LESSER SCAUP DUCK 281 



water-plants. They sometimes feed in very shallow water merely by immersing the 

 head (Wetmore, MS.). 



In summer, stomachs collected at the Athabasca delta were found to contain from 

 55 to 99 % animal matter. This consisted chiefly of the larva? of midges (Chirono- 

 midae), water-boatmen (Corixidw), caddis larvae (Trichoptera) and dragon-fly 

 larvae. There were moderate amounts of the seeds of bur-reeds (Sparganium rnidti- 

 pedunculatum) , milfoil (MyriopkyUum spicatum) and rushes (Scirpus). 



Downy young collected by Mr. Francis Harper on Lake Athabasca, in 1920, con- 

 tained from 97 to 98% animal matter. The preponderant items were diving water- 

 beetles {Dytiscidce), larvae of dragon-flies, water-mites and water-striders. A few 

 seeds of bur-reeds and sedges (Carex) were also intermixed. 



In an interesting note Dr. Wetmore (1917a) states that on the Bear River 

 marshes, Utah, these birds in October were found crammed with brine shrimp 

 (Artemia) and the larvae of alkali flies (Ephydra). 



The Lesser Scaup sometimes feeds in sandy-bottomed waters which seem almost 

 devoid of food. Why they should remain in these places where they lose flesh and 

 become little more than living skeletons, is difficult to explain. During a freeze in 

 Florida which killed great numbers of small fish in the Banana River, Cory (1895) 

 found several of these ducks dead, evidently choked by fishes which they had at- 

 tempted to swallow. 



Courtship and Nesting. The Little Scaup pairs rather late in the spring like 

 many others of the group and those who have seen them at this time say that there 

 is nothing very active or striking in the behavior of the males. The display seems 

 to be exactly as it is in the Greater Scaup. Wetmore (1920) at Lake Burford, New 

 Mexico, and F. Harper (MS.) at the Athabasca delta have made detailed studies of 

 it. On May 5, 1920, the first of these ducks were seen on the Athabasca, males pre- 

 ponderating, but there was scarcely any evidence of display. By May 1 1 they were 

 very abundant, mostly in pairs, but still there was no courtship. During the next 

 few days, however, the males were seen opening and jerking the bill upward, with 

 no audible sound, or drawing the head down close upon the chest with the crown 

 feathers greatly depressed, giving the head a curious flattened appearance. A little 

 later pursuit flights were observed (June 17) and on June 9 the first nest was foimd. 

 As a matter of fact both Wetmore and Harper have shown that the female takes a 

 very active part in the display, swimming about with extended neck and head, jerk- 

 ing up her bill and uttering her scaup-scaup call. The birds during courtship are 

 constantly diving, the female appearing to elude or entice the males who sometimes 

 lose her when she comes up in a concealed spot. Pairs stay very closely together on 

 the water, often touching, and rival males make frequent drives at each other with 

 open bills. The only note which the male utters is a very low "coo" or whistle. 



