VoL 1920 XVI1 ] Wetmore, Birds of Lake Burford, N. Mex. 231 



from May 23 to June 5, were certainly on their way to the mouth 

 of Bear River, Utah, as that is the only breeding colony of these 

 birds in the interior in this general region. A flock of Franklin's 

 Gulls in full breeding plumage frequented the lake from June 14 to 

 16, and it may be that these were in passage to the same place as 

 the time of their departure coincided with the arrival of a part of 

 the breeding birds on Bear River; while apparently there is no 

 intermediate region where they may nest. It may be supposed 

 therefore that part of the ducks that come to Lake Burford in 

 the fall come down from the Salt Lake Valley and use this lake as a 

 resting place before passing on farther south. It is probable that 

 this lake is merely one point in a broad line of flight that covers 

 western New Mexico and the most of Arizona wherever water is 

 found. 



Annotated List of Birds 



1. Colymbus nigricollis calif ornicus (Heermann). Eared Grebe. 

 The Eared Grebe was the most abundant of the breeding marsh birds at 

 Lake Burford and while the species was common when work was first begun 

 at the lake it increased suddenly in abundance between May 30 and June 



1. Many of these Grebes were seen in pairs on my arrival, but until June 



2, small flocks containing unmated birds of both sexes were found in cer- 

 tain of the open bays. As the season advanced these birds showed more 

 activity, and after June 5, the Grebes were always found in pairs, that 

 rested on the water with male and female never separated far from one 

 another. Many were seen in the open water, some near shore and others 

 farther out, while other pairs frequented the shelter of the fringing tules. 

 All were tame and showed little fear so that when I remained quiet I had 

 no difficulty in watching them, often at a distance of only twenty or thirty 

 feet. They were without question the most interesting birds on the lake 

 and were continually revealing new habits and mannerisms so that the 

 watcher was certain to be repaid for any time spent in observing them. 

 The displays witnessed during their mating were perhaps of the greatest 

 interest. 



The most striking of these courtship displays was one similar to that 

 styled the "Penguin" attitude by Julian Huxley in his studies of similar 

 actions in the Great Crested Grebe of Europe. 1 I was fortunate in wit- 

 nessing this daily in whole or in part during my stay at Lake Burford. At 

 the beginning of this, one of the most characteristic acts in the courtship 

 of the Eared Grebe, the two birds, male and female, usually rested on the 

 water five or six feet apart. Suddenly the male assumed an attitude fac- 



'Proc. Zool. Soc. London, 1914, pp. 491-562, 2 plates. 



