THE MAMMALS
SACRAMENTO COTTONTAIL. Sylvilagus audubonii audubonii
(Baird)
WASHINGTON COTTONTAIL. Sylvilagus nuttallii nuttallii
(Bachman)17
Field characters.Size
smaller than in either common domestic rabbit or jack rabbit; tail
cottony white on whole under surface; ears moderate, about length of
head (fig. 35b). Head and body 12-1/4 to 13-3/4 inches (310-348
mm.), tail about 2 inches (40-55 mm.), hind foot 3-1/4 to 3-3/4 inches
(81-94 mm.), ear (from crown of bead) 2-2/3 to 3-1/2 inches (68-90 mm.);
weight about 2 pounds or slightly over (1 kilogram). [Measurements from
audubonii.] Coloration above yellowish brown with moderate amount
of blackish overwash; whole under surface of body, tops of hind feet,
and under side of tail, pure white. Droppings: Flattened spheres
about 1/4 inch in diameter; scattered on ground where the rabbits
feed.
Occurrence.Common
resident in Lower Sonoran and part of Upper Sonoran Zone on west side of
Yosemite region. Recorded at Snelling, Lagrange, and Pleasant Valley
(S. audubonii); also east of Sierra Nevada in neighborhood of
Mono Lake (S. nuttallii). See footnote for details. Inhabits
brushy situations interspersed with clearings. Active in morning and
late afternoon.
17Two distinct species of
Cottontail Rabbit are found at the opposite ends of the Yosemite
section. Their habits are not known to differ to any great extent save
perhaps in adaptation to the different types of country in which they
live. Because of the lack of knowledge as to many of the details of
their life histories, they are here considered together.
SACRAMENTO COTTONTAIL, Sylvilagus
audubonii audubonii (Baird). The species which inhabits
north-central California, and reaches its southern limit in the vicinity
of the Yosemite section. It is common near Snelling and Lagrange, and a
few were noted in the hills near Pleasant Valley.
WASHINGTON COTTONTAIL, Sylvilagus
nuttallii nuttallii (Bachmnan). A Great Basin species. Occurs at
localities on the east side of the Sierra Nevada in the neighborhood of
Mono Lake (noted by us on Rush Creek, on Williams Butte, and near Mono
Lake Post Office). It may be distinguished from the west-side species by
grayer tone of coloration, especially on sides of body, and greater
amount of rufous on back.
Cottontail rabbits are present along the western and
eastern bases of the Sierra Nevada, but they do not invade the adjacent
hill country to any extent. On the west slope, the range of the
cottontail is nearly complementary to that of the brush rabbit, though
the two are not necessarily mutually exclusive. Cottontails are much
different in their habits from jack rabbits (which are hares, and not
true rabbits), and so these two types can and do occur in the same
general localities without competing seriously with one another.
The cottontail is nearly twice the weight of a brush
rabbit but only about one-third that of a jack rabbit. In general, it
resembles the former, possessing rather short legs and feet, and ears of
moderate length (fig. 35b). The cottony white of the tail, which
has given rise to the common name, is much more conspicuous in this
species than in the brush rabbit. The cottontail is essentially an
inhabitant of thickets, although it does not require such dense cover as
does the brush rabbit and it forages farther out into the open than does
that species. The growths which line the banks of the Merced and
Tuolumne rivers on their courses through the San Joaquin Valley afford
ideal conditions for cottontails; there they are numerous. But
cottontails do not always live about shrubbery. On some of the open
hillsides between Lagrange and Merced Falls, cottontails occur in
numbers, their only shelter being burrows in the ground, presumably
those deserted by ground squirrels and remodelled by the rabbits.
Cottontails are abroad chiefly in the early morning
and late afternoon hours; the duration of these daily periods of
activity is somewhat longer than that of the brush rabbits. At Snelling,
in May, they were seen abroad between 6 and 8 A.M. and were probably out
much earlier in the morning. Near Hayward (on the road to Coulterville)
a cottontail was seen to cross the road about 9 A.M. one day in early
May. In the afternoon, during the summer months, these animals may be
abroad as early as 4 o'clock, in places shaded from direct sunshine,
but at that season more are apt to be seen toward dusk of evening. In
favorable places two or three, and on occasion even more, of the animals
forage in close proximity to one another.
The cottontail seems to prefer thickets interspersed
with small clearings or grassy glades in which it may feed. In one case
three individuals were noted in an alfalfa patch in the river bottomland
at Snelling. They were about 25 feet out from thickets of willows and
blackberries, and each individual, though feeding, was actively alert
and ready to dash back to cover at the first intimation of danger.
Like all of the rabbit tribe the cottontail is speedy
when running, though for safety it depends on seeking shelter quickly
rather than on outdistancing its enemy. Rarely is there a chance to
judge even roughly of the speed at which a cottontail can run. Once, on
December 20, 1914, one was seen as it ran for a short distance parallel
to the railroad train near Merced Falls. The speed of the train was
estimated to be 20 miles an hour and the rabbit appeared to be going
about three-fourths as fast or about 15 miles an hour.
Concerning the breeding of the cottontail, little of
a definite character is known. On May 24, 1915, a half-grown individual
(S. audubonii) was captured at Pleasant Valley. This would point
to breeding early in the year. A young Washington Cottontail was seen
near Mono Lake Post Office on June 30, 1916.
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