FWS Focus

Overview

Characteristics
Overview

Brown and white with a fuzzy cottontail, the riparian riparian
Definition of riparian habitat or riparian areas.

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brush rabbit is a subspecies of the more common brush rabbit which is found in Oregon, California and Baja California, Mexico. It’s a small rabbit; full-grown adults measure about 12 inches in length and weigh just 1.5 pounds. 

The riparian brush rabbit was once believed to be reduced to a single population in Caswell Memorial State Park, but another population was discovered near Lathrop, California, in 1998. Since this discovery, a third population has been reintroduced to the San Joaquin River National Wildlife Refuge. While recovery efforts are underway for the species, the rabbit is among the rarest mammals in the state. It was listed as endangered on February 23, 2000. 

The biggest current threat to the species is a fatal virus that infects rabbits across the western United States. The U.S. Fish and Wildlife Service is working with partners to vaccinate rabbits against the virus. Other threats to the species include seasonal flooding of habitat, development and land use change, wildfire, drought and predation.

Scientific Name

Sylvilagus bachmani riparius
Common Name
Riparian Brush Rabbit
FWS Category
Mammals
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Life Cycle

Characteristics
Life Span

If they survive their first year of life, riparian riparian
Definition of riparian habitat or riparian areas.

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brush rabbits can live for three or more years in the wild. 

Reproduction

Riparian brush rabbits typically breed from January to May. Females can have multiple litters per year, with three to four young per litter. Gestation is approximately 27 days. Brush rabbits use nests for birthing and raising neonates for approximately two weeks after birth. Riparian brush rabbit nests are rarely observed, because nests are typically hidden within large clumps of dense, and often thorny, vegetation. Young rabbits typically leave the nest at two weeks of age. The riparian riparian
Definition of riparian habitat or riparian areas.

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brush rabbit reaches adult size approximately 77 to 84 days after birth.

Characteristic category

Habitat

Characteristics
Habitat

Habitat for the riparian riparian
Definition of riparian habitat or riparian areas.

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brush rabbit consists of riparian areas that contain willow thickets (Salix spp.), California wild rose (Rosa californica), Pacific blackberry (Rubus vitifolius), wild grape (Vitis californica), Douglas' coyote bush (Baccharis douglasii) and various grasses. The rabbits have small home ranges that are limited by the size of available brushy habitat. 

River or Stream

A natural body of running water.

Rural

Environments influenced by humans in a less substantial way than cities. This can include agriculture, silvaculture, aquaculture, etc.

Wetland

Areas such as marshes or swamps that are covered often intermittently with shallow water or have soil saturated with moisture.

Characteristic category

Food

Characteristics
Food

The riparian riparian
Definition of riparian habitat or riparian areas.

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brush rabbit frequents small clearings, where they feed on a variety of vegetation. They feed upon native and non-native grasses and herbs like creeping wild rye (Leymus triticoides), non-native peppergrass (Lepidium spp.), mugwort (Artemisia douglasiana), Santa Barbara sedge (Carex barbarae), stinging nettle (Urtica dioica) and gumplant (Grindelia camporum). Particularly during the dry season, when more desirable food plants are unavailable, they also eat a variety of plant material from woody species that include wild rose, blackberry, elderberry, wild grape and oak.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The riparian riparian
Definition of riparian habitat or riparian areas.

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brush rabbit is a medium to small cottontail rabbit. Its body color varies from dark brown to gray, with a white belly. When viewed from above, its cheeks protrude outward rather than being straight or concave, as in the other brush rabbit subspecies. The riparian brush rabbit can be distinguished from desert cottontails by their smaller tail and uniformly colored ears, being that they do not have black tips.

Measurements
Length: 11 to 13 in (300 to 375 mm)
 

Weight

Weight: 1 to 2 lbs (500 to 800 gm)

Color & Pattern

Brown and white with a fuzzy cottontail.

Geography

Characteristics
Range

Today, the riparian riparian
Definition of riparian habitat or riparian areas.

Learn more about riparian
brush rabbit’s range is contained within southern San Joaquin County and northern Stanislaus County, California. The only known populations of the species are located at Caswell Memorial State Park and the Oxbow Preserve, as well as in the South Delta and at the San Joaquin River National Wildlife Refuge.

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