Peromyscus crinitus
(Canyon Mouse):

Description:
Canyon mice are small, grayish to yellow-brown above and whitish below. Its distinctive tail is long, more than half its total body length, darkish on top and whitish below, but heavily furred with a tufted tip. Their ears are smaller than the deer mouse. Total length is 6 ¼ to 7 ½ inches (152-205 mm), tail length is 2 ¼ to 3 ¾ inches (63-97 mm) and they weigh ¾ to 1 5/8 ounce (20-46 g).

Range:
From eastern Oregon, southwestern Idaho, and southwestern Wyoming, south to northwestern Sonora and eastern Baja California Norte, west to northeastern and southeastern California, and east to western Colorado and northwestern New Mexico.

Habitat:
This species is obviously found in canyons, in rocky habitats such as gravelly desert pavement, talus, boulders, cliffs, and slickrock. The vegetation type does not seem to be important. They have been documented in hot, dry deserts near sea level to canyons and rocky habitat in mountains up to 10,000 feet (3000 m).

Diet:
Eats seeds, insects, and green vegetation, depending on availability. In Idaho, diet includes hackberry, rose, currant seeds, and insects.

Ecology:
Canyon mice are active throughout the year. They are primarily nocturnal, and may exhibit diurnal torpor in response to food and water deprivation. They may enter torpor at low environmental temperatures that are less than 42 o F (5° C). They can apparently survive without access to water. Maximum population density has been estimated at 3 per 2.5 acres (1 ha) in California, 27 per 2.5 acres (1 ha) in the Grand Canyon, and 43per 2.5 acres (1 ha) in southeastern Utah. Little is known about the ecology of this species in Idaho.

Reproduction:
Nesting occurs in rocks, even on cliffs. Gestation lasts about 25 to 31 days, and newborn young are heavier than most other mice. Young are altricial at birth, and have a slower postnatal development; they are not weaned until about 28 days, which is later than most other mice. litter size varies from 2 to 4 young per litter (average 3 in southern California and northern Utah). Females may produce multiple litters annually. Young are sexually mature and first breed at 4 to 6 months.

Conservation:

Status:	Unprotected nongame species
Global Rank:	G5
State Rank:	S3