Lepus callotis
Encyclopedia
The White-sided Jackrabbit (Lepus callotis) also known as the mexican hare is a jackrabbit found in a limited location in North America
. Its range only extends from southern New Mexico
to northwestern and central Mexico
. The animal is actually considered threatened in New Mexico with its numbers in decline in recent years.
s at high elevations, including the grassy plain
s of southwestern New Mexico and the open plains of the southern Mexican tableland. It avoids areas that are full of hills or mountains. It prefers level lands full of grass
es and also will avoid areas with that are full of tree
s and shrub
s.
is present in this species; females are generally larger than the males.
The dorsal pelage of the White-sided Jackrabbit is short and coarse. The color is pale cinnamon color heavily mixed with black. The underparts are white with traces of colored patches in front of the thighs. The tail has black hairs tipped with white on the upper surface and is all white on the underside. The sides are distinguishable from other species in that they are pure white, this is where they obtained their name. The rump and thighs are also white and lined with a few black hairs. A median black line concealed by sooty, brownish, and white-tipped hairs divides the rump. The limbs are white, but their outer surface is stained a buffy color. The gular pouch is also buffy while the sides of the neck and shoulders become more ochraceous in color. The head is a cream buff color, mixed with black, with whitish areas around the sides of the eyes. The ears are covered with short yellowish-brown hairs that are mixed with black anteriorly and white posteriorly. The apex of the ear is white-tipped. Below the apex of the ear is a tuft of black hair. The long fringes on the anterior edge of the ear are ochraceous buff while the fringes of the tip of the ear and posterior edge are white. The inner surface of the ear is almost bare except for a dusky spot on the posterior border. The nape is ochraceous buff in color.
The winter pelage of the White-sided Jackrabbit is iron gray on the rump, back, and outside of the hind legs. The front of the hind legs and the tops of the feet are white. The front of the fore legs and top of the forefeet range from a pale gray to a dull iron-gray. The median black line of the rump is not strongly distinguishable and does not extend much further than the base of the tail. The top, sides, and tip of the tail are black while the underside is two-thirds white and one-third black. The top and sides of the head and back are dark-pinkish buff overlaid with black. The nape is usually black. The ears are dark bluff, black, and white. The front border of the ears are fringed with buff or ochraceous buff hairs, and the posterior border and tip are white. The underside of the neck is dark grayish bluff and the remaining underparts, including the flanks, are white.
is around 2. The young tend to have a soft, woolly coat
in early life and attain sexual maturity
at a rapid rate. Breeding in Lepus callotis does not begin within the first calendar year following its birth.
or at dusk
, particularly on clear nights with bright moonlight. Its activity may be limited by cloud cover, precipitation
, and wind, but temperature
has little effect. The escape behavior consists of alternately flashing its white sides when running away. The White-sided Jackrabbit, when escaping, makes rather long, high leaps. When startled by or alarmed by a predator, it leaps straight upwards while extending the hind legs and flashing the white sides. In its resting position, a White-sided Jackrabbit is camouflaged with its surroundings. The long hind legs and feet are adapted for speed, giving the animal lift and an ability to run in a zig-zag fashion that surpasses its pursuers. The long ears serve to locate sound as well as regulate temperature when they are raised like a fan to catch passing breezes in hot conditions. The eyes, like those of most nocturnal animals or animals that are active at dusk, are laterally arranged, giving them a complete field of vision (360 degrees). As a result, approaching danger can be perceived in advance.
A conspicuous trait of L. callotis is its tendency to occur in pairs, usually one male and one female. It exhibits a pair bond that is most evident during the breeding season. After establishment of the pair bond, the male defends the pair from other intruding males. The purpose of such pair bonds may be to keep the sexes together in areas of low density. The members of the pair are usually within 15-20 feet of each other and run together when approached by intruders. The pair bond may not be broken during pregnancy
.
L. callotis constructs and utilizes shelter forms averaging 15 inches in length, 20 inches in width, and 7-8 inches in depth. The shelter form is usually located in clumps of grass and surrounded by dense stands of tobosa grass. The White-sided Jackrabbit may also occupy underground shelters, but this behavior is rare. L. callotis forages by chewing and pulling grass blades near the ground until they are either uprooted or broken off. The food is ingested by chewing the grass that is sticking out of the mouth, with the head raised and the body sitting in a crouched position. The forepaws are not used in feeding except to brace against the ground as the grass is bitten off or uprooted. When eating certain nutgrass, however, the forepaws are used to excavate the bulbous tubers, leaving behind oval foraging depressions in which fecal pellets are often deposited.
