BIOLOGICAL DATA AND HABITAT REQUIREMENTS
WILDLIFE SPECIES: Peromyscus maniculatus | Deer Mouse 



TIMING OF MAJOR LIFE HISTORY EVENTS : 
Deer mice are active year-round, although activity is minimal in cold
and/or wet weather.  They are nocturnal [79].

Breeding Season:  In most parts of their range deer mice breed from
March to October [86].  Deer mouse breeding tends to be determined more
by food availability than by season per se.  In Plumas County,
California, deer mice bred through December in good mast (both soft and
hard masts) years but ceased breeding in June of a poor mast year [3].
Deer mice breed throughout the year in the Willamette Valley, but in
other areas on the Oregon coast there is usually a lull during the
wettest and coldest weather [79].  In southeastern Arizona at least
one-third of captured deer mice were in breeding condition in winter
[17].  In Virginia breeding peaks occur from April to June and from
September to October [130].

Nesting:  Female deer mice construct nests using a variety of materials
including grasses, roots, mosses, wool, thistledown, and various
artificial fibers [79].

Gestation, Litter Size, and Productivity:  Peromyscus species gestation
periods range from 22 to 26 days [72].  Typical litters are composed of
three to five young; litter size ranges from one to nine young.  Most
female deer mice have more than one litter per year [79].  Three or four
litters per year is probably typical; captive deer mice have borne as
many as 14 litters in one year.  Males usually live with the family and
help care for the young [86].

Development of Young:  Deer mice are born blind, naked, and helpless;
development is rapid.  Young deer mice have full coats by the end of the
second week; their eyes open between 13 and 19 days; and they are fully
furred and independent in only a few weeks [79].  Females lactate for 27
to 34 days after giving birth; most young are weaned at about 18 to 24
days.  Young reach adult size at about 6 weeks and continue to gain
weight slowly thereafter [72].

Age of first estrus averages about 48 days; the earliest recorded was 23
days.  The youngest wild female to produce a litter was 55 days old; it
was estimated that conception had occurred when she was about 32 days
old [72].

Dispersal:  Deer mouse pups usually disperse after weaning and before
the birth of the next litter, when they are reaching sexual maturity.
Occasionally juveniles remain in the natal area, particularly when
breeding space is limited [126].  Most deer mice travel less than 500
feet (152 m) from the natal area to establish their own home range
[114].

Longevity and Mortality:  Most deer mice in the wild have very short
life spans, usually less than 1 year [79].  O'Farrell [88] reported that
a population of deer mice in big sagebrush/grasslands had completely
turned over (e.g., there were no surviving adults of the initial
population) over the course of one summer.  One captive male deer mouse
lived 32 months [79], and there is a report of a forest deer mouse that
lived 8 years in captivity (another mouse was fertile until almost 6
years of age) [31].


PREFERRED HABITAT : 
Habitat Preferences:  In some forests and woodlands, disturbance appears
to favor deer mice although they are also common in climax (old-growth)
associations [3].  In Oregon and Washington Douglas-fir stands, deer
mouse abundance was negatively correlated with proportion of coarse
fragments in the soil.  In Washington the highest deer mouse numbers
occurred in moderately moist, old-growth Douglas-fir, but the second
highest population was in a clearcut [26].  In western Oregon deer mouse
capture rates decreased substantially with distance from streams in
mature Douglas-fir forest [81].  In the northern Sierra Nevada deer mice
are primarily forest-dwelling and are not as abundant in brushlands.
However, this differential distribution varies with elevation.  At 2,200
feet (670 m) elevation, deer mice were less common in forests than
brush, from 3,500 to 5,000 feet (1,067-1,524 m) elevation deer mice were
more common in forests than brush, and above 5,000 feet (1,524 m) deer
mice were the only mouse species in sagebrush (Artemisia spp.)
communities.  They were less abundant in forests above 5,000 feet than
in forests at lower elevations [60].

