White-sided Jackrabbit - Behavior

Behavior

Most activity of the white-sided jackrabbit occurs during the night 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 the white-sided jackrabbit 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.

The white-sided jackrabbit constructs and utilizes shelter forms averaging 15 in (38 cm) in length, 20 in (51 cm) in width, and 7–8 in (18–20 cm) 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. The white-sided jackrabbit 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.

The white-sided jackrabbit 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 the white-sided jackrabbit, however, it is not known which member of the pair makes this sound.