Family: Leporidae, Hares and Rabbits view all from this family
Description Buffy gray or sandy above, peppered with black; white below. Tail has black stripe above, extending onto rump, with white border. Very long ears brownish with black tips. Very large hindfoot. L 18 1/425" (465630 mm); T 24 3/8" (50112 mm); HF 4 3/8"5 3/4" (112145 mm); E 3 7/85 1/8" (99131 mm); Wt 48 lb (1.83.6 kg).
Similar Species White-tailed Jackrabbit lacks black on top of tail. Antelope Jackrabbit has white lower sides; lacks black on ears.
Breeding 14 litters per year, each of 18 young (usually 24); births are year-round, but more frequent in milder weather. Gestation 4147 days.
Habitat Barren areas and prairies, meadows, cultivated fields; also areas where vegetation exceeds 2' (60 cm) in height.
Range Western U.S., from sc Washington south to California, east to Nebraska, w Missouri, and Texas. Introduced in New Jersey and Kentucky.
Discussion This most abundant and widespread jack was originally called a "jackass rabbit," after its very large ears. Like other jacks, it is not really a rabbit but a hare, as its young are born well furred and with their eyes open. By day, it generally rests in dense vegetation or in a form, becoming active in late afternoon. Somewhat social, it often feeds in loose groups. In summer, it eats many kinds of plants, favoring alfalfa when available; in winter, it depends on woody and dried vegetation. When alarmed, it remains very still, but may move its ears to catch sounds. It rarely walks, but hops 5 to 10 feet (1.53 m) at a time, up to 20 feet (6 m) when panicked, and reaches speeds of 30 to 35 mph (5055 km/h) over short distances. When it runs at moderate speeds, every fourth or fifth leap is exceptionally high, allowing it a better view of surroundings or a pursuing predator; at top speed there are no such special jumps. When escaping from a predator, it flashes the white underside of its tail, perhaps alerting other jacks to danger and confusing its enemy. After fleeing a short distance, it stops and looks back, evidently to see if it is still being pursued, and may then give a danger signal by thumping its hindfeet. It can swim, dog-paddling with all four feet. The young are born in a relatively deep form lined with hair from the mothers breast. The mother then places them in separate forms, thus decreasing a predators chance of taking her entire litter. To avoid attracting attention, she keeps her distance by day but comes several times a night to nurse. The young can fend for themselves in less than a month. Generally silent, these hares can squeal and give distinctive calls when fighting or distressed and when assembling their young. Coyotes, Bobcats, foxes, hawks, owls, and snakes are predators.

