Deer Mouse (Peromyscus maniculatus)

County List:

Rule:

Forested or Nonforested Landscapes

1st alternative:
      (Any Forested Upland (Any Size Class))
      or (Any Forested Lowland (Any Size Class))
      or Treed Bog
   containing:
      Mast 
      and Dead Down Woody Debris 
      and (Snags or Living Cavity Trees)
   adjacent to:
      Edge

2nd alternative:
      Upland Brush
      or Grass
      or Savanna
      or Any Cropland
      or Coastal Dunes
   containing:
      Mast

Habitat List:

view size class definitions

Literature:

There are four subspecies of deer mouse in the Great Lakes region.

In the Great Lakes basin, the prairie deer mouse dwells in open areas, such as meadows, cultivated fields, pastures, and sand dunes along the lakes. Our other subspecies in contrast, favor forested habitats, but they also venture into shrubby areas, regenerating clear-cuts, and recent burns.

In grasslands, this rodent generally hides its nest in a small burrow, but woodland dwellers may also nest in a rotting stump, under a log, in a tree hollow, or snug inside a cabin.

Those living in wooded habitats are active climbers, spending as much time in trees as on the ground.

This species is a true omnivore, with animal flesh accounting for 15-55% of the diet even in winter. Although it sometimes eats earthworms, insects are preferred, especially crickets, springtails, beetles, moth larvae, and grubs. Plant food is largely seeds gleaned from foxtail, crabgrass, ragweed, sorrel, and other herbs. In agricultural areas, corn, soybeans, and wheat are common foods, whereas berries, wild cherries, nuts, and conifer seeds are important in forests. Fresh food is sparse in winter, and the mouse supplements its meager find with seeds cached during the autumn.

Habitat: Mainly occurs in interiors or along edges of coniferous or mixed forests, along field borders, stone walls, in out-buildings near areas with small trees and dense ground cover. Uses recent forest clearcuts.

Habitat Preferences: Peromyscus maniculatus bairdii. This prairie subspecies of deer mouse probably was an unusual mammal in extreme southern Michigan in presettlement days. Its major habitats then were perhaps sandy beaches along lake shores, edges of marshes, openings in oak woodlands in southwestern counties or situations where severe fires had obliterated woody cover. After settlement, this plains-adapted mouse was able to extend its range slowly eastward, thriving in the early vegetation stages produced by deforestation and agriculture. Ultimately, this Midwestern deer mouse reached the Atlantic coastal states of New York and Maryland. It progressed north in cleared lands of Michigan's Lower Peninsula to reach northernmost Emmet County. Its entry into the southwestern part of the Upper Peninsula has been less obvious than that of another prairie dweller, the thirteen-lined ground squirrel. This deer mouse's preference for early successional vegetation produced by agriculture has caused it to be called the farmer's mouse. It is closely associated with crop and recently-fallow lands. Beckwith and others have shown that the prairie subspecies of the deer mouse is common in fallow agricultural land when vegetation is in the annual-biennial stage of successional growth. When the successional process continues to a strictly perennial grass stage, the deer mouse decreases and the meadow vole becomes common. Because of this rodent's proclivity for disturbed environments in the earliest plant associations from open ground to mature forests, its distribution in Michigan has both a mosaic and changeable pattern. Its preferred environment, if not re-disturbed, will go through a series of plant changes producing habitats progressively unfavorable and causing the decline and ultimate disappearance of the animal. Michigan Mammalogists have reported this deer mouse in open grassy fields in Kalamazoo County, on gravel and sandy beaches in Charlevoix and Huron counties, in open fields in Washtenaw County, on sandy beach under driftwood in Berrien County, in fields near marshes and tamarack swamps in Cass County, in wheat, oats, and alfalfa, and field-shocked corn in Clinton County, in bare places and sparse vegetation in Livingston County, in bluegrass association in Livingston County, in sparse numbers on dunes, in orchards, and in newly invaded shrub seres in Grand Traverse County, and based on studies by classes in Mammalogy each autumn on the Michigan State University campus, along disturbed railroad right-of-way and in fields of cultivated plants.

