150 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I50 



AYTHYA COLLARIS (Donovan): Ring-necked Duck; Pato de Collar 



Anas collaris Donovan, Brit Birds, vol. 6, 1809, pi. 147, and text. (Lincolnshire?, 

 England. Found in Leadenhall Market, London.) 



Size of lesser scaup duck but with gray wing speculum; a light 

 colored ring around bill back of tip ; male with dark back. 



Description. — Length 410 to 460 mm, Male, head and neck black 

 with a sheen of purple ; an indistinct chestnut collar on neck ; back 

 and upper breast black; lower breast and abdomen white; wing 

 speculum gray ; bill bluish gray, with two white rings and a black tip. 



Female, head, neck, and upper parts dull brown ; lower breast and 

 abdomen white ; speculum and light-ringed bill as in the male. 



Measurements. — Males (5 from southeastern United States), wing 

 185-199 (191.4), tail 54.8-57.0 (54.8) culmen 43.7-46.4 (45.0), tarsus 

 34.3-35.9 (34.9) mm. 



Females (5 from southeastern United States), wing 173-183 

 (178.8), tail 50.8-57.3 (54.0), culmen 42.2-46.7 (44.2), tarsus 32.1- 

 35.4 (33.6) mm. 



Winter visitor from the north. Not common. 



This is a migrant from North America, that was first formally 

 recorded for Panama from a male seen on a lake at the Rio Caimito 

 near Red Tank in the Canal Zone on February 25, 1951, by Dr. and 

 Mrs. Robert Scholes (Condor, 1954, p. 166), I saw several on the 

 Rio Chagres near Juan Mina in January and again in December 1955, 

 and noted one near Pedro Miguel on January 7, 1960. Karl Curtis 

 informs me that they have been shot from time to time along the 

 Rio La Jagua. 



The species, here near the southern limit of its winter migration, 

 is little known in Panama because of its general similarity to the 

 Lesser Scaup Duck. 



OXYURA DOMINICA (Linnaeus): IVIasked Duck; Pato Tigre 

 Figure 29 



A^uis dominica Linnaeus, Syst. Nat, ed. 12, vol. 1, 1766, p. 201. (Hispaniola.) 



A small, mottled-brown duck, with heavy neck, and tail usually 

 elevated when on the water; a prominent white patch in the wing. 



Description. — Length 320 to 360 mm. Male, head and throat black ; 

 neck, upper surface, and sides chestnut-brown, the two last men- 

 tioned streaked with black; wings and tail black, with a large white 

 patch on the wing coverts ; tmder surface dull brownish buff. 



Female, dull black above, spotted and barred irregularly with 

 brownish buff; sides of head and under surface buffy brown, with a 



