Vo1 ' 192^"] We™ore, Birds of Lake Burford, N. Mex. 239 



From their actions I believed that some of the females were laying on 

 May 29. A female that was just beginning to lay was taken on June 7, 

 and birds that had deposited several eggs were shot on June 8, 13, 14 and 

 15. One taken June 14, had the breast nearly denuded of down. A 

 mated female that was sterile was taken on June 15. While females were 

 at the nest the males remained from a hundred yards to a half mile away 

 standing on shore or swimming in the open water. These males were 

 alert and called instantly at the approach of danger. On one occasion I 

 shot a female for preservation as a specimen as she rose from the border of 

 the lake and her mate came over and swam up and down out of range for 

 several minutes calling anxiously. 



As early as May 29, drakes that had finished breeding were banding to- 

 gether and it would seem that they must have bred elsewhere. Follow- 

 ing that date these males were found daily, alone or in small flocks, and 

 their number was augmented steadily by others. They were usually 

 found resting or sleeping on shore in open places in company with drakes 

 of other species. A bird that was molting into eclipse was noted on June 

 4, and from then on birds in changing plumage were common. In this 

 molt they become dull in color first about the head and at the same time 

 lose the recurled upper tail coverts. A male almost entirely in eclipse 

 plumage was seen on June 18. 



On June 18, I saw a Mallard's egg that had been stolen apparently by 

 pack-rats (Neotoma) as it was found on a small island where there was no 

 other sign of predatory animals. The contents of this egg had been neatly 

 extracted through a hole at one end and the shell laid in a low growth of 

 Chrysothamnus with small flat bits of sandstone placed around and over it 

 nearly concealing it. It might seem that this was the work of boys save 

 that the egg was found on an island inaccessible save by boat, and the only 

 boat on the lake was in my possession. 



The female Mallards taken were nearly all molting the body plumage 

 and the new feathers that were coming in were very dark. These birds 

 differed from northern and eastern Mallards in the color of the bill also. 

 This was in general dull greenish slate with the base of the maxilla dull 

 orange while the tip of the bill often inclined to dull plumbeous. The 

 naked inter-ramal space was tinged with orange. In one or two there was 

 a dusky blotch on the culmen, but I examined none with the prominent 

 blackish spots on the orange at the base of the bill so prominent in females 

 of this species elsewhere. The toes and tarsi were dull orange. The bill 

 of these females in a way resembled that of the males but was duller in 

 color. 



(On May 25 a large very dark-colored duck in company with a mated 

 pair of Mallards passed me several times at close range. It had white 

 bars on either side of the speculum and was much darker in color than the 

 female Mallard, resembling a Black Duck markedly. It is possible that 

 this was a female mallard, but it seemed to have a clear olive green bill 



