Animal Life in the Yosemite
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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 below—an 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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Animal Life in the Yosemite
©1924, University of California Press
Museum of Vertebrate Zoology

grinnell/mammals70.htm — 19-Jan-2006