244 Wetmore, Birds of Lake Burford, N. Mcx. [April 



until June 17, and then disappeared as she had been incubating steadily 

 for three or four days. The nest in this case was built entirely of dead 

 Scirpus stems and was deep and well protected. Fluffs of down adhered 

 to the tules all about it so that the site was easily located. 



Four single males were observed on June 6, and a flock of twelve was 

 seen on June 8. After this males unaccompanied by females were common. 

 Part were birds that had nested here and a part I believed came from else- 

 where. 



16. Marila valisineria (Wilson). Canvas-back.— There were three 

 pairs of Canvas-backs on the lake that from their actions seemed settled 

 for the summer, but I was unable to find their nests. During the first 

 two days of my stay a female frequented a small cove below the cabin act- 

 ing as though she was nesting in the rushes but as she was constantly dis- 

 turbed she finally left this part of the lake. On June 8, a female was seen 

 swimming low in the water away from the rushes but in this case also I 

 was unable to locate a nest. 



On one occasion a female swimming after a male, quacked like a 

 female Redhead but in a more subdued flattened tone. The males were 

 silent. On May 27 while watching birds from a shore blind a male Can- 

 vas-back came around a point within 40 feet of me. He saw me and eyed 

 me closely but did not seem at all afraid, and swam on past, at intervals 

 dipping the tip of his bill in the water. A few minutes later as I stood up 

 he rose and flew rather heavily, paddling with his feet for about 80 yards 

 before being able to clear the surface entirely. Three pairs of these birds 

 were flushed from a resting place on a rocky beach on June 15. 



17. Marila afflnis (Eyton). Lesser Scaup Duck. — There were ten 

 or twelve pairs of bluebills and a few unmated males on Lake Burford 

 during the entire time of my stay but none apparently were nesting. 

 On June 1, I found 25 males and 23 females on Hayden's Lake, a part 

 of them in pairs. These had evidently stopped here in migration as 

 they passed on at once and were not seen again. The summering birds 

 were found in the open bays and in the forenoon were often seen resting 

 and sleeping on shore at open points. Like the Redheads they swam out 

 to open water as soon as I came in sight even though I was a considerable 

 distance away. 



The birds were seen in display on several occasions and as in the case 

 of the Redheads the more active part in this fell to the lot of the female. 

 Parts of the mating actions were witnessed on a number of occasions while 

 on June 3 the complete display was seen. A pair rested in open water in 

 front of me when suddenly the female began to swim back and forth with 

 the head erect, frequently jerking the tip of her bill up while the male drew 

 his head in on his breast and lowered his crest, giving his crown a curious 

 flattened appearance. The female turned alternately toward and away 

 from the male, sometimes biting gently at him, while occasionally he re- 

 sponded by nipping at her with open mouth. At short intervals she dove 



