226 UNIVERSITY OF COLORADO STUDIES 



144. Aix sponsa — Wood Duck. 



Very rare. Mr. Cowie and Bert Werley took three near Boulder in 1904, our only 

 definite records. 



146. Marila americana — Redhead. 

 Common on plains in migration. 



147. Marila vallisneria — Canvasback. 

 On plains in migration, not common. 



[148. Marila marila — American Scaup Duck. 



Felger's specimen recorded by this writer is believed to have been taken just over the 

 county line.] 

 149. Marila affinis — Lesser Scaup Duck. 



Rare migrant reported by Felger as collected at Longmont by L. C. Fipps, October 

 25,1903. See remarks on No. 135. I have examined but one specimen from the county. 

 [150. Marila collaris — Ring-necked Duck. 



Eliminated because Rowland's record not definite enough and Felger's found to be 

 just over the county line.] 



151. Clangula clangula americana — American Goldeneye. 



Rare migrant on plains. Cowie says hunters get a few every year. One in Uni- 

 versity collection taken on Beasley Lake, February 17, 1908. 



152. Clangula islandica — Barrow Goldeneye. 



Summer resident or perhaps resident, passing well up into the mountains. Gale 

 found young birds on upper St. Vrain, July 19, 1886. 



153. Charitonetta albeola — Bufflehead. 

 Common on plains in migration. 



154. Harelda hyemalis — Old-Squaw. 



Rare migrant reported by Rowland. H. G. Smith records one taken by Judge Park 

 at Longmont in 1903. As Longmont is near the county line, the lake where this was taken 

 may be in Weld County. 

 [165. Oidemia deglandi — White-winged Scoter. 



Felger's specimen recorded by this writer was taken just over the line at Calkins 

 Lake, so it is eliminated.] 

 167. Erismatura jamaicensis — Ruddy Duck. 



Reported by Rowland and Cowie as frequent in migration. One taken by Felger at 

 Lyons, March 24, 1900. 

 [169. Chen hyperborea — Lesser Snow Goose. 



Record too uncertain to retain.] 

 [169a. Chen hyperborea nivalis — Greater Snow Goose. 



Record too uncertain to retain.] 

 172. Branta canadensis — Canada Goose. 



Common on plains in migration. Found nesting west of Niwot by Cooke in 1897. 

 180. Olor columbianus — Whistling Swan. 



Migrant, not common. Two in University Museum and three more were brought 

 in for identification by local hunters in spring of 1907. 



