Lepus californicus (Black-tailed Jackrabbit) 

Written by Mark Lange (Mammalogy Lab--Fall 2003)

Edited by Karah Gallagher and Jennifer Bailey

Map prepared by Greg T. Lewellen

Lepus californicus has a very broad distribution in the United States and in Mexico.  In the United States Lepus californicus ranges from as far north as Washington state and stretches south to cover most of Texas (Best 1996).  Lepus californicus range spreads as far west as the pacific coast and as far east as Arkansas, Missouri, and Iowa (Lechleitner 1958).  Lepus californicus is found in all areas of New Mexico, California, Nevada, Arizona, Oklahoma, Kansas, and Missouri (Whitaker 2000).  Lepus californicus also inhabits all of northern Mexico and goes as far south into Mexico as Hidalgo (Best 1996).  Lepus californicus thrives in hot, arid, grassy, and brushy country (Hoffmeister 1971).  Lepus californicus inhabits most of Texas except for the far east region near the border with Louisiana (Best 1996). 

Photo courtesy Texas Parks & Wildlife © 2003

Physical Characteristics:

Lepus californicus has many distinct features but yet is often confused with the white-tailed jackrabbit (Lepus townsendii), which lacks black on the tail, and the white-sided jackrabbit (Lepus callotis).  Lepus californicus is a mid-sized mammal (Reese and Haines 1978).  Lepus californicus is very identifiable by its long, naked ears (Hoffmeister 1971).  The ears and tail of Lepus californicus are tipped with black.  The body consists of relatively dense brownish-gray hair with white hair occurring on the ventral side of the abdomen as well as under the tail (Griffing 1974).  Although there is a difference in the range of body mass, all other measurements between males and females are similar.  The ranges are as follows:  body mass (males), 2070-2800g; body mass (females), 2320-3410g; hind foot, 123-143mm; ear, 108-135mm; tail, 61-81mm (Goodwin and Currie 1965).  Lepus californicus is a sexually dimorphic species but the obvious differences are mostly internal rather than external (Lechleitner 1959).  Lepus californicus has longer back legs than front legs.  The skull consists of a large diastema that leads to four upper incisors and two lower incisors.  The skull is moderately shallow with a prolonged braincase (Best 1996).

Natural History:

Food Habits: Due to the fact that Lepus californicus thrives in very dry and arid habitats it is adapted to eat a variety of plants.  Lepus californicus often prefers many types of grasses and woody plants (Flinders and Hansen 1975).  In areas consisting of primarily sage type plants the most common species of sage consumed by Lepus californicus is saltsage.  Lepus californicus prefers the saltsage to other species of sage such as whitesage.  At the same time Lepus californicus prefers this sage species to grasses that are not in their growth stages (Currie and Goodwin 1966).  Lepus californicus is prone to eat grasses only when they are green and growing, at other times they consume shrubs and sages (Flinders and Crawford 1977).  In agricultural based areas with large plots of planted crops Lepus californicus consumes large amount of wheat and some broad leaf plants such as maize.  When feeding Lepus californicus was observed to consume plants from the leaf tip and eat downward (Currie and Goodwin 1966).

Reproduction: The breeding ritual of Lepus californicus is one that consists of many unusual and intense activities.  Males have been observed circling females and even chasing them at high speeds over long distances (Blackburn 1973).  The ratio of males to females of Lepus californicus is very close to equal (Bronson and Tiemeier 1958).  After the initial mating ritual occurs, copulation usually takes place.  After the initial copulation, the male usually jumps backward and squeals.  Copulation can occur up to four times after the initial copulation (Blackburn 1973).  The male penis is completely enclosed in the body cavity.  The female has an unusually large corpora lutea (Lechleitner 1959).  The females often have three to four litters per year with each litter containing two to four individuals (Bronson and Tiemeier 1958).  The gestation length for Lepus californicus is on average 43 days but can range from 41 to 47 days.  The young are born fully haired and nurse only ten days before converting to solid food.  Lepus californicus have mature ear and hind foot length at 15 weeks, mature weight at 32 weeks, and mature total length at 28 weeks (Haskell and Reynolds 1947).

Behavior: Lepus californicus is a nocturnal species but not many studies have been done on the behavior of them at night (Costa et al. 1976).  The daily home range of Lepus californicus consists on average of about 60 acres and a seasonal home range on average of 270 acres (Nelson and Wagner 1973).  Lepus californicus become active about 30 minutes before sundown and spend three to four hours of the night primarily feeding.  Lepus californicus have been observed lying on their sides in the morning sun to collect warmth.  During hot summer days they adjust to the heat by panting and sometimes digging shallow burrows.  Lepus californicus activity dramatically declines during the winter months (Costa et al. 1976).  Another interesting behavior of Lepus californicus includes that the species has a dramatic fear of water.  When cornered with an easy escape route through shallow water individuals pace back and forth and hunch up but never come in contact with water (Hawbecker 1942).