L. callotis has three types of vocalizations
. The alarm or fear reaction consists of a high-pitched scream. Another sound, emitted by males in a pair when approached by an outside intruding male, is a series of harsh grunts until the intruder leaves or is chased away. A third vocalization, consisting of a trilling grunt is heard during the sexual chase of L. callotis, however, it is not known which member of the pair makes this sound.
, wolftail, blue grama
, vine mesquite, ring muhly, wooly Indian wheat, and Wright buckwheat. The significant non-grass item found in their diets was sedge nutgrass.
Many species of rabbit and hare are also sought after their meat and fur. This is also untrue of the White-sided Jackrabbit and it is protected in most of its habitat region.
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. Its range only extends from southern New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
to northwestern and central Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The animal is actually considered threatened in New Mexico with its numbers in decline in recent years.
Habitat
The White-sided Jackrabbit inhabits plateauPlateau
In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...
s at high elevations, including the grassy plain
Plain
In geography, a plain is land with relatively low relief, that is flat or gently rolling. Prairies and steppes are types of plains, and the archetype for a plain is often thought of as a grassland, but plains in their natural state may also be covered in shrublands, woodland and forest, or...
s of southwestern New Mexico and the open plains of the southern Mexican tableland. It avoids areas that are full of hills or mountains. It prefers level lands full of grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
es and also will avoid areas with that are full of tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s and shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s.
Description
The White-sided Jackrabbit has a body length that ranges from 16 to 30 inches long. Its tail will grow to lengths of 1 to 4 inches long. Its legs grow from 4 to 6 inches in the front and the back legs can grow from 6 12 inches long. The White-sided Jackrabbit's ears grow an astounding 2 to 6 inches when fully grown. The forepaws have five toes while the back paws have four. All toes end in sturdy claws. Some sexual dimorphismSexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
is present in this species; females are generally larger than the males.
The dorsal pelage of the White-sided Jackrabbit is short and coarse. The color is pale cinnamon color heavily mixed with black. The underparts are white with traces of colored patches in front of the thighs. The tail has black hairs tipped with white on the upper surface and is all white on the underside. The sides are distinguishable from other species in that they are pure white, this is where they obtained their name. The rump and thighs are also white and lined with a few black hairs. A median black line concealed by sooty, brownish, and white-tipped hairs divides the rump. The limbs are white, but their outer surface is stained a buffy color. The gular pouch is also buffy while the sides of the neck and shoulders become more ochraceous in color. The head is a cream buff color, mixed with black, with whitish areas around the sides of the eyes. The ears are covered with short yellowish-brown hairs that are mixed with black anteriorly and white posteriorly. The apex of the ear is white-tipped. Below the apex of the ear is a tuft of black hair. The long fringes on the anterior edge of the ear are ochraceous buff while the fringes of the tip of the ear and posterior edge are white. The inner surface of the ear is almost bare except for a dusky spot on the posterior border. The nape is ochraceous buff in color.
The winter pelage of the White-sided Jackrabbit is iron gray on the rump, back, and outside of the hind legs. The front of the hind legs and the tops of the feet are white. The front of the fore legs and top of the forefeet range from a pale gray to a dull iron-gray. The median black line of the rump is not strongly distinguishable and does not extend much further than the base of the tail. The top, sides, and tip of the tail are black while the underside is two-thirds white and one-third black. The top and sides of the head and back are dark-pinkish buff overlaid with black. The nape is usually black. The ears are dark bluff, black, and white. The front border of the ears are fringed with buff or ochraceous buff hairs, and the posterior border and tip are white. The underside of the neck is dark grayish bluff and the remaining underparts, including the flanks, are white.
Reproduction
The breeding season of the White-sided Jackrabbit is a minimum of 18 weeks, occurring from mid-April to mid-August. The average number of young per litterLitter (animal)
A litter is the offspring at one birth of animals from the same mother and usually from one set of parents. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from...
is around 2. The young tend to have a soft, woolly coat
Coat (animal)
Coat, or the nature and quality of a show mammal's pelage, is important to the animal fancy in the judging of the animal, particularly at conformation dog shows, cat shows and horse shows...
in early life and attain sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
at a rapid rate. Breeding in Lepus callotis does not begin within the first calendar year following its birth.
