THE BIRDS 



American Eared Grebe. Colymbus nigricollis calif omicus (Heermami) 



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. Eeported 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. 



[247] 



