Deer Mouse

Peromyscus maniculatus (Wagner)

Color photo by Robert M. Timm.
   Copywrite 2001. All rights reserved.

Description:   The deer mouse is the smallest and most abundant member of its genus in Kansas. It can be distinguished from other members of its family by: 1) rather small size, 2) tail somewhat shorter than the head and body, 3) warm brown to grayish-brown upperparts with an ill-defined longitudinal mid-dorsal band of black or dusky guard hairs, 4) finely-haired tail with a narrow, well-defined dark dorsal stripe that is sharply set off from the white ventral portion, 5) prominent, naked, pale ears with black edges, 6) white feet, 7) lack of grooved incisors, and 8) short hind feet (20 mm or less). Juveniles are darker and more grayish dorsally than adults. Size:   Adults may attain the following dimensions: total length 125-164 mm; tail 43-72 mm; hind foot 16-20 mm; ear 13-17 mm; weight 18.5-25 grams.

Range and Habitat:   There are two subspecies of the deer mouse in Kansas, Peromyscus maniculatus luteus Osgood in the western half (squares) and Peromyscus maniculatus bairdii (Hoy and Kennicott) in the eastern half (circles). They are both found in open grassy areas ranging from sparse, short vegetation to climax grasslands, but often inhabit woodlands and forests as well. Deer mice are probably the most abundant and widely distributed of all Kansas mammals.

Reproduction:   Deer mice mainly breed in April and August, but are known to breed throughout the year. After a gestation period of 23 to 27 days, one to nine (usually four or five) young are born naked and pink with eyes closed and ears folded. They acquire hair on their second day and their ears unfold. In six days some of their teeth are present, and in two weeks their eyes are open and their body is well-furred. In 25 to 28 days the young are weaned, and in one and one-half months they are capable of breeding. The female has six nipples, two pectorally and four inguinally.

Habits:   The deer mouse is alert, sensitive and "nervous." It is active throughout the year, mainly at night, but occasionally during the day. In winter small mammal trails on snow are usually caused by this species, although they are not active beneath the snow blanket. This mouse is capable of climbing, but spends most of its time on the ground, sometimes using the runways of other small mammals. They forage by slowly walking, but run or jump when speed is required. Their large nests are most commonly placed on the ground under the protection of logs, rocks, in crevices or a burrow. The nest is made of grasses or coarse plant stems and lined with soft materials, especially shredded plant fibers. In winter, deer mice may become social, and several may live together in one nest, but during the breeding season they live separately. Communication is by vocalization and stamping the feet, as well as by scent.

Food:   The deer mouse is omnivorous and eats seeds, nuts, fruits and insects. Food is stored in the burrow, especially in fall and winter.

Remarks:   The deer mouse has a multitude of predators including shrews, grasshopper mice, hawks, owls, skunks, weasels, raccoons, coyotes, foxes and snakes. Because of its availability as a prey species, predation pressure is reduced on less common kinds of small mammals. Young deer mice born in the spring seldom live beyond the summer of their second year, but in captivity may live for eight years.

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