammal

The mountain cottontail or Nuttall's cottontail is a species of mammal in the family Leporidae. It is found in Canada and the United States.

<span class="mw-page-title-main">Appalachian cottontail</span> Species of mammal

The Appalachian cottontail is a species of cottontail rabbit in the family Leporidae. It is a rare species found in the upland areas of the eastern United States.

<span class="mw-page-title-main">Marsh rabbit</span> Species of mammal

The marsh rabbit is a small cottontail rabbit found in marshes and swamps of coastal regions of the Eastern and Southern United States. It is a strong swimmer and found only near regions of water. It is similar in appearance to the eastern cottontail but is characterized by smaller ears, legs, and tail.

The San Luis National Wildlife Refuge Complex is located in the northern San Joaquin Valley, within Merced County and Stanislaus County of California. The complex, with four federal National Wildlife Refuges, is managed by the U.S Fish & Wildlife Service.

<span class="mw-page-title-main">Robust cottontail</span> Species of mammal

The robust cottontail or Holzner's cottontail is a species of cottontail rabbit native to high-altitude regions of the southwestern United States and western Mexico.

<span class="mw-page-title-main">San Joaquin River National Wildlife Refuge</span> Wildlife refuge in California, US

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.

<span class="mw-page-title-main">Caswell Memorial State Park</span> State park in California, United States

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 this park, is threatened and the park is trying to protect it. It once flourished through California's Central Valley. Caswell is also the home to several endangered species. The 258-acre (104 ha) park was established in 1952.

Smith Island cottontail, Smith's Island cottontail or Hitchen's cottontail, was a subspecies of the Eastern cottontail rabbit that lived mainly on two islands on the tip of the Delmarva Peninsula in Virginia. It is generally considered to be extinct.

References

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  7. "Riparian brush rabbit (Sylvilagus bachmani riparius)". U.S. Fish & Wildlife Service. Retrieved 12 August 2019.
  8. Sommer, Lauren (May 4, 2023). "The latest to be evacuated from California's floods? Bunnies". NPR News.
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