ANATID^— THE SWANS, GEESE, AND DUCKS. 163 



Aythya affinis (Eyt.) 



LESSEE SCAUP DVCK, 



Popular synonyms. Little Blaok-head; Little Blue-bill; Biver Blue-biU; March Blue- 

 bill: Mud Blue-bill; Broad-bill; Creek Broad-bill (Long Island) ; pato boludo de 

 oabeza cafe (Mexico) ; Elver Shuffler. 



FuKgulamarildXVD.Orn.Biog.ilUlSS&.ZiS; v. 1839, 614, pi. 229; Synpp. 1839,286; B.Am. 



Vi, 1843, 316, pi. 397. 

 Fuligula affinis Etton, Mon. Anat. 1838. 157.— CouES, Key, 1872. 389; Check List, 1873, No. 

 501; 2d ed. 1882, No. 721; B. N. W. 1S?4, 573. 

 Fulix affinis Baied, B. N._Am. 1858. 791; Cat. N. Am. B. 1859, No. 589.— BiDaw. Orn. 40th 



Par. 1877, 626; Nom. N. Am. B. 1881, No. 615.— B. B. & R. Water B. N. Am. ii, 1884. 22. 

 Aythya affinis Stejn. Orn. Expl. Kamtsoh! 1885, 161.— A. O. U. Check List, 1886, No. 149.— 

 BiDGW. Man. N. Am. B. 1887, 103. 

 FuUgula minor BelIi, Proo. Acad. Nat. Sci. Phila. i, 1842, 141.— Qieaud. B. Long, i, 1844, 323. 



Has. The whole of North America, south to Guatemala and the West Indies; breeds 

 chiefly north of the United States. 



Sp. Chab. Similar to A. marito reeorcJico, but considerably smaller; adult male with 

 the head less glossy and the gloss usually purplish instead of green; flanks waved or zig- 

 zagged with blacldsh. Total length, about 15.00-17.00 inches; extent, 26.00-27.75; wing, 7.50- 

 8.25 (average 7.81); oulmen, 1.58-1.90 (1.75); greatest width of bill, .80-.95 (.89); least width of 

 bill .60-.78 (.69); tarsus, 1.15-1.50; middle toe, 2.00-2.25. 



In acJdition to the characters of coloration mentioned, above, 

 the lower part of, the neck is usually dull brownish and quite 

 lustreless, in many examples forming as distinct a collar 

 as in some specimens of F. colla/ris, though the color is never no 

 rufescent as in the latter species. 



The Little Black-head has much the same range and essen- 

 tially the same habits as its larger relative {A. mwrila neofl'ctica) , 

 though, as Dr. Brewer has truly said, it is extremely difficult, 

 if not at present quite impossible, to state just wherein the two 

 differ in these respects, in consequence of the confusion of their 

 history resulting from the great similarity of their appearance. 

 Dr. Brewer further states that so far as his Own observations 

 go, he is inclined to agree with Dr. Cooper in regarding the 

 present species as a much more decided frequenter of the land 

 than the other, and adds that "it is quite probable that much 

 that has been written by Audubon and others in regard to the 

 Scaup Duck, as seen on our rivers and lakes, may have had 

 reference only to this species." "A careful examination," says 

 he, "of Audubon's account of the habits of the Scaup Duck 

 clearly indicates tii at nearly all he says of it belongs in reality 

 to this species; and this supposition is strengthened by the fact 