Behavior
Most activity of the White-sided Jackrabbit occurs during the nightNight
Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day...
or at dusk
Dusk
Dusk is the beginning of darkness in the evening, and occurs after twilight, when the sky generally remains bright and blue. Civil dusk is when the earth has rotated enough that the center of the sun is at 6° below the local horizon...
, particularly on clear nights with bright moonlight. Its activity may be limited by cloud cover, precipitation
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...
, and wind, but temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
has little effect. The escape behavior consists of alternately flashing its white sides when running away. The White-sided Jackrabbit, when escaping, makes rather long, high leaps. When startled by or alarmed by a predator, it leaps straight upwards while extending the hind legs and flashing the white sides. In its resting position, a White-sided Jackrabbit is camouflaged with its surroundings. The long hind legs and feet are adapted for speed, giving the animal lift and an ability to run in a zig-zag fashion that surpasses its pursuers. The long ears serve to locate sound as well as regulate temperature when they are raised like a fan to catch passing breezes in hot conditions. The eyes, like those of most nocturnal animals or animals that are active at dusk, are laterally arranged, giving them a complete field of vision (360 degrees). As a result, approaching danger can be perceived in advance.
A conspicuous trait of L. callotis is its tendency to occur in pairs, usually one male and one female. It exhibits a pair bond that is most evident during the breeding season. After establishment of the pair bond, the male defends the pair from other intruding males. The purpose of such pair bonds may be to keep the sexes together in areas of low density. The members of the pair are usually within 15-20 feet of each other and run together when approached by intruders. The pair bond may not be broken during pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
.
L. callotis constructs and utilizes shelter forms averaging 15 inches in length, 20 inches in width, and 7-8 inches in depth. The shelter form is usually located in clumps of grass and surrounded by dense stands of tobosa grass. The White-sided Jackrabbit may also occupy underground shelters, but this behavior is rare. L. callotis forages by chewing and pulling grass blades near the ground until they are either uprooted or broken off. The food is ingested by chewing the grass that is sticking out of the mouth, with the head raised and the body sitting in a crouched position. The forepaws are not used in feeding except to brace against the ground as the grass is bitten off or uprooted. When eating certain nutgrass, however, the forepaws are used to excavate the bulbous tubers, leaving behind oval foraging depressions in which fecal pellets are often deposited.
L. callotis has three types of vocalizations
Animal communication
Animal communication is any behavior on the part of one animal that has an effect on the current or future behaviour of another animal. The study of animal communication, is sometimes called Zoosemiotics has played an important part in the...
. The alarm or fear reaction consists of a high-pitched scream. Another sound, emitted by males in a pair when approached by an outside intruding male, is a series of harsh grunts until the intruder leaves or is chased away. A third vocalization, consisting of a trilling grunt is heard during the sexual chase of L. callotis, however, it is not known which member of the pair makes this sound.
Food
The diet of the White-sided Jackrabbit consists primarily of grasses including buffalograss, tobosagrass, fiddleneckFiddleneck
A fiddleneck is a flowering plant in the genus Amsinckia. The name derives from the flower stems, bearing many small flowers, which curl over at the top in a manner reminiscent of the head of a fiddle...
, wolftail, blue grama
Blue grama
Blue Grama, Bouteloua gracilis, is a long-lived, warm season, C4 perennial grass native to North America. It is most commonly found from Alberta east to Manitoba and south across the Rocky Mountains, Great Plains, and Midwest states to Mexico...
, vine mesquite, ring muhly, wooly Indian wheat, and Wright buckwheat. The significant non-grass item found in their diets was sedge nutgrass.
Human interaction and impact
Although many species of jackrabbit and hare are considered pests because they damage crops, fields, and orchards, the White-sided Jackrabbit is usually not considered a pest and has no known adverse conditions on human property.Many species of rabbit and hare are also sought after their meat and fur. This is also untrue of the White-sided Jackrabbit and it is protected in most of its habitat region.
Conservation efforts
The White-sided Jackrabbit is considered endangered throughout its range in Mexico and southwestern New Mexico. L. callotis commonly comes into contact with agriculture. As a result, the overgrazing of domestic livestock may be one of the factors contributing to its decline and the apparent replacement by Lepus californicus, which has been highly adaptable to these habitat changes. Prospects for the survival of the White-sided Jackrabbit in many parts of its range are considered poor at best.Subspecies
There are two subspecies of this jackrabbit:- Lepus callotis callotis
- Lepus callotis gaillardi