Preference for disturbed habitats has also been reported for some
sagebrush and grassland communities.  In Nevada big sagebrush-antelope
bitterbrush range, deer mouse captures were positively associated with
relatively high amounts of litter, shorter shrubs, and greater shrub
intersection [87].  In western South Dakota deer mice are associated
with black-tailed prairie dog (Cynomys ludovicianus) towns, occurring in
and near towns in higher abundance than in surrounding grasslands [104].
In grasslands and adjacent vegetative communities, deer mice are usually
more abundant in early seral and/or severely disturbed areas than in
undisturbed communities [37].  In Nebraska sandhills prairie deer mice
were found more often in grass-forb communities than in sagebrush,
grass, or on open ground, but were common in all types [74].  Geier and
Best [45] ranked the deer mouse as selective of particular habitats in
Iowa riparian areas; deer mice were positively associated with forb
cover and negatively associated with mean length of downed logs, plant
species richness, vertical stratification, and grass cover.

A lack of preference for habitat features has been described for deer
mice in several communities.  On the Oregon coast deer mice occupy all
habitats from beach to forest [79]; a similarly wide distribution of
deer mice was also found on islands off the coast of British Columbia
[9,77].  In Colorado deer mice were equally prevalent in stands
dominated by aspens (Populus spp.) and stands dominated by conifers
[102].  In Illinois deer mouse abundance was not correlated with any of
the tested habitat parameters:  bare ground, annual cover, perennial
cover, grass cover, woody vegetation, and vegetative density [3].  In
New Hampshire forests deer mice were captured in nearly all areas,
showing no preference for a particular vegetative community [47].  On
Mount Desert Island, Maine, deer mice were found in both coniferous and
deciduous forests [40].

Habitat preferences that are not apparent at the species level may be
resolved by closer attention to taxonomy.  Different deer mouse
subspecies are strongly associated with habitat parameters.  For
example, the prairie deer mouse avoids wooded areas, even if the surface
layer is grass-dominated.  It is likely that deer mouse subspecies
replace other deer mouse subspecies over the course of succession [3].

Logging Effects:  Logging frequently has a positive effect on deer mouse
populations although some studies report no change or negative effects
on deer mouse abundance.  Increased cover in slash and increased
production of seed by annuals probably contribute to the positive
effect.  The following studies all report increased deer mouse
populations following logging or logging and slash-burning:

Oregon:  in clearcuts in Douglas-fir forests; deer mice were present 
   in all successional stages with no strong correlation between 
   habitat features and deer mouse abundance [25,44,58,59]
British Columbia:  in 15- to 17-year old clearcuts in Pacific silver 
   fir (Abies amabilis)-western hemlock (Tsuga heterophylla)-mountain
   hemlock (T. mertensia); deer mice were the most abundant rodents 
   in all stages [126] 
northwestern California: in clearcut and slash-burned Douglas-fir [123]
Wyoming:  in lodgepole pine, Douglas-fir, and climax Engelmann spruce
   (Picea engelmanii) stands [19] 
central Colorado:  in small circular clearcuts in Engelmann spruce-subalpine
   fir (Abies lasiocarpa) stands [103]
Southwest:  in ponderosa pine; deer mouse abundance increased directly with 
   increased amounts of slash [22] 
New Mexico and Arizona:  after fall thinning of pinyon-juniper woodlands;
   there was a negative correlation between juniper stocking density and deer 
   mouse abundance [2]
Arizona:  deer mouse abundance was positively correlated with slash 
   in pinyon-juniper woodlands [68] in harvested ponderosa pine where
   cull logs and large diameter limbs were left scattered rather than
   piled [46] 
West Virginia:  in clearcut plots in coniferous forest [66]

The following studiess report no change or decreased deer mouse numbers
with logging:

West Virginia :  in clearcuts in deciduous forests; although deer mice
   decreased after logging, they were the most abundant  rodent on
   all plots [66]; deer mice were slightly more abundant in older hardwood 
   stands than in other stages including recently harvested areas, but 
   were present in all seres [16]
Alaska:  deer mice were more numerous on timbered habitat than in 
   clearcuts; however, traplines in clearcuts were 2,000 feet (600 m) 
   from the nearest tree seed source [53]

