Family: Dipodidae, Jumping Mice view all from this family
Description Brownish back; yellowish sides; white belly. Long tail with tip usually not white. 1 small molariform tooth precedes 3 large molariform teeth. L 7 3/8"–10 1/8" (187–255 mm); T 4 1/4–6 1/8" (108–155 mm); HF 1 1/8–1 3/8" (28–35 mm); Wt 3/8–1 oz (13–28 g).
Endangered Status The Preble's Meadow Jumping Mouse, a subspecies of the Meadow Jumping Mouse, is on the U.S. Endangered Species List. It is classified as threatened in Colorado and Wyoming. The decline in this subspecies' numbers can be primarily attributed to the loss and modification of its habitat by agricultural, residential, commercial and industrial development.
Similar Species Woodland Jumping Mouse lacks a reduced first molariform tooth; tip of its tail is white. Western Jumping Mouse generally occurs west of the range of this species.
Breeding Births peak in June, July, and August; most females produce 2 litters of 2–9 (usually 5 or 6) young per year; females born late the previous year probably produce 1 litter in July; gestation 19 days.
Habitat Mainly moist fields; but also brush, brushy fields, marshes, stands of touch-me-not (Impatiens), and woods with thick vegetation, especially where Woodland Jumping Mouse does not occur.
Range Southern Alaska and across most of southern tier of Canadian provinces; e Wyoming east through ne U.S. and west and south to ne Oklahoma and ne Georgia.
Discussion When startled from a hiding place, the Meadow Jumping Mouse may take a few long jumps of 2 to 3 feet (60–90 cm), then shorter ones, but generally it soon stops and remains motionless, which is its best means of eluding predators. By the end of October, nearly all individuals of this species have retired to hibernation nests of shredded grass in a protected place, such as under a board or clump of grass, or in a bank, mound, hollow log, or other raised area. Apparently many later-born, smaller mice, unable to accumulate adequate fat reserves, perish during hibernation. In spring, caterpillars, beetles, and other insects constitute about half of this rodent’s diet. It feeds on the seeds of grasses and many other green plants as they ripen, either by cutting off grasses at the base, then pulling the stem down to reach the head, or by climbing a stalk, cutting off the head, and carrying it to the ground in its mouth. In summer and fall, the subterranean fungus Endogone forms about an eighth of this animal’s diet. The Meadow Jumping Mouse stores no food, but in the two weeks before entering hibernation, it puts on about 1/4 ounce (6 g) of fat. Males emerge first, in late April or early May; one to two weeks later, females emerge and the first mating takes place.
