BIOLOGICAL DATA AND HABITAT REQUIREMENTS
WILDLIFE SPECIES: Neotoma cinerea | Bushy-Tailed Woodrat 



TIMING OF MAJOR LIFE HISTORY EVENTS : 
Breeding season - Bushy-tailed woodrats breed from January to August.
In Canada, the peak of the breeding season is generally between March
and June [1].  In a laboratory study, bushy-tailed woodrats bred from
February to July [9]. 

Social organization - Bushy-tailed woodrats occur in small family
groups, which are often widely separated [3].  Males keep harems of one
to three females.  The males are territorial and aggressively defend
both dens and foraging areas [1].  Harems appearently begin to form in
groups of immigrating subadults during the year before breeding.  Young
males leave home areas by 2.5 months, but females remain home to breed
there the next year [9].

Gestation period and litter size - The gestation period is 27 to 32
days.  Litter size averages 3.5 young, but may vary from one to six
[1,8].  In the laboratory, females may have up to seven litters in 1
year, but under favorable conditions in the wild, two litters may be
produced during the same year about 2 months apart.  In the northern
part of their range, probably only one litter is produced each year.
Some females experience postpartum oestrus and breed within 24 to 48
hours after parturition, while others may not breed until after the
first litter is weaned [1].

Maturation of young - Young venture out of the nest at 22 days of age
and are weaned between 25 and 30 days [1,9].  Maturation time seems to
vary from one area to another.  In Colorado, Finley [11] considered
bushy-tailed woodrats mature at 4 months of age.  During a laboratory
study, Escherish [9] found that bushy-tailed woodrats mature between 5
and 10 months of age, and stated that bushy-tailed woodrats generally
can breed the spring or summer after birth.  According to Banfield [1],
bushy-tailed woodrats in Canada are capable of breeding at about 11
months old.  Clark and Stromberg [6] found that bushy-tailed woodrats in
Wyoming do not breed until they are 2 years old.  In a laboratory study,
Egoscue [8] found that females born in late spring or summer began
breeding later the following year and had fewer litters their first
breeding season than females born early in the year.

Dispersal - Dispersal of young may occur shortly after weaning or over
several years.  Dispersal distances of 1.4 to 2 miles (2.2-3.2 km) have
been recorded [3].  Since the distribution of family groups is patchy
and the families are generally well separated, dispersal of young is an
important component of metapopulation viability.  The ability to
recolonize vacated habitats is necessary.

Habits - Bushy-tailed woodrats are primarily nocturnal and are most
active during the half hour after sunset and at dawn, year-round
[1,9,30].

Longevity - Bushy-tailed woodrats may live to be 3 to 4 years of age
[22].


PREFERRED HABITAT : 
Bushy-tailed woodrats are found from sea level to mountaintops up to
14,110 feet (4,300 m) elevation.  They are associated primarily with
rocky environments in mountainous country, inhabiting cliffs, talus,
caves, river canyons, rocky streamsides, and rock outcrops [1,3,22].  In
southwestern Oregon, bushy-tailed woodrats generally occur in heavily
forested areas among rocks overgrown with vegetation.  Buildings, old
logs, and log piles suffice where rocks are scarce.  In the transition
zone between the Douglas-fir-western hemlock (Tsuga heterophylla) forest
and mixed conifer forest in southwestern Oregon, bushy-tailed woodrats
persist without rock outcrops or talus.  There, streamside forests
provide the best environment followed by closed sapling-pole stands of
mixed conifers and old growth [3].

Home range - Most bushy-tailed woodrats will forage up to 450 feet (137
m) from the den; this constitutes a 15-acre (6.1-ha) home range.  In
southwestern Oregon, Carey [3] recorded movements of up to 1,250 feet
(381 m) within trapping grids that were only 1,300 feet [396 m] wide,
which suggests a maximum home range of about 110 acres (44.5 ha). The
average maximum distance moved per individual was 280 feet (85.3 m).
The minimum habitat needed per family group has been estimated as 80
acres (32.4 ha) [3].  It is rare to find more than one family group on a
talus slope covering 2 to 5 acres (0.8-2.0 ha).  Banfield [1] reported
an average population density of one bushy-tailed woodrat to 20 acres
(8.1 ha) in Canada.

