ZZo Wetmore, Birds of Lake Burford, N. Mex. [April 



true of the "deep water" than of the "shallow water" ducks). 

 These breeding birds however after a little experience may be told 

 readily by their actions and demeanor, and seldom need be con- 

 fused with those others whose duties of procreation are for this 

 season completed. The mated birds when found alone are not 

 far from the site of the nest, are more alert and watchful at the 

 approach of an intruder, and often call a warning to the female. 

 When flushed they may fly only a short distance and then drop 

 into the water again, and in any case usually circle around and 

 seem loth to leave the neighborhood. In contrast to this the sum- 

 mering drake nearly always seeks the company of others of similar 

 status, so that little bands of these birds, often containing several 

 species, may be found standing about on shore sleeping, preening 

 or feeding. In demeanor these birds are more sluggish and when 

 flushed usually fly off to some safe spot often a considerable dis- 

 tance away. Their entire manner and custom of life is wholly 

 different from that of the bird still in company with his mate. 



At Lake Burford these summering male ducks increased steadily 

 in numbers until the time of my departure. Certain points and 

 open beaches were favorite resorts with them, and there I was sure 

 to find little flocks of males alone, or in company with a few pairs 

 of mated birds. By the time when these birds must of necessity 

 lead a sequestered life because of their inability to fly through 

 the molt of their flight feathers, the two prime requisites of food 

 supply and shelter would be present, as cover on the waters of 

 the lake in the form of growths of the two species of Scirpus was 

 steadily increasing while the great masses of potamogetons 

 promised abundant food for them. 



The lateness of the breeding season among the waterfowl here 

 may be attributed perhaps to the slow development of a proper 

 food supply. Until the first of June food suitable for these birds 

 was far from common in the waters of the lake. A number of 

 Mallards, and a few Cinnamon Teal and Lesser Scaup Ducks that 

 I shot for examination for one reason or another were all thin and 

 poor, and had very little fatty tissue underlying the skin. A fe- 

 male Ruddy Duck was the only individual examined that was fat 

 in any degree. It is possible that this poor physical condition 

 might retard physiologically the sexual maturity of these birds 



