Peromyscus maniculatusdeer mouse

Geographic Range

Peromyscus maniculatus is a North American species. It is distributed from the northern tree line in Alaska and Canada southward to central Mexico. It is absent from the southeastern United States and some coastal areas of Mexico within this range (Baker 1983).


Peromyscus maniculatus occupies many different ecological zones throughout its range. Deer mice can be found in alpine habitats, northern boreal forest, desert, grassland, brushland, agricultural fields, southern montane woodland, and arid upper tropical habitats. Also, P. maniculatus is found on boreal, temperate, and tropical islands. However, its most common habitats are prairies, bushy areas, and woodlands (King 1968).

Physical Description

Peromyscus maniculatus has a small body size, no longer than that of a house mouse. It is typically 119 to 222 mm long and weighs between 10 and 24 grams. Tail length is variable in different populations and ranges from 45 mm to 105 mm (Baker 1983). Woodland forms are typically larger and have larger tails and feet than prairie forms (LTER 1995). Peromyscus maniculatus has a round and slender body. The head has a pointed nose with large, black, beady eyes. The ears are large and have little fur covering them. The vibrissae are long and prominent. Peromyscus maniculatus has shorter forelimbs than hind limbs (Baker 1983).

Peromyscus maniculatus is grayish to reddish brown with white underparts. The fur is short, soft, and dense. The finely-haired tail is bicolored, the darker top half and the lighter bottom sharply differentiated. This differs from the other species of Peromyscus (Peromyscus leucopus), in which the separation of the two colors is less distinct. There are other characteristics that help distinguish P. maniculatus from the similar P. leucopus. Peromyscus maniculatus generally has hind feet that are 22 mm or less, while P. leucopus usually has hind feet 22 mm or more. Also, Peromyscus maniculatus is more richly colored with a brownish or tawny pelage, whereas P. leucopus tends to be more pinkish-buff or grayish, with scattered dark hairs (LTER 1995). These characteristics vary geographically, however, and in some areas the two species are extremely difficult to distinguish based on external morphology.

Like most murids, Peromyscus maniculatus has a dental formula of 1/1 0/0 0/0 3/3. Its molars are low-crowned and cuspidate. The third upper molar is less wide than the first two, while that of Peromyscus leucopus is approximately as wide as the first two (Baker 1983).

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    10 to 24 g
    0.35 to 0.85 oz
  • Range length
    119 to 222 mm
    4.69 to 8.74 in
  • Average basal metabolic rate
    0.219 W


Peromyscus maniculatus is polygynous (Kirkland and Layne 1989).

Female Peromyscus maniculatus are seasonally polyestrous with an estrous cycle of about five days. In the wild, reproduction may not occur during winter or other unfavorable seasons (LTER 1998). Females exhibit post-partum estrus and are able to become pregnant shortly after giving birth (Baker 1983). The gestation period of a nonlactating female deer mouse lasts from 22.4 to 25.5 days and 24.1 to 30.6 days in a lactating female (Kirkland and Layne 1989). Litter size is highly variable between populations. Peromyscus maniculatus may have litters containing from one to eleven young with typical litters containing four, five, or six individuals (Baker 1983). Litter size increases with each birth until the fifth or sixth litter and decreases thereafter (LTER 1998).

Peromyscus maniculatus is very altricial at birth but develops quickly. At birth, the deer mouse has a mass of about 1.5 g. The young are born hairless with wrinkled, pink skin, closed eyes, and folded over ear pinnae. Juvenile hair begins to develop on the second day after birth. On the third day, the pinnae unfold with the ear canal opening on the tenth day. Eyes open on the fifteenth day, and the young are weaned between day 25 and 35.

Conception can occur as early as 35 days, but the first estrus typically occurs around 49 days (King 1968).

  • Breeding interval
    Deer mice breed every three to four weeks during the warmer months and less frequently during the winter.
  • Breeding season
    Deer mice breed year round, but most breeding occurs during the warmer months.
  • Range number of offspring
    1 to 11
  • Average number of offspring
    4 to 6
  • Average number of offspring
  • Range gestation period
    22.4 to 30.6 days
  • Range weaning age
    25 to 35 days
  • Average time to independence
    35 days
  • Range age at sexual or reproductive maturity (female)
    35 (low) days
  • Average age at sexual or reproductive maturity (female)
    49 days

While nursing, the mother carries her young clinging to her nipples or one at a time in her mouth (Baker 1983). Once weaned, the young usually leave the nest and become independent of their mother, although sometimes the mother will tolerate their presence for longer periods. Often when the mother has a second litter, she forces the first litter out of the nest (King 1968).

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female


In captivity, P. maniculatus can live as long as eight years. However, in the wild, life expectancy is much shorter, usually less than a year (Baker 1983).


Peromyscus maniculatus is primarily a nocturnal species. Peromyscus maniculatus spends most of its time on the ground but it is also an adept climber. Activity centers around a nest and food cache. In terrestrial prairie subspecies, a nest is constructed just below ground level in its own burrow or one abandoned by another animal. Forest dwelling subspecies construct nests near the ground in stumps, logs, brush piles, tree cavities, reconstructed bird nests, tree bark, or even cottages or outbuildings. Nests are made of rounded masses of vegetable matter (as much as 100 mm in diameter) (Baker 1983).

