San Diego Black-Tailed Jackrabbit (Lepus californicus bennettii)
San Diego Black-Tailed Jackrabbit (Lepus californicus bennettii)
General Distribution
Black-tailed jackrabbit (L. californicus), also known as black-tailed hare, occurs throughout the western
United States from central Washington in the north to Mexico in the south. This species has also been
introduced in New Jersey and Kentucky (Ingles 1965, Whitaker 1980).
San Diego (or coastal) black-tailed jackrabbit occurs only on the coastal side of the southern California
mountains where suitable jackrabbit habitat is less common (Stephenson and Calcarone 1999). This
subspecies has been recorded from northern Baja California through San Diego, Orange, Los Angeles,
and Ventura Counties, as well as on Mt. Pinos. Occurrences have been reported in Arroyo Seco,
Pasadena, San Felipe Valley, Jacumba, Santa Ysabel, and the Tijuana River (Hall 1981).
Bond (1977) provided locality information for a number of museum specimens collected in San Diego
County. Specimens were collected at elevations ranging from sea level to 6,000 feet (1,830
meters). Most San Diego County localities were west of National Forest System lands in southern
California, but specimens were reported from Santa Ysabel and the Laguna and Cuyamaca mountains
(USDA Forest Service file information).
The museum specimens representing mountain localities are of particular interest because they appear to
be outside of traditional habitat and represent areas where San Diego black-tailed jackrabbits are not
currently known to occur. In recent years, Steve Loe of the San Bernardino National Forest has
observed this species near the Del Rosa Fire Station at the base of the San Bernardino Mountains
(Stephenson and Calcarone 1999) and Vaughn (1954) reported this species near Cajon Pass. Systematics
Seventeen subspecies of L. californicus occur throughout western North America. San Diego black-tailed
jackrabbit and L. c. deserticola have distribution ranges in southern California (Hall 1981). Habitat Requirements
The black-tailed jackrabbit is a habitat generalist occurring in open areas or semi-open country, typically
in grasslands, agricultural fields or sparse coastal scrub (Bond 1977). Vaughan (1954) found San Diego
black-tailed jackrabbit in "thin stands" of coastal sage scrub and on the margins of citrus groves in the
lower foothills of the San Gabriel Mountains; however, it is generally not found in chaparral or
woodland habitats. Reproduction
Length of the breeding season depends on the duration and severity of winter. In California, black-tailed
jackrabbit can breed throughout the year. Ovulation is induced by copulation. Gestation lasts
approximately 40 days, and the average number of young per litter varies from year to year depending
on environmental conditions (Best 1996). A one-year-old female can produce 14 or more young per
year (Ingles 1965). Daily/Seasonal Activity
Black-tailed jackrabbit exhibits year-long diurnal and crepuscular activity patterns (Zeiner and others
1990). Mortality in black-tailed jackrabbit is divided equally between males and females. In Idaho, mortality in
black-tailed jackrabbit was 91 percent during the first year of life. Best (1996) estimated that black-tailed
jackrabbits live less than seven years in the wild. Diet and Foraging
Black-tailed jackrabbit is strictly herbivorous, feeding on a wide variety of grasses, forbs, and shrubs
(Zeiner and others 1990). Territoriality/Home Range
California black-tailed jackrabbits are probably not territorial (Tiemeier 1965). Home ranges of this
species in California averaged 45 acres (18.5 hectares) (Lechleitner 1958), with adults tending to have
larger home ranges than juveniles (Harestad and Bunnell 1979, Tiemeier 1965). Populations of black-tailed
jackrabbits appear to exhibit a 10-year cycle in density (Anderson and Shumar 1986). In Idaho,
density ranged from 0.04–0.61 individuals per acre (0.1–1.5 per hectare) (Smith and Nydegger 1985).
In Utah, densities have been calculated at 260 per square mile (100 per square kilometer) (Flinders and
Hansen 1973). Seton (1929) recorded densities of 84 individuals per acre (208 individuals per hectare)
near Bakersfield, California. Predator-Prey Relations
Predators include coyotes, hawks, owls, and foxes. The local abundance of many of these predators may
be related to the abundance of black-tailed jackrabbit (Best 1996). Literature Cited
Anderson, J.E.; Shumar, M.L. 1986. Impacts of black-tailed jackrabbits at peak population densities on
sagebrush steppe vegetation. Journal of Range Management 39.
Best, T.L. 1996. Lepus californicus. Mammalian Species. No. 530. American Society of Mammalogists.
Bond, S.I. 1977. An annotated list of the mammals of San Diego County, California. In: Transactions of
the San Diego Society of Natural History 18(14): 229–248.
Flinders, J.T.; Hansen, R.M. 1973. Abundance and dispersion of leporids within a shortgrass
ecosystem. Journal of Mammalogy 54: 287-291.
Hall, E.R. 1981. The mammals of North America. 2d ed. New York: John Wiley and Sons.
Harestad, A.S.; Bunnell, F.L. 1979. Home range and body weight – a reevaluation. Ecology 60: 389-402.
Ingles, Lloyd. 1965. Mammals of the Pacific states. Stanford, CA: Stanford Univ. Press.
Lechleitner, R.R. 1958. Movements, density, and mortality in a black-tailed jackrabbit
population. Journal of Wildlife Manage 22: 371-384.
Seton, E.T. 1929. Lives of game animals: An account of those land animals in America, north of the
Mexican border, which are considered "game," either because they have held the attention of sportsmen,
or received the protection of law. Garden City, NY: Doubleday, Doran & Company.
Smith, G.W.; Nydegger, N.C. 1985. A spotlight, line transect method for surveying jackrabbits. Journal
of Wildlife Management 49.
Stephenson, J.R.; Calcarone, G.M. 1999. Southern California mountains and foothills assessment:
Habitat and species conservation issues. General Technical Report GTR-PSW-175. Albany, CA: Pacific
Southwest Research Station, Forest Service, U.S. Department of Agriculture.
Tiemeier, O.W. 1965. Study area, reproduction, growth and development, age distribution, life span,
censusing, live trapping and tagging, crop damage, predation, and habits. In: The black-tailed
jackrabbit in Kansas. Kansas State University of Agriculture and Applied Science, Agricultural
Experiment Station, Technical Bulletin 140: 1-75.
Vaughn, T.A. 1954. Mammals of the San Gabriel mountains of California. University of Kansas
Publications, Museum of Natural History 7(9): 513-582.
Vorhies, C.T.; Taylor, W.B. 1933. The life histories and ecology of jackrabbits, Lepus alleni and Lepus
californicus ssp. in relation to grazing in Arizona. University of Arizona, College of Agriculture,
Agricultural Experimental Station, Technical Bulletin 49: 471-587.
Whitaker, J.O., Jr. 1980. National Audubon Society field guide to North American mammals. New
York: Alfred A. Knopf.
Zeiner, D.C.; Laudenslayer, W.F., Jr.; Meyer, K.E.; White, M., eds. 1990. California's wildlife. Volume
III: Mammals. California statewide wildlife habitat relationships system. Sacramento, CA: California
Department of Fish and Game.
Information gathered from California DFG - California Interagency Wildlife Task Group
