THE MAMMALS
YOSEMITE CONY. Ochotona schisticeps muiri Grinnell and
Storer
Field characters.Body
size near that of House Rat; body short, face region rounded, ears large
and round, eyes small; tall so short as to be not visible. (See pl.
38a). Head and body 6 to 7 inches (155-180 mm.), tail (vertebrae)
2/5 to 3/5 inch (10-16 mm.), hind foot 1-1/8 to 1-1/4 inches (28-32
mm.), ear (from crown) 7/8 to 1-1/8 inches (22-27 mm.); weight 4 to
5-1/2 ounces (112-159 grams). General coloration pale gray, with more or
less of a reddish cast, especially in summer. Voice: A
high-pitched, 'stony' check-ick, uttered once; at times, a more excited,
repeated, check-ick, check-ick, check-icky, which may be kept up for 10
to 15 seconds. Workings: Small piles and scattered bits of
grasses and other plants, cut green and cured as 'hay.'
Droppings: rabbit-like, flattened spheres 1/8 inch in diameter
deposited in groups on rocks; also stains of liquid excrement at or near
tops of peaked, or roof-shaped, rocks, with other higher, sheltering
rocks about.
Occurrence.Common
resident in Hudsonian Zone, extending down locally into upper part of
Canadian Zone and up into Arctic-Alpine. Recorded from Ten Lakes, Tenaya
Lake, and Washburn Lake eastward to Bloody Cañon and to Ellery
Lake. Lives in rock slides (pl. 36a). Chiefly diurnal.
The Yosemite Cony is an alpine species, found only in
the higher parts of the mountains above the fir belt, chiefly in the
zone occupied by the alpine hemlock, white-bark pine, Sierran heather,
and cassiope. Even within this narrow area it does not live everywhere,
but is restricted to a single type of habitat, that comprised in
moraines or taluses of broken granite. (See pl. 36a).
Altitudinally, the cony is found, in the Yosemite National Park, as low
as 7700 feet, for example, near Glen Aulin, on the Tuolumne River;
upward it ranges to about 12,000 feet, as on the slopes of Mount Dana
and on the very summit of Parsons Peak, 12,120 feet.
In one typical rock slide, at the head of Lyell
Cañon, our estimates indicated a population of at least one cony
for every 750 square yards. This would mean a population of about six to
an acre. The extent of one individual's range is limited, probably
rarely exceeding the boundaries of the particular rock slide in which
the animal has its headquarters. While a cony will go some distance
among rocks for food materials, it will not ordinarily venture more than
two or three yards beyond the limits of that kind of shelter.
The summer traveler in the mountains is first
apprised of the presence of conies by hearing one of the animals utter
its far-off-sounding 'bleat.' In fact, this call is such a valuable
introductory aid that the experienced field observer finds it the best
practicable means of locating the animals. Hence he waits in a suitable
locality and listens intently until one of them utters its note and then
seeks out and scrutinizes the small area whence the sound comes until
its maker is discerned. This call is a moderately loud two or
three-syllabled utterance, and it has a nasal intonation. The quality of
the note suggests the clinking together of two flakes of granite. It has
been variously rendered by our field observers. One writes it yink,
yink; another, ke-ack, ke-ack, or ke-ack, ke-ack,
ke-ick-y; and another e-ckack',, e-chack', chee-ick',
chee-ick', chee-ick'-y. Sometimes the call is uttered but once;
again it may be repeated for ten or fifteen seconds, at first rapidly,
then more slowly, as if the cony's breath were being gradually
exhausted. The animal accompanies its calls with certain movements which
seem essential to their production. The whole body is jerked violently
forward, as if considerable exertion were necessary to expel the air
from the lungs, and at the same time the ears are twitched upward, so
that in face view their outlines suddenly catch the observer's eye.
For several months of each year snow covers
everything within the range of the Yosemite Cony. The various species of
animals which dwell there meet the resulting food scarcity in a number
of different ways. Most of the birds emigrate, the deer and coyote
descend to lower altitudes, the marmot hibernates, the gopher constructs
tunnels through the snow so as to reach the vegetation enveloped in the
snow mantle, and the white-tailed jack rabbit turns white and develops
big 'snow-shoes' on its feet so that it can forage upon the plants that
stick above the surface of the snow. The cony has still another method
of meeting the situation.
