HOARY BAT. Nycteris cinerea (Peale and Beauvois)

Field characters.—Largest bat in the Yosemite region, slighly larger than either Large Brown Bat or Pallid Bat. Total length 5-1/2 inches (135 mm.), tail 2-1/2 inches (60 mm.), hind foot 2/5 inch (11 mm.), ear 1/3 inch (9 mm.), stretch 15-1/2 inches (398 mm.). Coloration 'hoary,' the hairs being brown at base and extensively tipped with white; wing membranes blackish. Tail membrane furred like back. (See pl. 21a.)

Occurrence.—Recorded definitely twice in Yosemite region; probably rather common. Individual specimens taken at Snelling, April 15, 1916, and at Merced Lake, August 20, 1915. Inhabits wooded localities and finds daytime refuge in trees. Solitary.

The Hoary Bat, one of the most distinctive of our Californian bats, is included in the fauna of the Yosemite region on the basis of two specimens captured. On several other occasions, however, individual bats which we believed to be of this species were seen in flight.

Compared even with the Large Brown Bat the present species stands out as of very large size. As additional characters, it has long and pointed wings and a swift and irregular flight. Usually it flies low among the trees but sometimes courses up 25 to 30 feet above the ground. It appears at about the same time in the evening as does the Large Brown Bat. One Hoary Bat was shot at 7:12 P.M., August 20, 1915, at Merced Lake.

The Hoary Bat is known to be a definitely migratory species. In winter it occupies the hills and valleys of California; in summer it goes to the higher mountains or to more northern latitudes. Its seasonal movements thus parallel those of some of our birds, the Audubon Warbler, for instance.

This bat is strictly solitary in its habits, and spends the day hanging amid the foliage of some tree. Its heavy coat of fur, which extends out onto the upper surface of the wings and clear over the tail membrane, is an evident adaptation to the relatively low temperature of its alpine and northern habitat, and to its solitary and open manner of 'roosting.'