262 NYROCA MARILA 



Stomachs of Scaups feeding both in fresh and in salt water, shot by myself on a 

 pond on Martha's Vineyard, November, 1919, and examined by Mr. Kubichek of 

 the U.S. Biological Survey, showed a great deal of vegetable matter, mostly Potamo- 

 geton pectinatus, with a trace of Chara, bivalves, mostly common blue mussels (My- 

 tilus edulis) with gastropods, Littorina, Odostomia and Nassa. O. W. Knight (1908) 

 mentions stomachs from Maine which, besides the usual food, contained "millions 

 of small crustaceans of the surface-swimming varieties." Mr. O. Bangs tells me that 

 on the west coast of Florida at Sanibel Isle he watched some Greater Scaups feeding 

 on the beach, running up and down between waves and picking up the large sand- 

 bugs (Hippa) that abounded there. This seems a very unusual feeding habit for any 

 diving duck. 



One taken at San Diego, California, contained 450 seeds of widgeon-grass, Ruppia 

 maritima (Grinnell, Bryant and Storer, 1918). 



European food appears to be precisely the same, judging from stomach analyses 

 quoted by W. Thompson (1851), Naumann (1896-1905), Seebohm (1885), Cor- 

 deaux (1896), Lilford (1895), Slater (1901) and Fatio (1904). In the summer they 

 eat great quantities of insects, a few young trout, small fresh-water snails and water- 

 plants (Millais, 1913). 



When Scaup are feeding on large mollusks, as they often do with us in late winter 

 and early spring, I have watched them at very short ranges and found that nearly all 

 of them came to the surface with the shell-fish in the bill; after rising, the morsel 

 which is held midway of the mandibles, not between the tips, would be readjusted 

 by a rapid motion and then very quickly swallowed. A few sips of water were taken 

 at the same time. 



Courtship and Nesting. As a rule, during migration or among wintering birds 

 which remain on our shores till April, very little pairing seems to have taken place. 

 I have never seen any signs of courtship in large flocks I have watched up to the 

 middle of the month, but Dr. C. W. Townsend tells me that he once in April saw 

 among a group which consisted of one-third males and two-thirds females, evidences 

 of display activity on the part of the males. Ther.e is no doubt that these and other 

 diving ducks pair much later than the surface-feeders, at any rate, there is always a 

 large proportion of non-mating birds among them. Furthermore it seems likely that 

 these birds do not permanently pair till they have arrived on or near the breeding 

 grounds. 



The display of the male is neither graceful nor spectacular. Two early writers 

 (Montagu, 1813; Faber, 1822) mentioned the essentials of it, namely, the cooing 

 voice and the peculiar head-toss accompanied by the opening of the bill. It has also 

 been well described by Cordeaux (1896) and by Millais (1913). Among my own 

 specimens in confinement I have observed it about the middle of May, though never 



