Lepus callotis Wagler, 1830

Taxonomic Naming

The white-sided jackrabbit, scientifically known as Lepus callotis Wagler, 1830, has an adult body length ranging from 16 to 30 inches (41 to 76 cm).

Body and Tail Length

Its tail reaches 1 to 4 inches (2.5 to 10.2 cm) in length. Front legs grow 4 to 6 inches (10 to 15 cm) long, while back legs reach 6 to 12 inches (15 to 30 cm) in length.

Ear and Paw Morphology

Fully grown ears measure 2 to 6 inches (5.1 to 15.2 cm). This species has five toes on its fore paws and four toes on its back paws, and all toes end in sturdy claws.

Sexual Dimorphism

Sexual dimorphism occurs in white-sided jackrabbits, with females generally larger than males.

Dorsal and Ventral Fur Coloration

The dorsal fur of the white-sided jackrabbit is short and coarse, colored pale cinnamon heavily mixed with black. Underparts are white, with faint colored patches on the front of the thighs.

Tail Markings

The upper surface of the tail has black hairs tipped with white, and the entire underside of the tail is white. The species is named for its distinctive pure white sides, a feature that sets it apart from related species.

Rump and Thigh Markings

The rump and thighs are also white, lined with a small number of black hairs. A median black line divides the rump, and this line is concealed by sooty, brownish, and white-tipped hairs.

Limb and Neck Coloration

The limbs are white, but their outer surfaces are stained buff. The gular pouch is also buffy, while the sides of the neck and shoulders take on a more ochraceous color.

Head Coloration

The head is cream buff mixed with black, with whitish areas around the sides of the eyes.

Ear External Markings

Ears are covered in short yellowish-brown hairs that are mixed with black on the anterior section and white on the posterior section. The ear apex is white-tipped, with a tuft of black hair just below the apex.

Ear Fringe and Inner Surface

The long fringes on the anterior edge of the ear are ochraceous buff, while fringes on the ear tip and posterior edge are white. The inner surface of the ear is almost entirely bare, with only a dusky spot on the posterior border.

Summer Nape Color

The nape is ochraceous buff.

Winter Pelage Trunk and Legs

The winter pelage of the white-sided jackrabbit differs from the summer coat: the rump, back, and outside of the hind legs are iron gray. The front of the hind legs and the tops of the feet are white.

Winter Foreleg and Rump Markings

The front of the fore legs and top of the fore feet range from pale gray to dull iron-gray. The median black line on the rump is not clearly distinguishable and does not extend much beyond the base of the tail.

Winter Tail Coloration

The top, sides, and tip of the tail are black, while the underside is two-thirds white and one-third black.

Winter Head and Nape Color

The top and sides of the head and back are dark-pinkish buff overlaid with black. The nape is usually black.

Winter Ear Markings

Ears are dark buff, black, and white. The front border of the ears is fringed with buff or ochraceous buff hairs, while the posterior border and tip are white.

Winter Underpart Coloration

The underside of the neck is dark grayish buff, and all other underparts including the flanks are white.

Habitat Range and Preference

The white-sided jackrabbit inhabits high-elevation plateaus, including the grassy plains of southwestern New Mexico and the open plains of the southern Mexican tableland. It avoids hilly or mountainous areas, prefers flat, grass-dense land, and also avoids areas with trees and shrubs.

Breeding Season

The breeding season of the white-sided jackrabbit lasts at least 18 weeks, from mid-April to mid-August. Litters average around two young.

Juvenile Development

Juveniles have a soft, woolly coat early in life and reach sexual maturity quickly. Breeding does not occur for L. callotis within the first calendar year after birth.

Diet Composition

The diet of the white-sided jackrabbit consists primarily of grasses, including buffalograss, tobosagrass, fiddleneck, wolftail, blue grama, vine mesquite, ring muhly, wooly Indian wheat, and Wright buckwheat. The only major non-grass food item in their diet is sedge nutgrass.