AMERICAN EARED GREBE. Colymbus nigricollis californicus (Heermann)

Field characters.—Size about that of teal duck; total length about 12 inches; body plump, neck and bill slender; tail so short as to appear to be lacking altogether. Upper surface of body brownish black; lower surface chiefly glistening white; a white patch on wing, shown in flight; in summer, head and chest slate, with yellowish brown streak on side of head; sides of body chestnut. Seen mostly in scattered flocks on lakes; sits low in water with neck straight up and head and bill horizontal; dives below surface at but slight provocation.

Occurrence.—Common on Mono Lake during the summer and autumn months; seen on Gem Lake, September 13, 1915. Reported on Mirror Lake in Yosemite Valley, August 21, 1917 (Mailliard, 1918, pp. 16, 18).

Mono Lake, in spite of its strongly alkaline waters, contains an abundance of animal life consisting chiefly of brine-shrimps and the larvae of a kind of fly. Since many different kinds of water birds are able to subsist, for a time at least, on this kind of food, many migrants stop here to rest and to feed, on their way to or from the north.

One of the commonest of these transient species is the American Eared Grebe. This bird spends practically all of its time on or in the water. Its thick, silky-textured plumage is well adapted for this aquatic mode of life. It is wonderfully expert as a diver and ordinarily seeks safety by diving below the surface of the water rather than by flight, being commonly reputed to "dive at the flash of the gun."

In late May, 1916, fully 150 Eared Grebes were to be seen on Mono Lake in the vicinity of the mouth of Leevining Creek. The birds were associated in pairs, and there was much chasing about and uttering of the shrill courting notes, but there was no evidence to show that they were actually nesting. Since the shores of the lake do not afford the type of surroundings required by these birds during the nesting season, it is probable that they were non-breeders, tempted to remain there by the abundant supply of food. Most of the birds seen at this time were molting, and one individual had entirely lost the power of flight; all its old primary wing feathers had dropped out almost simultaneously and the new ones were not yet fully grown.