Habitat:  Lepus californicus is found in dry and very arid environments.  They thrive on shrubs, sages, and grasses and are adapted for the heat.  The oversized ears are used to lose heat and are larger in rabbits in hotter climates (Dice and Blossom 1937).  Lepus californicus excludes itself to desert-like areas with relatively small vegetation.  Lepus californicus also avoids elevations that exceed 7000ft (Long 1940).

Lepus californicus is often known as a pest species.  The main complaint of damage from the species is that it often competes against livestock for available food.  Lepus californicus has been known to eat massive amounts of food intended for livestock (Mapston 1988).

Conservation Status:

Lepus californicus is a very abundant species and is in no danger of becoming endangered.  It is very widespread with massive numbers nationwide.  Lepus californicus is a common prey item of coyotes (Canis latrans), but because of quick reproduction, the species is able to keep a comfortable abundance level in the United States (French et al. 1965).

References:

Best, T.L.  1996.  Lepus californicus.  Mammalian Species 530:1-10.

Blackburn, D.F. 1973.  Courtship behavior among white-tailed and black-tailed jackrabbits.  The Great Basin Naturalist 33:203-204.

Bronson, F.H., and O.W. Tiemeier.  1958.  Reproduction and age distribution of black-tailed jackrabbits in Kansas.  The Journal of Wildlife Management 22:409-414.

Costa, W.R., K.A. Nagy, and V.H. Shoemaker.  1976.  Observation of the behavior of jackrabbits (Lepus californicus) in the Mojave Desert.  Journal of Mammalogy 57:399-402.

Currie, P.O., and D.L. Goodwin.  1966.  Consumption of forage by black-tailed jackrabbits and salt-desert ranges in Utah.  The Journal of Wildlife Management 30:304-311.

Dice, L.R., and P.M. Blossom. 1937.  Studies of mammalian ecology in southwestern North America with special attention to the colors of desert mammals.  University of Michigan 40-42.

Flinders, J.T., and J.A. Crawford.  1977.  Composition and degradation of jackrabbit and cottontail fecal pellets, Texas High Plains.  Journal of Range Management 30:217-220.

Flinders, J.T., and R.M. Hansen.  1975.  Spring population responses of cottontails and jackrabbits to cattle grazing short-grass prairie.  Journal of Range Management 28:290-293.

French, N.R., R. McBride, and J. Detmer.  1965.  Fertility and population density of the black-tailed jackrabbit.  The Journal of Wildlife Management 29:14-26.

Goodwin, D.L., and P.O. Currie.  1965.  Growth and development of black-tailed jack rabbits.  Journal of Mammalogy 46:96-98.

Griffing, J.P.  1974.  Body measurements of black-tailed jackrabbits of southeastern New Mexico with implications of Allen’s rule.  Journal of Mammalogy 55:674-678.

Haskell, H.S., and H.G. Reynolds.  1947.  Growth, developmental food requirements, and breeding activity of the California jack rabbit.  Journal of Mammalogy 28:129-136.

Hawbecker, A.C.  1942.  Dislike of water by the California jack rabbit.  Journal of Mammalogy 23:98-99.

Hoffmeister, D.F.  1971.  Mammals of the Grand Canyon.  University of Illinois Press,Chicago 91-92.

Lechleitner, R.R. 1958.  Movements, density, and mortality in a black-tailed jackrabbit population.  The Journal of Wildlife Management 22:371-384.

Lechleitner, R.R.  1959.  Sex ratio, age classes and reproduction of the black-tailed jack rabbit.  Journal of Mammalogy 40:63-81.

Long, W.S.  1940.  Notes on the life histories of some Utah mammals.  Journal of Mammalogy 21:170-180.

Mapston, M.  1988.  Controlling cottontail and jackrabbit damage.  Animal Damage Control L:1910-1911.

Nelson, L., Jr., and F.H. Wagner.  1973.  Effects of sublethal, cerebral X-irradiation on movement, activity and home-range patterns of black-tailed jackrabbits.  Health Physics 25:507-514.

Reese, J.B., and H. Haines.  1978.  Effects of dehydration on metabolic rate and fluid distribution in the jackrabbit, Lepus californicus.  Physiological Zoology 51:155-165.

Whitaker, J.O.  2000.  Lepus californicus.  National Audubon Society Field Guide to North American Mammals.  Alfred A. Knopf, New York.