Zapus princeps
(Western Jumping Mouse)

Order: Rodentia
Order Description:Rodents
Family: Zapodidae
Family Description:
Jumping Mice

The western jumping mouse is a beautiful little mammals with a very long tail, dark brown hair on the dorsal surface, white underneath, and yellowish-brown on the sides from the tip of the nose to the base of the tail. The tail is sparsely haired and scaly. The long tail and large hind feet accommodate its hopping (saltatorialClick word for definition) locomotion. Total length is 7.2 to 9.2 inches (180-230 mm), tail length is 4.6 to 5.6 inches (115-138 mm), and they weigh 0.6 to 0.8 ounce (18-24 g).

From southeast Yukon Territory, east to southwestern Manitoba, south to New Mexico through Rocky Mountains, and south (through eastern Washington and Oregon) to California Sierras.

Found in mountain meadows, along banks of streams and ponds, in marshes, and in dense cover of tall grasses and herbs. In Idaho, prefers wet meadows, bogs, and streamside habitats in forest and subalpine areas. Idaho study in grand fir stands found species preferred willow-alder thickets in mid-successional stages.

Feeds on insects and other invertebrates in spring. In midsummer, consumes mostly grass seeds and some berries.

NocturnalClick word for definition. HibernatesClick word for definition/aestivatesClick word for definition. Adult may enter hibernationClick word for definition in September or October. Throughout winter, periods of hibernation alternate with arousal from torporClick word for definition. In eastern Wyoming, emergence from hibernation occurs mid-May to mid-June; in Utah at high elevations, emergence may not occur until late June or July. When inactive, occupies burrow in well-drained mound, elevated bank, or spherical surface nest. Utah study reported home range averaged 0.2-0.6 ha in different areas in different years. Adult density was 8-32/ha in different areas. Individuals are primarily solitary, are good swimmers, and are known to use erratic running patterns to evade predators.

Breeding occurs soon after females emerge from hibernation. GestationClick word for definition lasts 18 days. Most young are born late June-early July. Female apparently produces only 1 litter/yr. litterClick word for definition size is estimated at 2-7 young (average 5). Some females bear first litter at 1 yr.

Status: Unprotected nongame species

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Important State References:
Scrivner, J.H. and H.D. Smith. 1984. Relative abundance of small mammals in four successional stages of spruce-fir in Idaho. Northwest Sci. 58:171-176.

Information written by Donald Streubel,© 2000
Map image provided by
Stephen Burton,© 2000
Design by Ean Harker©1999, 2000.