Dispersal corridors - Persistence of a bushy-tailed woodrat population
often depends on corridors that connect family groups.  Steamside zones
might play a key role in providing dispersal corridors.  Heavily
timbered streamsides are characterized by a diversity of plant species
and vertical diversity of vegetation that includes forbs, shrubs, and
deciduous trees.  These provide food and, together with the noise of the
stream, some protection from predation.  Mixed-conifer old growth may
also be used as a dispersal corridor [3].


COVER REQUIREMENTS : 
In most areas, adequate rock cover is the most important resource for
the bushy-tailed woodrat, especially in areas that have cold weather and
heavy snowfall.  In areas of mild climate, hollow trees, tree cavities,
and fallen trees provide adequate cover [9].

Shelters - Bushy-tailed woodrats often build shelters on or near the
ground [1,3,9,11].  Shelters are commonly found in rock crevices or
burrows under overhanging rocks.  Shelters may also be built in hollow
trees, hollow logs, log piles, and burrows under logs.  In the Oregon
Coast Range, bushy-tailed woodrats occasionally build arboreal shelters
up to 50 feet (15 m) above ground that are loosely constructed of sticks
[3].
 
Shelters consist of two parts:  the den (external structure) and the
nest (internal nest cup).  Bushy-tailed woodrats usually build a bulky
den of sticks, bones, foliage, debris, and human artifacts [1,3].  The
den serves as a defensive maze to ensure time to escape from a predator,
and also provides an eating platform and a food drying platform [1].
Within these dens bushy-tailed woodrats build small, open, cuplike
nests [3].        


FOOD HABITS : 
Bushy-tailed woodrats have a varied diet of woody plants, mushrooms,
berries, seeds, and herbage [3,9,22].  In fall, cuttings are gathered and
stored in crevices or dens for winter use [6,22].

In the Pacific Northwest, bushy-tailed woodrats eat the leaves and
cambium of Douglas-fir, Sitka spruce (Picea sitchensis), and western
hemlock, the leaves of western redcedar (Thuja plicata), and the green
parts of Pacific bleeding heart (Dicentra formosa), red elderberry
(Sambucus racemosa ssp. pubens), waterleaf (Hydrophyllum spp.), trailing
blackberry (Rubus ursinus), Himalaya blackberry (R. discolor), and many
other species [3].

In Canada, bushy-tailed woodrats show a preference for the leaves of
quaking aspen, cherry (Prunus spp.), rose (Rosa spp.), snowberry
(Symphoricarpos spp.), currants (Ribes spp.), elderberries (Sambucus
spp.), and willows (Salix spp.).  The twigs and needles of western white
pine (Pinus monticola), Douglas-fir, Engelmann spruce (Picea
engelmannii), subalpine fir (Abies lasiocarpa), and junipers (Juniperus
spp.), and the seeds and/or fruits of Douglas-fir, anemones (Anemone
spp.), fireweed (Epilobium angustifolium), gentians (Gentianella spp.),
honeysuckle (Lonicera spp.), cinquefoils (Potentilla spp.), gooseberries
(Ribes spp.), raspberries (Rubus spp.), and elderberries are also eaten
[1].

In the pinyon-juniper ecosystem of the Piceance basin of Colorado, woody
plants accounted for over 75 percent of the bushy-tailed woodrat's diet.
Bitterbrush (Purshia spp.) was the predominant food item.  Big sagebrush
(Artemisia tridentata) seemed to be avoided. Forbs were eaten, but
composed less than 15 percent of the diet [17].


PREDATORS : 
Bushy-tailed woodrats are prey for many predators including the spotted
owl (Strix occidentalis), great horned owl (Bubo virginianus), boreal
owl (Aegolius funereus), red-tailed hawk (Buteo jamaicensis), goshawk
(Accipiter gentilis) and other hawks, rattlesnakes (Crotalus spp.),
American marten (Martes americana), bobcat (Lynx rufus), weasels
(Mustela spp.), spotted skunk (Spilogale putorius), striped skunk
(Mephitis mephitis), wolverine (Gulo gulo), foxes (Vulpes spp. and
Urocyon spp.), coyote (Canis latrans), and wolf (Canis lupus)
[1,3,9,18,22].  Within spotted owl home ranges, especially near nest
groves, the rate of predation on bushy-tailed woodrats may be very high,
since bushy-tailed woodrats consistute a major portion of the spotted
owl prey base [3].



MANAGEMENT CONSIDERATIONS : 
NO-ENTRY


REFERENCES : 
NO-ENTRY

Related categories for Wildlife Species: Neotoma cinerea | Bushy-Tailed Woodrat