Sylvilagus
nuttallii
(Mountain Cottontail)
Description:
This cottontail is grayish
brown with a slight yellowish appearance above and whitish below. A diagnostic
characteristic is a narrow, black line along the margin of the ear. They have
a fairly large tail that is dark above and white underneath. Their total length
is 13.5 to 16.6 inches (338-415 mm), tail length is 1.2 to 2.2 inches (30-54
mm), and they weigh 1.4 to 1.9 pounds (630-870 grams).
Range:
From
eastern slopes of Cascade-Sierra Nevada ranges, east to western North Dakota
and Black Hills, and from southern Canada south to Arizona and New Mexico.
Habitat:
Prefers brushy, rocky areas in dense
sagebrush, and streamside thickets and forest edges. May sometimes climb into
junipers. In southeastern Idaho, prefers areas with relatively greater amounts
of forbs
. They are prevalent in
rock hills and canyons and may even be found in conifer forests.
Diet:
Feeds on grasses and other
herbaceous and woody vegetation, including sagebrush and juniper. In Idaho,
diet includes sagebrush, rabbitbrush, grasses, brush, bark, shoots, buds, and
crops.
Ecology:
May be active any time of day or night,
but is primarily crepuscular. Active throughout year. Uses burrows and forms.
Usually feeds in or near cover. The mountain cottontail is more solitary than
other cottontails. In some areas, gopher snakes and western rattlesnakes are
important predators on juveniles. In Oregon study, population density ranged from 19-254/100
ha; in southern British Columbia study, density in sagebrush was 23-43/100 ha.
In Idaho, species is known to carry tularemia.
Reproduction:
Breeds in late winter, spring, and
summer. Gestation
lasts 28-30 days. Females
may produce 4-5 litters of 4-5 young/yr. Females construct small, fur-lined
nests, and their young are capable of moving about independently in 4 to 5 weeks.
Conservation:
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Global Rank: | G5 |
State Rank: | S5 |
Important State References:
Johnson, M.K. and R.M. Hansen. 1979.
Foods of cottontails and woodrats in south-central Idaho. J. Mammal. 60:213-215.