White-footed mice (Peromyscus leucopus) are small, widespread rodents found across North America, from southern Canada to Mexico and the southwestern United States. These adaptable creatures inhabit various natural settings, including forests, woodlands, fields, and even suburban environments.
Appearance and Identification
White-footed mice have distinct physical characteristics. They typically have bicolored fur, reddish-brown to grayish-brown on their backs and faces, contrasting with pure white bellies and feet. Their total body length ranges from 150 to 205 millimeters (approximately 5.9 to 8.1 inches), including a tail nearly as long as their head and body combined, often appearing darker on top and lighter underneath.
These mice have relatively large, prominent ears and noticeably large, black eyes, distinguishing them from house mice. House mice typically have solid gray or light brown coats and smaller eyes. White-footed mice generally weigh between 15 to 25 grams (about 0.5 to 1 ounce).
Where They Live and What They Eat
White-footed mice prefer warm, dry forests and brushlands at middle elevations, but their adaptability allows them to inhabit a wide array of environments, including higher elevation forests, semi-deserts, and mixed forests. They construct nests in dry, sheltered locations such as hollow trees, abandoned bird nests, burrows, and around old stone structures or fallen trees.
As omnivores, their diet is diverse and varies with seasons and geographic location. They primarily consume seeds, nuts, and grains, with acorns being a favored food source. Their diet also includes fruits, berries, insects, and fungi. White-footed mice are active at night and do not hibernate, instead storing large quantities of food like seeds and nuts in their nests and caches to sustain them through colder months.
Ecological Impact and Health Concerns
White-footed mice fulfill several ecological roles within their habitats. They serve as a food source for a variety of predators, including owls, snakes, bobcats, weasels, and foxes, particularly due to their nocturnal activity. These rodents also contribute to forest regeneration by dispersing seeds and fungal spores, especially mycorrhizal fungi. They consume certain insect pests, such as the pupal stage of the spongy moth.
Despite their ecological contributions, white-footed mice are significant reservoirs for pathogens that can impact human health. They are well-known carriers of Borrelia burgdorferi, the bacterium responsible for Lyme disease. Infected blacklegged ticks (Ixodes scapularis) acquire the bacteria when feeding on infected mice, then transmit it to humans through subsequent bites. White-footed mice can also carry other pathogens, including hantaviruses, which, though rare, can cause severe illness in humans through contact with rodent waste.