Lepus alleni
antelope jackrabbit

Lepus alleni, the antelope jackrabbit, is found mostly along the western coast of Mexico, but also in southern Arizona in the United States. In Mexico, antelope jackrabbits inhabit the Mexican states adjacent to the Gulf of California and the Pacific Ocean: Sonora, Sinaloa, and northern Nayarit. In Arizona, antelope jackrabbits inhabit a small southern area, mostly in the Sonoran desert. Lepus alleni is also located on Tiburon, a small island off the coast of the Mexican state of Sonora. (Best and Henry, 1993)

In Arizona, antelope jackrabbits inhabit grassy slopes at moderate elevations. They are most commonly found in areas where grass grows well under desert shrubs that are moderately high and open. They are less common in creosote bush desert and in the low parts of valleys with dense mesquite stands. In Mexico, antelope jackrabbits prefers grasslands that are open and low, as well as foothills with patchy, low bushes and grass. They are most common in the foothills near the coast. (Best and Henry, 1993)

Size is the most distinctive trait of Lepus alleni; it is a large Lepus species, with the head and ears being especially large. Their ears are tall (on average 162mm long) and mostly devoid of hair except for fringes of white hair along the edges and on the tips. The side of the body (limbs, hips, rump) are white haired with black tips. The ventral surface (chin, throat, stomach, insides of limbs) are all white haired as well as the tail. The rest of the body (upper part) is yellow/brown with some black.

Lepus alleni deals with seasonality by adjusting its basal metabolic rate. It increases by 15% during the winter compared to the summer.

Antelope jackrabbits have many ways of dealing with heat. The fur is highly reflective and insulated, which helps to eliminate heat gain from the environment. Antelope jackrabbits can reduce blood flow to their large ears, which reduces heat exchanger. When not able to find shelter, Lepus alleni can tolerate heat stress at high levels better and for a longer time than Lepus californicus. (Best and Henry, 1993; David S. Hinds, 1977; Mearns, 1890; Vorhies and Taylor, 1933)

Not much is known about the lifespan of antelope jackrabbits as they are hard to keep alive in captivity and they are difficult to capture and study in the wild.

Lepus alleni is crepuscular and nocturnal, although they may be active during the day on cloudy days. Antelope jackrabbits spend their days in the hot season staying out of the sun in what are called "shelter forms." These are created by backing up under grass, weeds or brush, or just sitting in the shade of a cactus or mesquite trunk; though they preferentially choose mesquite and creosote bush. These forms help with the extreme heat during the day. Since leporids are coprophagic, forms might also help with the re-digestion of pellets, by making it safer to sit and digest. Like other jackrabbits, antelope jackrabbits are solitary. (Best and Henry, 1993; C.F. Brown, 2003; Vorhies and Taylor, 1933)

Home Range

Home ranges in Lepus alleni have not been documented.

Antelope jackrabbits uses their long ears to listen for predators and get a sense of their surroundings. Only in rare circumstances do antelope jackrabbits use sound as a form of communication. A pheromone may be used by this species in the form of a rectal gland that secretes a strong musky odor and may be used to scent mark a shelter form. (Vorhies and Taylor, 1933)

Lepus alleni is a folivore (leaf-eater), gramnivore (grass-eater) and succulent plant eater (esp. cacti). They do not actively drink water, but derive it from their diet, especially from eating cacti stems. May and June are the most arid months in their range and the rainy season occurs in July and August. In the dry season they depend mostly on mesquite leaves and cacti, but during the wet season, they switch to grass. Some minerals are derived from geophagy, but this behavior is rare. (Best and Henry, 1993; Vorhies and Taylor, 1933)

Lepus alleni is precocial at birth and ready to flee if a predator finds the mother and young soon after birth. Young are more nocturnal, less likely to leave a shelter, and generally more wary of their surroundings than are adults. Once grown, there are many predator avoidance strategies. One is to sit in a shelter form that is open on three sides, but offers protection from birds of prey. If a terrestrial predator is detected, the antelope jackrabbit can run or conceal itself in a shelter form. If it stays concealed, it will back into the shelter form, lay its ears close to the body, and extend the forelimbs for a quick escape. If it decides to run, it will take to all fours and flash a white area on its rump towards the predator. As it runs away in a zig-zag pattern, it will keep a white area exposed towards the predator, in hopes of confusing it. The antelope jackrabbit will also hop like a kangaroo in tall grasses to be able to see where the predator is. (Best and Henry, 1993; Vorhies and Taylor, 1933)

Through their grazing, antelope jackrabbits can force habitat succession in the direction of the climax stage on a range that is moderately deteriorated. On range that has more weeds than grasses (indicating worse deterioration), their grazing may further degrade the habitat. Antelope jackrabbits are important prey for medium to large terrestrial and avian predators. Their folivory influences the composition and health of their native habitats. (C.F. Brown, 2003; Vorhies and Taylor, 1933)

Through grazing, Lepus alleni is sometimes said to compete with domestic animals that graze on the same land. However, the impact may not be substantial as rabbits may graze in different ways and on different plants than domestic animals. In terms of quantity 15 antelope jackrabbits consume as much as 1 sheep, and 74 antelope jackrabbits consume as much as 1 domestic cow. (Best and Henry, 1993)

Antelope jackrabbits are valuable for food and their skin. (Best and Henry, 1993)

Lepus alleni habitat in southern Arizona is threatened by Lehmann lovegrass (Eragrostis lehmanniana), a non-native grass species which is not edible for antelope jackrabbits. Conversion of wild land for agriculture will lead to a further decline in antelope jackrabbit populations. Human impacts on antelope jackrabbit habitat also include housing developments, livestock grazing, recreational trails, and canal building. (Best and Henry, 1993; C.F. Brown, 2003)

The common name antelope jackrabbit is derived from the white flashing behavior of American pronghorns (Antilocapra americana) when they run. Antelope jackrabbits also flash their white tails when they flee.

Lepus alleni is named after John Asaph Allen who was the Curator of the Department of Mammals and Birds at the American Museum of Natural History.

Common names include: Allen's hare, Allen's jackrabbit, blanket jack, burro jack, jackass rabbit, Mexican jackrabbit, saddle jack, and wandering jackrabbit. (Best and Henry, 1993; Mearns, 1890)