HIGH SIERRA BAT. Myotis lucifugus altipetens H. W. Grinnell

Field characters.—Size medium (larger than Little California Bat, smaller than Large Brown Bat). (See pl. 21e.) Total length 3-1/2 inches (91-93 mm.); lower leg (tibia) well under 3/4 inch (15.3-16.4 mm.); hind foot 2/5 inch (10-11 mm.); ear 1/2 inch or over (13-15 mm.). Coloration light brown above, buffy beneath. Distinguished in hand by relatively large hind foot, more than half length of tibia.

Occurrence.—Inhabits Canadian and Hudsonian zones on Sierra Nevada. Altitudes, 7500 to 10,350 feet. Recorded at Merced Lake and Vogelsang Lake. Flies over and about tops of forest trees, and over lakes.

Bats inhabit the entire extent of the forested regions of the Sierra Nevada but each species occurring there occupies a definite part of this general range. The territory of the present species involves two high zones, the Canadian and Hudsonian. Vogelsang Lake, altitude 10,350 feet, where we obtained specimens, is next to the highest recorded station of occurrence for any bat in the United States.

Small bats, presumably of the present species, were observed occasionally about our camps at Tuolumne Meadows in July; but they came out so late that it did not prove possible to shoot specimens. But at Merced and Vogelsang lakes, in late August, three individuals were secured.

At Vogelsang Lake the bats were seen close over the water, but whether they came to drink or to capture the little insects seen 'spinning' on the surface of the lake could not be learned definitely. The continued skimming of the bats over the water suggested that they were actually gathering insects.

On August 19 and 30, 1915, pairs of bats were seen with one individual in rapid pursuit of another. In one instance the pursued individual was shot and was found to be a female. The actual mating of bats is believed, on fairly good evidence, to occur in the fall; but the young do not develop until spring. These pursuits may therefore have been of females by males. Between August 19 and September 6, in 1915, the High Sierra Bats made their first appearance from 6:58 to 7:10, on different evenings, the earliest appearance being on a quiet sultry evening.