During the late summer and early autumn the Yosemite
Cony is busy at all hours of the day gathering materials to serve as
food while it is imprisoned among the rocks beneath the snow. It cuts
and stores away grasses and sedges and other plants which grow in the
vicinity of its home. These are carried into the rock slides and stored
in a dry, well-drained, shady yet airy place, sheltered above from snow
and rain, and free from the danger of running water belowan ideal
hay barn from the standpoint of a farmer. This mode of treatment, as it
happens, preserves unfaded the natural colors of the plants, whose
fragrance is that of well-cured hay free from mold. One such 'hay-pile'
seen by the senior author on Warren Peak, Mono County, September 26,
1915, was situated under a huge flat rock and was composed of about a
bushel of material. Samples from a pile examined at 8300 feet altitude
on McClure Fork of Merced River, August 26, 1915, included twigs and
needles of lodgepole pine, sprigs of "ocean spray" (Holodiscus
discolor dumosa), two or more alpine species of sedge
(Carex), with their characteristically rough stems of triangular
cross-section, a grass (Poa), and an epilobium. The nearest sedge
was twenty-five feet downhill in a wet place, while the nearest bush of
Holodiscus was at least seventy-five feet up the steep adjacent
slope. Currant and red-elderberry bushes grew nearer than any of the
other plants named, but neither had been touched. Evidently the cony
exercises some selection in the choice of its food materials.
When foraging, the Yosemite Cony gets as large an
amount of cut greens as it can hold crosswise in its mouth and then
carries the bundle to the 'barn.' Often stems of considerable length are
transported in this manner, and as the animal moves about, the ends of
these stems trail along beside or behind him. Many of the pieces found
in the hay piles were over a foot in length. One piece of cut sedge
measured forty-five inches in length; but it had been folded several
times. Six adult-sized conies and one juvenile were trapped at a hay
pile near Vogelsang Lake, and it may be that hay piles are community or
at least family affairs.
When not foraging and not occupied beneath the
surface of the slide, a cony sits in some partly protected place, often
under or near a large overhanging rock. The post usually selected is the
crest of a backward-slanting rock on a steep slope where the animal can
enjoy a wide angle of view below and yet be in position, when danger
threatens, seemingly to tumble back into the shelter of the slide. These
perches, or observation posts (pl. 38b), are marked by
accumulations of droppings, each one of an oblately spherical shape like
that of a rabbit but much smaller, and by whitish stains due to the
accumulation and action of the liquid excrement on the granite. When
perching the animal sits hunched up, usually with its back higher than
its head. It may maintain this position without any change for several
minutes at a time. When a cony "comes to attention" on an observation
post the head is often raised, the nose wiggled, and the feet shuffled,
all suggestive of mannerisms of a rabbit; but the movements of the head
are much quicker. The hobbling gait reminds one somewhat of the hopping
of a brush-rabbit. The cony moves rapidly and with apparent ease almost
everywhere in a slide, even over very steep and smooth rock surfaces. We
have never seen one of these animals assume the erect posture which is
common to rabbits.
The Yosemite Cony occupies the same rock-slide home
with the Bushy-tailed Wood Rat and the Sierra Marmot, but we have
learned nothing to indicate that these two large rodents molest it in
any way. In the matter of enemies, there are only three carnivorous
animals which dwell in the same situation and which we have reason to
believe may prey upon the cony. These are the Sierra Pine Marten and the
Least and Mountain weasels. At Vogelsang Lake, before sunrise of August
31, 1915, two conies were heard 'bleating' vociferously and they were
seen to run excitedly here and there among the rocks. Investigation
showed the cause of the disturbance to be a Least Weasel. From the
commotion which these conies made, it was inferred that they had
recognized the weasel as an enemy; a general alarm was being sounded. It
is improbable that birds of prey, hawks and owls, levy much toll,
because of the protected situations in which the cony lives; and there
are no large snakes to search out and devour this animal, as would be
the case if it lived at lower altitudes.
Conies seem to be most active during the early
morning and evening hours; but they evince more or less activity at all
times of the day, and they have been heard bleating on moonlight nights.
They seem to enjoy coming out and running about among the rocks or
sitting on their observations posts just as the afternoon shadows have
begun to creep over the rock slides. Sometimes they will sit for
considerable periods of time in perfect quietness, and the observer must
do likewise if he expects to catch sight of them.
The young of the Yosemite Cony are brought forth
during the warmer months of the year, and, as is the case with some of
the rabbits, the breeding season is an extended one. Thus, a
young-of-the-year, already nearly the size of adults, was taken on July
11, 1915, while as late as September 2 a female containing embryos was
found. Between July 3 and September 2, 1915, 4 pregnant females were
obtained; these held 3, 4, 3, and 4 embryos, respectively. The young are
precocious and venture abroad when only a third grown. Thus in a rock
slide near the Soda Springs on Tuolumne Meadows, an individual weighing
only 1-1/2 ounces (40 grams) was collected on July 12, and another even
smaller individual (weighing 35 grams) was taken on July 25, 1915. In
form the young resemble the adults closely save that, as with young of
many other mammals, the feet and head are disproportionately large.
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