A mature male, a few mature females, and several young constitute the basic social unit of the deer mouse. In the winter, groups of ten individuals or more of mixed sexes and ages may huddle together in nests to conserve heat. Also during winter, P. maniculatus may enter a daily torpor to reduce body temperature and conserve energy (Baker 1983).

  • Range territory size
    242 to 3000 m^2

Home Range

Home ranges of P. maniculatus range from 242 square meters to 3000 square meters. Home ranges of males are larger than females and show more overlap. Males use their home ranges for both access to feeding and nesting and also to reproductive females. Females use their home ranges for feeding, nesting, and rearing young.

Reproductive females are more aggressive in territory defense than males, and their territories overlap less, suggesting that they have a greater investment in territory defense than males. Intruding conspecifics will commit infanticide of young unattended by a female (Kirkland and Layne 1989).

Communication and Perception

Deer mice perceive their environment through keen senses of hearing, touch, smell, and vision. They communicate using tactile, visual, chemical, and auditory signals. They groom one another, posture, emit pheromones, mark their territories with scent, and make a variety of squeaky vocalizations. Sometimes when disturbed they drum their front paws rapidly up and down against a hard surface; this may serve as a warning signal to other deer mice.

Food Habits

Peromyscus maniculatus is omnivorous. It eats a wide variety of plant and animal matter depending on what is available, including insects and other invertebrates, seeds, fruits, flowers, nuts, and other plant products. Deer mice sometimes eat their own feces (coprophagy). In cooler climates, deer mice cache food in secret granaries during the autumn months (Baker 1983).

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • seeds, grains, and nuts
  • fruit
  • flowers


Deer mice are a staple in the diet of a wide variety of animals. Night-hunting predators, including snakes, owls, and various carnivorous mammals, are their biggest threat.

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Peromyscus maniculatus helps disperse the seeds of a number of species of plants, and also the spores of mycorrhizal fungi. In addition, deer mice are a food source for a wide variety of animals at higher trophic levels.

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Peromyscus maniculatus provides food for a number of carnivores, some of which are economically valuable fur-bearing mammals. Also, deer mice consume some insects that are considered pests (Baker 1983).

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

Deer mice consume seeds of valued forest trees, sometimes preventing regrowth. In addition, P. maniculatus can be destructive by raiding stored grains and other food supplies, gathering litter, and gnawing (Baker 1983). Finally, P. maniculatus is a host for strain of hantavirus called Sin Nombre virus (also called Four Corners or Muerto Canyon virus). This virus, which can be contracted by humans from deer mice, causes an often fatal disease termed hantavirus pulmonary syndrome (Rowe et al. 1995).

  • Negative Impacts
  • injures humans
    • carries human disease
  • crop pest
  • household pest

Conservation Status

Peromyscus maniculatus is an abundant species, often among the most abundant mouse species of certain areas (LTER 1998). Densities can reach 11 mice per acre (Baker 1983). Quantity and quality of foods, availability of water, number and distribution of nest sites, architecture of living and dead vegetation, and depth and density of litter are some ecological factors proposed to affect the density of P. maniculatus. However, only the availability of food has been studied in enough detail to show it has an effect on population density (Kirkland and Layne 1989).

Other Comments

In Michigan, there are three distinct subspecies of deer mice. Peromyscus maniculatus maniculatus is found only on Isle Royale. Peromyscus maniculatus gracilis is found in forests of the northern Lower Peninsula and the Upper Peninsula, and Peromyscus maniculatus bairdii is found in open areas (preferably plowed or cultivated fields, early stages of grasslands, or along lake shores) of the Lower Peninsula and the southwestern Upper Peninsula. Peromyscus maniculatus gracilis and P. m. bairdii differ quite noticeably. Peromyscus maniculatus gracilis has a longer tail, ears, skull, and hind foot than P. m. bairdii. It is interesting that despite having sympatric ranges these subspecies do not interbreed. One possible explanation for this is the difference in habitat preference of the two species, limiting their contact (Baker 1983).


Allison Poor (editor), University of Michigan-Ann Arbor.

Andrew Bunker (author), University of Michigan-Ann Arbor.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map


living in the southern part of the New World. In other words, Central and South America.

World Map


uses sound to communicate


living in landscapes dominated by human agriculture.


young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.


Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


union of egg and spermatozoan


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


having the capacity to move from one place to another.


This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


an animal that mainly eats all kinds of things, including plants and animals


chemicals released into air or water that are detected by and responded to by other animals of the same species


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.


having more than one female as a mate at one time

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"


living in residential areas on the outskirts of large cities or towns.


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


Living on the ground.


defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


uses sight to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year


Baker, R. H. 1983. Michigan Mammals. Wayne State Univerisity, Detroit, Michigan.

King, J. A. 1968. Biology of Peromyscus (Rodentia). First Edition. The American Society of Mammalogists, Stillwater, Oklahoma.

Kirkland, G. L. and Layne, J. N. 1989. Advances in the Study of Peromyscus (Rodentia). Texas Tech University Press, Lubbock, Texas.

LTER (Sevilleta Long-Term Ecological Research Project). 1998. University of New Mexico.

Rowe, J. E., St. Jeor, S. C., Riolo, J., Otteson, E. W., Monroe, M. C., Henderson, W. W., Ksiazek, T. G., Rollin, P. E., and Nichol, S. T. 1995. Coexistence of several novel hantaviruses in rodents indigenous to North America. Virology 213 (1): 122-130.