Grazing Effects:  In northern Nevada and southern Idaho high elevation
riparian areas within big sagebrush habitat, there were more deer mice
in grazed areas than in ungrazed areas on a sagebrush-dominated study
site; however, on an aspen and willow (Salix spp.)-dominated study site
there were more deer mice on the ungrazed site than the grazed site
[23].  In another study there was little difference in deer mouse
abundance between grazed and ungrazed plots in big sagebrush-antelope
bitterbrush/Idaho fescue (Festuca idahoensis) range in Nevada [87].  In
northeastern Colorado riparian areas, deer mice were negatively
associated with grass cover, litter, and shrub presence [99].  In New
Mexico deer mice were common in both grazed and ungrazed montane
riparian areas [118].  Kaufman and others [62] predicted that
grassland-inhabiting, fire-positive wildlife species such as the deer
mouse would have higher relative abundance in moderately- to
heavily-grazed grasslands than on lightly-grazed or ungrazed grasslands
because of the lesser amount of litter on heavily-grazed areas [63].
Deer mouse abundance was higher on grazed sagebrush/grassland than on
ungrazed sites [11].

Other Vegetation Management:  Application of herbicide to control shrubs
and weeds had little effect on deer mouse population in logged western
hemlock-western red-cedar-Douglas-fir plots in British Columbia [117].

Home Range:  Stickel [114] compiled studies on deer mouse home ranges
across North America.  Most studies concluded that the size of the deer
mouse home range was directly related to food supply, and varies with
season.  There is often, but not always, an inverse relationship between
deer mouse population density and home range size.  The smallest average
home range, 0.08 acre (0.032 ha), was recorded in Arkansas young oak
(Quercus spp.)-pine forest, and the largest average, 4.66 acres (1.2
ha), was in New Mexico mesquite (Prosopis spp.)  range [114].  Deer mice
use and maintain several home sites or refuges within the home range.
Prairie deer mice travel over a different area within the home range on
successive nights, returning to the nest on the same path used for the
outward trip.  The extent of travel and intensity of use of the home
range varies with habitat change and loss or gain of conspecific
neighbors.  Home range fidelity is fairly strong.  At least half of deer
mice on an Alberta study site that were displaced more than 5,000 feet
(1,500 m) from the capture site returned to the home area [119].  Adults
shift home ranges in response to habitat alteration or disturbance.  One
adult female, caught four times within a 75-foot (26 m) radius, shifted
her home range 1,000 feet (305 m) [114].

Deer mice have considerable tolerance of conspecifics; individuals have
overlapping ranges and sometimes associate in nests, particularly in
winter [5,72].  In South Dakota grasslands deer mice congregate in
groups of 15 or more during winter [37].

Population Density:  Normal population densities in Canada range from
one to seven deer mice per acre (1-25/ha) [5].  Dalquest [28] estimated
an average deer mouse population density of 400 per acre (0.04 ha) in
thickly forested ravines in western Washington.


COVER REQUIREMENTS : 
Deer mice are often active in open habitat; most subspecies do not
develop hidden runways the way many voles (Microtus and Clethrionomys
spp.) do [3,125].  In open habitat within forests deer mice have a
tendency to visit the nearest timber [43].  In central Ontario deer mice
used downed wood for runways [85].

Deer mice nest in burrows dug in the ground or construct nests in raised
areas such as brush piles, logs, rocks, stumps, under bark, and in
hollows in trees [79,85,127].  Nests are also constructed in various
structures and artifacts including old boards and abandoned vehicles.
Nests have been found up to 79 feet (24 m) above the ground in
Douglas-fir trees [79].


