Black-tailed jackrabbit

Appearance

Like other jackrabbits, the blacktail has distinctive long ears, and the long, powerful rear legs characteristic of hares. Reaching a length of about 2 feet , and a weight from 3 to 6 pounds , the black-tailed jackrabbit is the third largest North American hare, after the antelope jackrabbit and the white-tailed jackrabbit. The black-tailed jackrabbit's dorsal fur is agouti , and its undersides and the insides of its legs are creamy white. The ears are black-tipped on the outer surface, and unpigmented inside. The ventral surface of the tail is grey to white, and the black dorsal surface of the tail continues up the spine for a few inches to form a short, black stripe. The females are larger than males, with no other significant differences.

Distribution

Although seventeen subspecies are recognized, this number may be excessive. Using cluster analysis of anatomical characters, Dixon and others found that black-tailed jackrabbit subspecies separated into two distinct groups that are geographically separated west and east of the Colorado Rocky Mountains and the Colorado River. They suggested only two infrataxa are warranted: the western subspecies ''L. c. californicus'' and the eastern subspecies ''L. c. texianus''.

Black-tailed jackrabbit is the most widely distributed jackrabbit in North America. Native black-tailed jackrabbit populations occur from central Washington east to Missouri and south to Baja California Sur and Zacatecas. Black-tailed jackrabbit distribution is currently expanding eastward in the Great Plains at the expense of white-tailed jackrabbit. Black-tailed jackrabbit has been successfully introduced in southern Florida and along the coastline in Maryland, New Jersey, and Virginia.

Distribution of subspecies occurring entirely or partially in the United
States is as follows:

⤷ ''Lepus californicus altamirae''
⤷ ''L. c. asellus''
⤷ ''L. c. bennettii'' – coastal southern California to Baja California Norte
⤷ ''L. c. californicus'' – coastal Oregon to coastal and Central Valley California
⤷ ''L. c. curti''
⤷ ''L. c. deserticola'' – southern Idaho to Sonora
⤷ ''L. c. ememicus'' – central Arizona to Sonora
⤷ ''L. c. festinus''
⤷ ''L. c. magdalenae''
⤷ ''L. c. martirensis''
⤷ ''L. c. melanotis'' – South Dakota to Iowa, Missouri, and central Texas
⤷ ''L. c. merriamai'' – south-central and southeastern Texas to Tamaulipas
⤷ ''L. c. richardsonii'' – central California
⤷ ''L. c. sheldoni''
⤷ ''L. c. texianus'' – southeastern Utah and southwestern Colorado to Zacatecas
⤷ ''L. c. wallawalla'' – eastern Washington to northeastern California and northwestern Nevada
⤷ ''L. c. xanti''

Habitat

The black-tailed jackrabbit can occupy a wide range of habitats as long as there is diversity in plant species. It requires mixed grasses, forbs, and shrubs for food, and shrubs or small trees for cover. It prefers moderately open areas without dense understory growth and is seldom found in closed-canopy habitats. For example, in California, black-tailed jackrabbit is plentiful in open chamise chaparral interspersed with grasses, but does not occupy closed-canopy chaparral. Similarly, black-tailed jackrabbit occupies clearcuts and early seral coniferous forest, but not closed-canopy coniferous forest.

Black-tailed jackrabbit does not migrate or hibernate during winter; the same habitat is used year-round. There is diurnal movement of 2 to 10 miles from shrub cover in day to open foraging areas at night. Home range area varies with habitat and habitat quality. Home ranges of 0.4 to 1.2 square miles have been reported in big sagebrush and black greasewood communities of northern Utah.



Black-tailed jackrabbit require shrubs or small conifers for hiding, nesting, and thermal cover, and grassy areas for night feeding. A shrub-grassland mosaic or widely spaced shrubs interspersed with herbs provides hiding cover while providing feeding opportunities. Small shrubs do not provide adequate cover. In the Snake River Birds of Prey Study Area in southwestern Idaho, black-tailed jackrabbit was more frequent on sites dominated by big sagebrush or black greasewood than on sites dominated by the smaller shrubs winterfat or shadscale . Black-tailed jackrabbit does not habitually use a burrow, although it has occasionally been observed using abandoned burrows for escape and thermal cover.

Food

The black-tailed jackrabbit diet is composed of shrubs, small trees, grasses, and forbs. Throughout the course of a year, black-tailed jackrabbit feed on most if not all of the important plant species in a community. Growth stage and moisture content of plants may influence selection more than species. Shrubs generally comprise the bulk of fall and winter diets, while grasses and forbs are used in spring and early summer. This pattern varies with climate: herbaceous plants are grazed during greenup periods while the plants are in prereproductive to early reproductive stages, and shrubs are utilized more in dry seasons. Shrubs are browsed throughout the year, however. Most of a jackrabbit's body water is replaced by foraging water-rich vegetation. Jackrabbit require a plant's water weight to be at least five times its dry weight in order to meet daily water intake requirements. Therefore, black-tailed jackrabbits switch to phreatophyte shrubs when herbaceous vegetation is recovering from their foraging.

Plant species used by black-tailed jackrabbit are well documented for desert regions. Forage use in other regions is less well known. However, black-tailed jackrabbit browse Douglas fir , ponderosa pine ,
lodgepole pine , and western hemlock seedlings, and oak seedlings and sprouts.

Predators

Black-tailed jackrabbit is an important prey species for many raptors and carnivorous mammals. The black-tailed jackrabbit and Townsend's ground squirrel are the two most important prey species on the Snake River Birds of Prey Study Area. Hawks preying on black-tailed jackrabbit include the ferruginous hawk , white-tailed hawk , Swainson's hawk , and red-tailed hawk . The black-tailed jackrabbit is the primary prey of Swainson's, red-tailed, and ferruginous hawks on Idaho and Utah sites. Other raptors consuming black-tailed jackrabbit include the great horned owl , burrowing owl , golden eagle , bald eagle , and Eurasian eagle-owl . There is a significant correlation between golden eagle production and black-tailed jackrabbit productivity. In Colorado and southeastern Wyoming, black-tailed jackrabbit constitute 9% of nesting bald eagles' diet. Jackrabbits and cottontails combined form 9% of the diet of bald eagles wintering on National Forests in Arizona and New Mexico.

Mammalian predators include coyote , bobcat , lynx , domestic dog , domestic cat , red fox , common gray fox , American badger , wolf , and mountain lion . In many areas, black-tailed jackrabbit is the primary item in coyote diets. It is locally and regionally important to other mammalian predators. One study found that jackrabbits made up 45% of the bobcat diet in Utah and Nevada. Another Utah–Nevada study found that jackrabbits were the fourth most commonly consumed prey of mountain lion.

Rattlesnakes and garter snakes prey on black-tailed jackrabbit young. Raccoons and striped skunks may also capture young.