SIERRA WHITE-TAILED JACK RABBIT. Lepus townsendii sierrae Merriam

Field characters.—Form that of Black-tailed Jack Rabbit, but size larger and general build heavier (fig. 34); feet heavily furred; tail large and fluffy. Head and body 19-1/4 to 20-1/2 inches (491-519 mm.), tail 3-1/2 inches (89-92 mm.), hind foot 6-1/3 inches (1601-164 mm.), ear from crown 6 inches (151 mm.). Body coloration (including ears) pale brown, ticked with black in summer, solidly pure white in winter; tail and feet wholly white at all seasons. Droppings: Flattened spheres about 1/2 inch in diameter.

Occurrence.—Resident in moderate numbers in high Sierras and at east base of mountains. Recorded from Tuolumne Meadows, and near Half Dome, eastward to vicinity of Mono Mills and slopes of Mono Craters. Ranges upward to 12,000 feet on higher peaks. Lives chiefly in open or sparsely wooded situations. Active mostly in late evening. Solitary.

The Sierra White-tailed Jack Rabbit is known to many persons as the "snowshoe rabbit'; occasionally it is called Sierra Hare. Like many of the other mammals and birds which occur along the crest of the Sierras this hare is a member of a northern group which finds conditions suitable for its existence in the boreal region of high altitude on the main Sierra mountain mass and at its colder east base. Locally, even in the midst of its range, this species is much less common than is the Black-tailed Jack Rabbit in the low plains country. For this reason among others exact information on many points in the life history of the Sierra Hare is still to be obtained.

The main range of the White-tailed Jack Rabbit begins at Tuolumne Meadows and Vogelsang Lake, where evidence of the species, in the way of droppings scattered on open ground, was found by us to be fairly abundant. An exceptional occurrence, reported by Mr. Lawrence Souvelewski, was that of a White-tailed Jack Rabbit at the immediate east base of Half Dome (altitude about 7500 feet). The animal was seen there on numerous occasions during the summer of 1919. On none of the western peaks (such as Mount Hoffmann, Mount Clark, or Clouds Rest) did we find evidence of the presence of this species; but along the main crest of the Sierras, rabbits were found to inhabit the gentler slopes of all the higher peaks such as Parsons Peak, Mount Florence, Mount Dana, and Warren Mountain, even up to altitudes of 12,000 feet. On the east slope, White-tailed Jack Rabbits were observed at Walker Lake, near Williams Butte, near Mono Mills, and on the slopes of Mono Craters.

When fully adult, this species is half again the size of its black-tailed relative. Compared with the latter its ears are slightly longer and proportionately broader, its head is more massive (fig. 34), its pelage denser and longer, and its tail longer and more fluffy in appearance; its feet are always heavily clad in fur (whence the name "snowshoe rabbit"). The white-tail has two regular molts each year. One in the fall changes the color of the animal from the pale brown summer coat to the pure white of winter. The second molt, in the spring, accomplishes a return to the brown pelage. The feet and tail do not participate in this color change but remain white all summer, save as discolored by contact with the ground. Sometimes certain areas on the body retain remnants of the brown coloration when the animal is in the white coat, and vice versa.

Fig. 34. Head of Sierra White-tailed Jack Rabbit, one-half natural size. Compare with fig. 33.

These big rabbits seem generally to keep to open places where they can see unobstructedly for long distances. Around Tuolumne Meadows, flat-topped hills bearing moderately open stands of trees together with some brush were often occupied. To this choice of habitat on the part of the rabbits, and to their crepuscular or nocturnal forage habits, we must attribute the general failure of interested persons to see more of them. Probably the rabbit sees the approaching person from afar and either makes off or else lies close in the shelter of rocks or bushes. In the few cases where a member of our party did catch sight of a rabbit it was usually from far off; the rabbit promptly went still farther away and was soon lost to sight. Near the Sierra Club camp of 1915 at the soda springs on Tuolumne Meadows one or two White-tailed Jack Rabbits were seen repeatedly by members of the Sierra Club and on a couple of occasions by some of our party. At this point the animals had evidently become somewhat accustomed to the presence of people.

On the Farrington ranch near Williams Butte one of our party stayed out for over an hour, from dusk until after dark, on the evening of September 21, 1915, watching for White-tailed Jack Rabbits in a wild hay meadow. One of the animals came into view at 6:35 P.M. It ran out from some tall grass and willow brush into a place where the grass had been cut, and there at some distance from the observer it sat bolt upright. Walking quietly, the observer attempted to approach, but the rabbit became frightened and started for another willow clump across the field. It did not appear to hurry, but its easy run carried it out of sight in an incredibly short time.

On another occasion, at Walker Lake, September 13, 1915, a White-tailed Jack Rabbit was come upon in a meadow. This was after 6 o'clock, in the late dusk of evening, and snow was gently falling. The rabbit, upon being frightened, loped away in easy fashion, and disappeared among the trees. We were told that in winters when the snow gets deep, the "snowshoes's" visit the haystacks of the Farrington ranch in numbers to feed. They are then ambushed by the Indians.

The young of the White-tailed Jack Rabbit are produced in the early spring months, to judge from the data at hand. A half-grown animal was seen at close range near Mono Mills on June 8, 1916, and another of about the same stage of growth was shot on the Farrington ranch near Williams Butte on June 25 the same year. The latter animal already weighed 3-3/4 pounds (1.7 kilograms).