FOOD HABITS : 
Deer mice are omnivorous; the main dietary items usually include
arthropods and seeds.  Deer mice also consume nuts, berries and other
small fruits, and fungi.  The prairie deer mouse prefers seeds of
foxtail (Alopecurus spp.) and wheat (Triticum aestivum), caterpillars,
and corn (Zea mays) where available [127].  In southeastern Montana deer
mice in big sagebrush/grasslands consumed arthropods and seeds; the
proportion changed with the year of study [107].

In Colorado pinyon-juniper woodlands 77 percent of the deer mouse diet
was pinyon seeds when the seeds were available.  True pinyon (Pinus
edulis) seeds were preferred over Mexican pinyon (P. cembroides) seeds
[36].  In the Pacific Northwest deer mice consumed over 200 Douglas-fir
seeds each in one night [41].  In southeastern Idaho crested wheatgrass
seeds are important in deer mouse diets when available; when they are
not available caterpillars are the most important item.  Availability of
seeds and caterpillars varies seasonally [67].  In northern Sierra
Nevada brushfields, deer mice consumed the largest proportion of seeds
in January, the largest proportion of fruits in October and November,
the largest proportion of arthropods in April, June, and July, and the
largest proportion of leaves (though never more than 20 percent by
volume) in April [61].  Kelrick and MacMahon [65] reported that antelope
bitterbrush seed was the most nutritious seed available in sagebrush
steppe, and big sagebrush seed the least nutritious.  Deer mice
exhibited a preference for antelope bitterbrush seeds (in penned feeding
trials) even if the deer mice had been trapped in other vegetative
communities [33].

Deer mice cache food in hollow logs or other protected areas [127].  A
single mouse may cache up to 3.2 quarts (3 L) of food for winter use [85].


PREDATORS : 
Deer mice are important prey for snakes (Viperidae), owls (Strigidae),
mink (Mustela vison), marten (Martes americana) and other weasels
(Mustelidae), skunks (Mephites and Spilogale spp.), bobcat (Lynx rufus),
domestic cat (Felis cattus), coyote (Canis latrans), foxes (Vulpes and
Urocyon spp.), and ringtail (Bassariscus astutus) [79].


MANAGEMENT CONSIDERATIONS : 
Some deer mouse subspecies have undergone range extensions at the
expense of other subspecies due to habitat alteration [3].  Lehmkuhl
and Ruggiero [73] listed the forest deer mouse at risk of local extinction
with increasing amounts of forest fragmentation.

Impact on Vegetation:  Peromyscus species rarely alter vegetative cover
since they do not eat leaves, twigs, or stems to any great extent.  Seed
predation may reduce establishment rate of preferred plant species [3].

Economic Impact:  Hooven [58] summarized a number of publications on
seed predation by deer mice.  He concluded that deer mice are capable of
causing substantial loss of tree seed crops.  Deer mice are probably the
major seed predator of Douglas-fir [79,84].  Some seedlings establish
from rodent seed caches, but they are usually in small groups and often
subject to disease and/or intense competition [84].  Numerous studies on
rodent control methods and their effectiveness have been published [79].
Rodenticides often temporarily reduce deer mouse populations, but rarely
effect complete population kill.  For example, Hoffer and others [56]
reported that rodenticide reduced Peromyscus species to "target levels"
in redwood (Sequoia sempervirens) stands, but the treatment left
survivors.  Deer mouse migration into depopulated areas is rapid; even a
small number of mice can quickly repopulate a treated area, rendering
control efforts futile.  In British Columbia removal of deer mice only
slightly increased the amount of surviving tree seed in both forested
areas and clearcuts [116].

Economic Benefit:  Deer mice are important in the diets of many
economically important furbearers, as well as that of other wildlife
[79].  Deer mice consume insects that cause damage to crop trees.  In
northern Ontario, deer mice and shrews (Sorcidae) consumed 13 percent of
the white pine weevils in a jack pine (Pinus banksiana) plantation [8].


REFERENCES : 
NO-ENTRY

Related categories for Wildlife Species: Peromyscus maniculatus | Deer Mouse