Peromyscus maniculatus gracilis: The subspecies of deer mouse occurring in northern Michigan is, in marked contrast to the more southern P. m. bairdii, a woodland dweller, widespread in the Upper Peninsula and on many wooded islands in the Great Lakes. In the upper third of the Lower Peninsula this long-eared and long-tailed deer mouse occupies suitable forested areas. In presettlement times, P. m. gracilis could conceivably have occurred in forested areas in southern Michigan. However, Hooper does not believe that was the case because 1) some relic populations should still remain in selected forested areas of southern Michigan, but none have been found and 2) there are no museum specimens attributable to this subspecies from southern Michigan among the collections preserved from the last half of the nineteenth century. Consequently, it is thought that proper northern hardwood environments, to which this rodent is adapted, exist no further south in Michigan than at a line of latitude drawn through the mouth of Saginaw Bay. In contrast, the prairie-dwelling subspecies, P. m. bairdii, has taken advantage of clearing operations to spread northward to the Straits of Mackinac, with the result that the two ranges remain ecologically separated but geographically interdigitated. As Hooper stated, in Michigan P. m. gracilis thrives best in dense upland forests of beech, maple, yellow birch, and other hardwoods. Other observers have recorded P. m. gracilis in virgin and second-growth hardwoods, bogs, brush, jack pine, dune heath, swamp, and marsh edge in Charlevoix County, in mature upland forest in Marquette and Baraga counties, in a variety of forest and shrub habitats in Gogebic and Ontonagon counties, in mixed grass and weeds on mine tailings in Houghton County, in mature forest in Marquette County, in upland hardwoods and conifer swamps in Alger and Schoolcraft Counties, in various woody habitats, grassy meadows, and ground juniper on Beaver Island and other island environments, and in isolated woodlots and surrounding open lichen-grass associations of the Kingston Plains in Alger County. Forest fires and the varied habitats produced in the prolonged period of vegetation re-growth do not seem to have been major deterrents to the survival of woods-dwelling deer mice. In fact, a Minnesota study shows that this mouse was the most abundant small mammal for the first seven years after a burn. Further, in Alger County, Verme and Ozoga noted that deer mice numbers increased in conifer swamps following successional changes resulting from both strip clear-cutting and the burning of the resultant slash.

Peromyscus maniculatus maniculatus: This subspecies of deer mouse occupies most of the same habitat on Isle Royale as does P. m. gracilis on the Michigan mainland and on Beaver Island. In a study made by Johnson et al., this rodent occurred most commonly in boreal (conifer) forest, and in smaller numbers in second growth resulting from forest fires (which had taken place at least 32 years previous) and in mature sugar maple-yellow birch woodland. The authors concluded that the deer mouse could be found on all island habitats except wet sites.

Density and Movements: In northern Michigan, reported densities were as high as 43 woodland deer mice per acre in mature upland forest in Marquette and Baraga counties; 36 per acre in mature maple forest in Marquette County. Densities were heavier in upland hardwoods than in conifer swamps in Alger and Schoolcraft counties. In a study on the Keweenaw Peninsula, Nofz found woodland deer mice in summer to be most dense in sugar maple habitat, less dense in birch-aspen, old field and swamp, with lowest density in spruce-fir. High numbers may represent local extremes, since densities over large areas usually seem no greater than 11 per acre at peak period of the year.

Associates: Association with the White-footed Mouse - P. leucopus. In the southern areas where the prairie deer mouse (P. m. bairdii) occurs, these two species are in contact primarily where brush lands or trees occupied by the white-footed mouse are bordered by the cleared or disturbed open lands mostly preferred by the deer mouse. Although this deer mouse rarely enters the brush and forest habitat of the white-footed mouse, the latter species does share with the deer mouse the early seral stages of cultivated fields consisting of weeds, crops, and annual grasses and, of course, eventually replaces the deer mouse when these early successional stages give way to shrublands. Master even suggests that these two species may compete for space in this habitat. In northern forested areas, there is a close interaction between the white-footed mouse and the woodland deer mouse. Although these two rodents have been captured in similar areas and even in adjacent traps where their ranges overlap from Minnesota and Wisconsin to Vermont, Maine and Quebec, there is a tendency, in areas where they occur together, for the more aggressive white-footed mouse to occupy dry, exposed, and more open hardwood forests while the deer mouse prefers the moist, secluded, and cool coniferous forest interiors. Also, in areas where both occur, the woodland deer mouse usually nests in trees and the white-footed mouse on the forest floor. However, when only one of these two species occurs in such habitat, it may very well occur in hardwoods, in mixed hardwoods and conifers, and in conifers. To date there has been little evaluation of the interaction between these two forest rodents where they occur together in the northern part of Michigan's Lower Peninsula.

Food Habits: Deer mice have low-crowned, cuspidate teeth, adapting them to a general diet of insects, other invertebrates, seeds, fruits, flowers, and other plant products - foods produced in the warm, growing period of the Michigan annual cycle. During the cold, non-growing period of late autumn, winter and early spring, caches of staples are necessities, especially when individual deer mice may eat between 2.0 and 3.5 grams of food per day.

Behavior: The terrestrial prairie subspecies usually constructs a nest just below ground level in its own burrow or in one abandoned by another small mammal. Nests can also be found under debris, boards or other objects discarded by humans, and in shocked field crops. The nests of the forest dwelling deer mice are placed near the ground, in stumps, logs, in brush piles, in tree cavities, under tree bark, in reconstructed bird nests, in burrows, in cottages or outbuildings.