G RE ATER SCAUP 



251 



very low in tone, and the spectator must be within a few yards of the 

 birds to hear them." 



In North America the best-known breeding grounds of this Scaup 

 are in Alaska. The nest is usually placed not far from water and con- 

 sists of a depression in the ground, lined with grasses and down. From 

 5 to 22 eggs have been found in the nests but the larger number were 

 probably the product of more than one female as the usual number 

 seems to be from 7 to 10. The colour of the eggs is olive buff or deep 

 olive buff, about the same as that of the eggs of the Lesser Scaup and 

 the Ring-neck. The average size is 2.46 by 1.72 inches. The period of 

 incubation is probably from 25 to 28 days and is performed by the fe- 

 male alone. As soon as incubation commences the males gather by them- 

 selves and proceed to moult into the eclipse plumage. 



The diet of the Greater Scaup appears to be about one-half vegetable 

 and one-half animal food. The Diving Ducks may be classed as either 

 predominantly vegetable or predominantly animal feeders and the 

 Greater Scaup, therefore, comes on the border line between the two cate- 

 gories. It is preceded by the Lesser Scaup, whose food is 60 per cent 

 vegetable, and followed by the American Golden-eye, which consumes 

 only 26 per cent plant food, which amount, low as it is, is higher than 

 that of any of the remaining members of the Diving Duck group. Of the 

 752 birds whose stomach analysis showed the division of food to be as 

 stated below, nearly half had fed exclusively on animal food and about 



one-quarter exclusively on 

 plant food. It is interesting 

 to note that one in every 

 eight had made its entire 

 meal on one item of plant 

 food only, and one in every 

 seventeen on one single ani- 

 mal species. The examina- 

 tion showed the average diet 

 to be in the following ap- 

 proximate percentages: pond- 

 weeds, 19; muskgrass, 5; 

 water milfoils, 5; sedges, 3; 

 wild rice and other grasses, 

 3; wild celery, 2; miscellane- 

 ous plant food, 10; total vege- 

 table food, 47 per cent. Mol- 

 luscs (including oysters, 10), 

 39; insects, 7; crustaceans 

 and miscellaneous, 7; total 

 animal food, 53 per cent. 

 Since as many as 310 of the 

 stomachs analyzed came from 

 Oyster Bay, Washington, and 



