SIERRA NEVADA WOLVERINE. Gulo luscus luteus Elliot

Field characters.—Size and proportions of heavily built dog; body stout (pl. 23c), rather broad; legs short, feet big; tail quite short. Head and body 27-29 inches (682-742 mm.), tail about 10 inches (250-260 mm.), ear about 2 inches (50-55 mm.); weight 17 to 25 pounds (7.6-11.3 kg.). Coloration above, yellowish brown, dark on lower back; head (except crown), feet, under surface of body, and end of tail, blackish.

Occurrence.—Sparse resident of Hudsonian Zone along crest of Sierra Nevada. Recorded definitely in head of Lyell Cañon at altitudes of 10,100 and 11,000 feet, July 26 and 25, 1915. Probably inhabits sparse forest. Solitary.

The wolverine is a rare animal anywhere on the Sierra Nevada, and it dwells only in the highest parts of these mountains. In consequence there is but scant information concerning it locally and much of that is hearsay. Only one of the local trappers in the Yosemite section had anything to relate concerning the species and he merely reported one killed in the region prior to 1914. Inclusion of the species here is based upon the capture of two individuals at the upper end of Lyell Cañon, late in July of 1915, by Mr. Charles L. Camp of our party.

Our station at the head of Lyell Cañon was at 9800 feet, but trapping was carried on up to timber line toward Mount Lyell in an effort to obtain various desirable species. For nearly a week a certain setting of steel traps was visited daily and baited with marmot bodies and other similar material. These traps were placed on bare rocky ground at the side of a thicket of white-bark pines at timber line (11,000 feet) on a rocky ridge between the McClure and Lyell forks. The snow was 4 feet deep in places near by. On July 25, a female wolverine was captured in this setting, and the day following an adult male was taken in another 'set' not far off, at 10,100 feet.

The first individual was held securely in all three traps. Nevertheless, it struggled violently, and from time to time uttered grunting sounds. When the observer placed his gun within reach, the animal quickly and easily bit off a piece of the black walnut stock.

The second wolverine captured was held by one hind foot in a steel trap, but this did not hinder it from going through a variety of motions limited only by the length of the trap chain. It climbed readily into a nearby wind-distorted lodgepole pine about three feet in diameter, using the claws in holding on to the trunk. Several times while being watched the animal started to dig into the ground, throwing up the earth at a lively rate; it would then turn over on its back and wallow in the cool earth, putting its feet into the air while doing so. Twice the wolverine sat up on its haunches with the forefeet against its breast after the manner of a bear. When approached very closely it made a lunge at the aggressor, uttering hoarse growls somewhat like those of a badger, and wrinkled up its nose, exhibiting its blunt teeth. The iris of this wolverine looked black; but when the pupil was dilated, the aqueous humor of the eyeball made the eye look green at certain angles.

In several other places, as at Vogelsang Lake and Fletcher Lake, tracks were seen which, chiefly through a process of elimination, were ascribed to the wolverine. The only other large carnivore in the high mountains is the Mountain Coyote. But the wolverine's track is not dog-like; the sole pad on the forefoot is divided up into small units, whereas the sole pad of the coyote is a single unit. The badger, which also has a relatively large track, has an elongated triangular foot pad.