The antelope jackrabbit (''Lepus alleni'') is a species of North American

hare Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The g ...

found in southern Arizona and northwestern Mexico that occupies dry desert areas.

Behaviour

It is most active during twilight (

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of dayli ...

) and during the night (

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

), but can be active during the day when conditions are favorable (heavy cloud coverage).

Evolutionary history

Fossil evidence places the genus ''Lepus'' in North America approximately 2.5 million years ago. A now extinct jackrabbit species, ''Lepus giganteus'', was thought to exist in North America during this time. This species shared similar physical traits with the antelope jackrabbit, making it difficult to differentiate fossils of the two species. In a 2014 study, researchers hypothesized that ''L. giganteus'' served as a common ancestor to the antelope jackrabbit and

black-tailed jackrabbit The black-tailed jackrabbit (''Lepus californicus''), also known as the American desert hare, is a common hare of the western United States and Mexico, where it is found at elevations from sea level up to . Reaching a length around , and a ...

. The black-tailed jackrabbit coexists with the antelope jackrabbit and the two species maintain a

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species s ...

relationship. In the same 2014 study, genetic analysis concluded that three ''Lepus'' species share a common

white-sided jackrabbit The white-sided jackrabbit (''Lepus callotis''), also known as the Mexican hare, is a jackrabbit found in a limited range in North America, from southern New Mexico to northwestern and central Mexico. The animal is considered threatened in New M ...

ancestor: L. callotis (white-sided jackrabbit), L. alleni (antelope jackrabbit), and L. flavigularis (

Tehuantepec jackrabbit The Tehuantepec jackrabbit (''Lepus flavigularis'') is a jackrabbit endemic to Mexico. Description It is easily distinguished from other species by two black stripes that run from the base of the ears to the nape, and by its white flanks. Its un ...

). Based on this evidence, researchers also concluded that the

, though closely related to white-sided jackrabbits, exists in its own separate subclade.

Geographic range

In the United States, the antelope jackrabbit is found in parts of

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and states like

Chihuahua Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state **Chihuahua Mun ...

Nayarit Nayarit (), officially the Free and Sovereign State of Nayarit ( es, Estado Libre y Soberano de Nayarit), is one of the 31 states that, along with Mexico City, comprise the Federal Entities of Mexico. It is divided in 20 municipalities and its ...

Sinaloa Sinaloa (), officially the Estado Libre y Soberano de Sinaloa ( en, Free and Sovereign State of Sinaloa), is one of the 31 states which, along with Mexico City, comprise the Federal Entities of Mexico. It is divided into 18 municipalities and ...

and

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Federal Entities of Mexico. The state is divided into 72 municipalities; the ...

in Northwestern

Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...

. Compared to the other hare species present in North America, the antelope jackrabbit's range is limited. This species does not inhabit areas further east than the

sky island Sky islands are isolated mountains surrounded by radically different lowland environments. The term originally referred to those found on the Mexican Plateau, and has extended to similarly isolated high-elevation forests. The isolation has s ...

s in Arizona and the

Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...

in Mexico. It also does not radiate west of

Florence, Arizona , settlement_type = Town , image_skyline = Main Street original town-site of Florence Arizona National Register of Historic Places.jpg , imagesize = , image_caption = Main Street of the original town ...

. As of July 2017 it had been spotted and photographed by a National Park Ranger in the Lake Mead Recreational Area in Nevada.

Habitat

The antelope jackrabbit is found in a variety of tropic and subtropic habitats. It can be found in grassy hills or plains, preferring habitats with large, desert shrubs above long grass. This species can also be found in more barren desert habitats. A 2014 study focusing on ecology indicated that the ideal habitat for an antelope jackrabbit includes grassy ground cover and a mesquite overstory. This species does not prefer an arid climate; instead, antelope jackrabbits live in areas with summer precipitation amounts ranging from 90 mm to 360 mm. Unlike the black-tailed jackrabbit which survives in less humid conditions, the antelope jackrabbit inhabits locations with higher humidity.

Description

The antelope jackrabbit is a large ''Lepus'' species. Male and female antelope jackrabbits are identical in appearance. This species is large in size with long, pointed ears and a distinct coat coloration. The antelope jackrabbit has a white belly, light grey sides, a back peppered with black, and orange coloration on the neck and chest. It is similar to species like the

and

. Its body length ranges from 52 to 58 cm (22 in) long and its tail can be 5 to 10 cm (3 in) long. Its front legs grow to be 10 to 20 cm (3.9 to 7.9 in) and the back legs can grow to be 20 to 30 cm (7.9 to 11.8 in) long. The antelope jackrabbit's ears grow to be 14–17 cm (6 in) and it can weigh up to . The species has a very large skull and a long rostrum. Its ears are extremely long with white on the point and edges. The bi-colored tail is black on top and a pale grey below. The antelope jackrabbit has light grey sides, an orange neck and chest, and a back speckled with black.

Feeding

The antelope jackrabbit feeds on cacti, grasses, and other leafy vegetation. This species has been observed digging and eating soil in an attempt to intake minerals and other nutrients. They can be classified as

folivore In zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and often toxic compounds.Jones, S., Martin, R., & Pilbeam, D. (1 ...

s and graminivores. It feeds on cacti, mesquite leaves, and other vegetation.

Reproduction

Antelope jackrabbits breed from December to September and the gestation period is roughly six weeks long. Females have up to four litters per year ranging from one to five individuals. A baby hare, called a leveret, is born

precocial In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...

; its eyes are open, it is active, and covered with fur. Young are born in shallow dirt nests that are formed by scraping the surface of the ground.

Threats

Known predators of the antelope jackrabbit include

bobcat The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the ...

coyote The coyote (''Canis latrans'') is a species of canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecological nich ...

s, and

golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...

s. Since antelope jackrabbits attract predators that are also a threat to livestock, they are hunted by humans to reduce potential problems. This species is also hunted for human consumption or for their valuable pelt. Habitat loss also poses a threat to antelope jackrabbits because

agricultural expansion Agricultural expansion describes the growth of agricultural land (arable land, pastures, etc.) especially in the 20th and 21st centuries. The agricultural expansion is often explained as a direct consequence of the global increase in food and en ...

is interfering with their habitats. Grazing livestock reduce the abundance of grasses and herbaceous plants in areas where antelope jackrabbits reside.

Subspecies

There are three recognized subspecies: *''L a. i alleni'' *''L. a. palitans'' *''L. a. tiburonensis''

References

External links

University of Michigan: ''Lepus alleni''
{{Taxonbar, from=Q577630 Lepus Mammals of Mexico Mammals of the United States Fauna of the Sonoran Desert Fauna of the Southwestern United States Natural history of Arizona Natural history of Sonora Mammals described in 1890