White-footed Mouse
Order Rodentia : Family Muridae : Peromyscus leucopus (Rafinesque)

Description. A medium-sized, short-tailed, white-footed mouse; tail about 43% of total length, sparsely haired, darker above than below but usually not sharply bicolor; upperparts cinnamon rufous mixed with blackish; sides paler, with less admixture of black; underparts and feet white, the "ankle" slightly brownish. External measurements average: total length, 173 mm; tail, 78 mm; hind foot, 21 mm. Weight, 18-32 g, averaging about 22 g. Most easily confused with P. gossypinus and P. maniculatus; P. leucopus differs from the former in smaller size, shorter body, lighter weight, and brighter colors; from the latter in less hairy and not sharply bicolor tail, usually shorter pelage, and lack of whitish tufts at base of ears.

Distribution in Texas. Statewide.

Habits. In the main, these mice are woodland dwellers, a fact that is best illustrated along the western border of their range where they are restricted almost entirely to creek and river bottoms. As one progresses eastward, the mice are found in a progressively greater variety of habitats. In east-central Texas, they are most abundant in bottom lands, less so in post oak uplands and almost completely absent from prairie lands. They are adept at climbing and often den in hollow trees out of danger from overflow waters. In areas not subject to inundation, they live in dens under logs, in stumps, brush piles, burrows, or buildings.

In much of its range, this mouse is one of the commonest of small mammals. In Brazos County, the population of this mouse is exceeded only by that of the cotton rat. In 3,483 trap-nights, 161 cotton rats and 121 white-footed mice were captured; a ratio, respectively, of 21.6 and 28.7 trap-nights per animal. The maximum home range of adult males is about 0.2 ha, that of adult females about 0.15 ha. The mice seldom travel more than 50 m once they are established in suitable quarters. The dispersal of the population generally is accomplished by movements of the unestablished young mice.

The food of white-footed mice is varied, but their chief reliance is seeds and such nuts as acorns and pecans. When food is abundant, they store it in and about their nests for winter use. Caches of "several quarts" have been reported. Like squirrels, these mice have internal cheek pouches in which they can place food for transport to caches. In spring and summer they feed to some extent on fruits and on insects, snails, and other invertebrates.

In east-central Texas, gravid females have been captured in nearly every month of the year. Litter size varies from one to six, averaging about four. Captive females have produced as many as 10 litters and 45 offspring in 1 year, but in the wild the number of litters appears to be four or five. The gestation period is from 22 to 25 days in nonlactating females and 23 to 37 days in those that are lactating. At birth the young are blind, pink, and weigh about 2 g. They become pigmented dorsally in the first 24 hours, their eyes open in about 13 days, and they are weaned at the age of 22 or 23 days if the mother is expecting a new family; if otherwise, they may nurse as long as 37 days. Young females mature sexually at the age of 10 or 11 weeks and may bear their first litters at the age of 13 or 14 weeks. Usually, females born in the spring rear one or two litters themselves before winter sets in. They seldom live to be more than 18 months old in the wild.

Where numerous in an area, they can become destructive of stored and shocked grains and consequently need to be controlled. But in most places they are of little or no economic significance if such natural predators as owls, snakes, and weasels are not destroyed.

Photo credit: John L. Tveten, courtesy of Texas A&M University Press.