164 GAME BIEBS OF CALIFORNIA 



Ring-necked Duck 



Marila collaris (Donovan) 



Otheb names — Eing-bill; Blaek-jaek, part; Blaek-head; Aythya collaris; Fulix 

 collaris; Fuligula collaris. 



Descbiption — Adult male: Whole of head, neck, breast and upper surface 

 black, except for a triangular patch of pure white on the chin and a more or 

 less distinct half-collar of chestnut brown around fore part of lower neck; 

 sides of head faintly glossed with violet; low crest on head shiny black with 

 faint greenish iridescence; iris yellow; bill lead color, with a narrow basal and 

 broad subterminal band of bluish white, the end black; outer surface of closed 

 wing and flight feathers slaty brown; speculum pearl gray, bordered above by 

 blackish feathers with slight greenish reflections, and behind by a narrow 

 margin of white; axillars and most of lining of wing pure white; tail slate 

 brown; sides and flanks white, delicately undulated with dusky; under surface, 

 including crescent-shaped extension upwards on each side in front of wing, 

 satiny white changing behind through an undulated area like the sides and flanks to 

 the black of the under tail coverts; legs and feet "greyish-blue," webs 

 "brownish-black" (Audubon, 1843, VI, p. 323). Total length 17.20-17.37 inches 

 (437-441 mm.) (two specimens); folded wing 7.75-8.15 (197-207); bill along 

 culmen 1.75-1.86 (44.4r-47.2); tarsus 1.36-1.42 (34.5-36.0) (six specimens). 

 Adult female: Top of head dark brown; sides of head lighter brown more or 

 less mottled with whitish; an area at base of bill, chin, and throat dull white; 

 bill usually, showing evidence of a light cross-bar; hind neck and whole of 

 back dark reddish brown shading into the black of rump; outer surface of 

 closed wing exactly as in male; breast, sides and flanks reddish brown, each 

 feather edged with lighter brown giving a somewhat mottled appearance; 

 lower surface otherwise white, shading into brown on the • lower belly and 

 under tail coverts; longest under tail coverts whitish. Total length 16.75 inches 

 (425 mm.) (two specimens); folded wing 7.26-7.62 (184^193); bill along 

 culmen 1.73-1.90 (43.8-48.2); tarsus 1.27-1.40 (32.3-35.6) (eight specimens); 

 all from California. Juvenile plumage: Male: Similar to that of adult female 

 (authors). Natal plumage: Forehead straw yellow; top and back of head and 

 most of upper surface of body, warm brown; sides of head and neck, and 

 throat, straw yellow, palest below; chin yellowish white; iris hazel; bill lead- 

 colored above, flesh-colored below; short narrow streak in middle of back 

 and large patches on sides of back and rump, pale straw yellow; under surface 

 of body, pale straw yellow, darkening on flanks and lower belly where some 

 grayish brown down shows through; feet lead colored, toes tinged with 

 yellowish. 



Marks fob field identification — Resembles Lesser Scaup but speculum 

 bluish gray instead of white. Back of male black instead of whitish, and white 

 of under surface extending upwards on each side to form a crescent-shaped mark 

 in front of wing. At close range the combination of narrower dark bill with 

 light cross-band near end, the light (chestnut) collar, and triangular white spot 

 on chin is diagnostic. Female has white around base of bill less sharply defined 

 than in Lesser Scaup, chin and throat continuously whitish, but lower surface 

 of body darker, and speculum bluish gray instead of white. Female Ring-neck 

 distinguished from female Redhead by smaller size, shorter wing, narrower bill, 

 whiter throat, and darker back. 



Voice— Said to resemble that of Greater Scaup Duck. 



