Brush Rabbit
Encyclopedia
The Brush Rabbit or Western 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.
vegetation
. It also occurs in oak and conifer habitats and it will live in brush or grassland, and form networks of runways through the vegetation. The Brush Rabbit does not dig its own burrow
or den
, but uses the burrow of other species
, brush piles, or forms. In the San Francisco Bay Area
, it was found that the Brush Rabbit concentrates its activities at the edge of brush and exhibits much less use of grassy areas. It uses the interior brush of the wilderness and it was also found that 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 season
s while grass
es are used in the wetter seasons in relation to growth of annual vegetation. Use of habitat
also probably is related to the breeding season.
varies from light brown to gray in color, while the underside is usually always white. Adult rabbits measure anywhere from 10-14 inches long and rarely weigh over two pounds.
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. Sylvilagus bachmani riparius, the Riparian Brush Rabbit, is highly endangered; 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
. 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 it's smaller size.
period of the Brush Rabbit female is about 22 days. A female Brush Rabbit can have as many as five litter
s per year but two to three is more common. One to seven young are born per litter and they are altricial
. The average number born per litter is three.
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. It is estimated the home ranges of the Brush Rabbit average just under 1 acres (4,046.9 m²) for males and just under 0.5 acres (2,023.4 m²) for females. The shape of these home ranges are usually circular but depending on the vegetation can be different in size and shape. Range use probably is not circular in shape or uniform, but rather consists of a series of runways that directly connect high use areas within brush habitat. Intraspecific socio-spatial 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 inter-individual distances of one to 24 feet (7.3 m) before aggressive chases occurred. It has been shown that females tended to not overlap while males showed relatively extensive overlapping and 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.
s, especially green clover
, though it will also take berries
and browse from bushes.
, fox
es, the Bobcat
, weasel
s, and various raptors
and snake
s. Its survival strategies include remaining immobile, when in brushy areas, and zig-zag running when found and/or in open spaces.
Cottontail rabbit
The cottontail rabbits are among the 16 lagomorph species in the genus Sylvilagus, found in the Americas.In appearance, most cottontail rabbits closely resemble the wild European Rabbit...
found in western coastal regions of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, from the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
to the southern tip of the Baja California peninsula
Baja California Peninsula
The Baja California peninsula , is a peninsula in northwestern Mexico. Its land mass separates the Pacific Ocean from the Gulf of California. The Peninsula extends from Mexicali, Baja California in the north to Cabo San Lucas, Baja California Sur in the south.The total area of the Baja California...
. Its range extends as far east as the eastern sides of the Sierra Nevada and Cascade
Cascade Range
The Cascade Range is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades...
mountain ranges.
Habitat
The Brush Rabbit inhabits dense, brushy cover, most commonly in chaparralChaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
vegetation
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
. It also occurs in oak and conifer habitats and it will live in brush or grassland, and form networks of runways through the vegetation. The Brush Rabbit does not dig its own burrow
Burrow
A burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...
or den
Den
Den may refer to:*Den , a part of a house similar to the living room: a den is about the size of a living room, but smaller than a family room*Den , a Ukrainian newspaper*Den , a Pharaoh of Egypt...
, but uses the burrow of other species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, brush piles, or forms. In the San Francisco Bay Area
San Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
, it was found that the Brush Rabbit concentrates its activities at the edge of brush and exhibits much less use of grassy areas. It uses the interior brush of the wilderness and it was also found that 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 season
Season
A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...
s while grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
es are used in the wetter seasons in relation to growth of annual vegetation. Use of habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
also probably is related to the breeding season.
Physical description
The Brush Rabbit is smaller than many of the other cottontails, and unlike most of them, the underside of its tail is grey rather than white (which may be why its common name does not include the word "cottontail"). The upperside of the Brush Rabbit's furFur
Fur is a synonym for hair, used more in reference to non-human animals, usually mammals; particularly those with extensives body hair coverage. The term is sometimes used to refer to the body hair of an animal as a complete coat, also known as the "pelage". Fur is also used to refer to animal...
varies from light brown to gray in color, while the underside is usually always white. Adult rabbits measure anywhere from 10-14 inches long and rarely weigh over two pounds.
Large numbers of geographically defined subspecies have been proposed, including in Oregon, ubericolor; in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, 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. Sylvilagus bachmani riparius, the Riparian Brush Rabbit, is highly endangered; formerly numerous along the San Joaquin River
San Joaquin River
The San Joaquin River is the largest river of Central California in the United States. At over long, the river starts in the high Sierra Nevada, and flows through a rich agricultural region known as the San Joaquin Valley before reaching Suisun Bay, San Francisco Bay, and the Pacific Ocean...
and Stanislaus River
Stanislaus River
The Stanislaus River in California is one of the largest tributaries of the San Joaquin River. The river is long and has north, middle and south forks...
, it is now reduced to a population of a few hundred in the Caswell Memorial State Park
Caswell Memorial State Park
Caswell Memorial State Park is a state park of California, USA, 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...
. 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 it's smaller size.
Reproduction
Brush Rabbit mating, as with other rabbits, may occur year-round but peak breeding seasons are between February and August. The gestationGestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period of the Brush Rabbit female is about 22 days. A female Brush Rabbit can have as many as five litter
Litter (animal)
A litter is the offspring at one birth of animals from the same mother and usually from one set of parents. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from...
s per year but two to three is more common. One to seven young are born per litter and they are altricial
Altricial
Altricial, meaning "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born...
. The average number born per litter is three.
Behavior
A trapping study of the Brush Rabbit in the Berkeley HillsBerkeley Hills
The Berkeley Hills are a range of the Pacific Coast Ranges that overlook the northeast side of the valley that surrounds San Francisco Bay. They were previously called the "Contra Costa Range/Hills" , but with the establishment of Berkeley and the University of California, the current usage was...
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. It is estimated the home ranges of the Brush Rabbit average just under 1 acres (4,046.9 m²) for males and just under 0.5 acres (2,023.4 m²) for females. The shape of these home ranges are usually circular but depending on the vegetation can be different in size and shape. Range use probably is not circular in shape or uniform, but rather consists of a series of runways that directly connect high use areas within brush habitat. Intraspecific socio-spatial 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 inter-individual distances of one to 24 feet (7.3 m) before aggressive chases occurred. It has been shown that females tended to not overlap while males showed relatively extensive overlapping and 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.
Food
The Brush Rabbit feeds mainly on grasses and forbForb
A forb is a herbaceous flowering plant that is not a graminoid . The term is used in biology and in vegetation ecology, especially in relation to grasslands and understory.-Etymology:...
s, especially green clover
Clover
Clover , or trefoil, is a genus of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes...
, though it will also take berries
Berry
The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....
and browse from bushes.
Predators and survival techniques
Its predators include the Cougar, the CoyoteCoyote
The coyote , also known as the American jackal or the prairie wolf, is a species of canine found throughout North and Central America, ranging from Panama in the south, north through Mexico, the United States and Canada...
, fox
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
es, the Bobcat
Bobcat
The bobcat is a North American mammal of the cat family Felidae, appearing during the Irvingtonian stage of around 1.8 million years ago . With twelve recognized subspecies, it ranges from southern Canada to northern Mexico, including most of the continental United States...
, weasel
Weasel
Weasels are mammals forming the genus Mustela of the Mustelidae family. They are small, active predators, long and slender with short legs....
s, and various raptors
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
and snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s. Its survival strategies include remaining immobile, when in brushy areas, and zig-zag running when found and/or in open spaces.