56 BIRDS OF COLORADO. 
149. Aythya affinis. Lesser Scaup Duck. 
Migratory; not common. Its range is much the same as 
the last species, but it is rather more common. Occasionally 
found in southern Colorado in winter. Reaches northern Colo- 
rado early in March. 
150. Aythya collaris. Ring-necked Duck. 
Migratory; rare. It is a little strange that this duck 
should be so uncommon as it seems to be in Colorado, since it 
is more common in Kansas than either of the others. Probably 
occurs on both sides of the range, though all the records are on 
the plains east of the foothills. Breeds far north. 
151. Ciangula clangula americana. American Golden-eye. 
Migratory; rare. Occurs throughout the State, but never 
common. Breeds far north, but begins to migrate early. 
C. E. Aiken took one in .southern Colorado at 9,000 feet on 
August 30, 1874. 
152. Clangula Islandica. Barrow’s Golden-eye. 
Resident; not common. The distribution of Barrow’s 
Golden-eye in Colorado is rather strange. It is a northern spe- 
cies, coming south in the winter to Colorado, and then when 
spring returns quite a share of these winter birds remain to 
breed in the mountains. So there results the queer condition 
of a northern species breeding in the mountains almost at the 
extreme southern limit of its range. On the plains it is a rare 
migrant and winter visitant; in the mountains it has been found 
breeding throughout the whole western half of Colorado, usually 
at about 8,000 feet. Chas. F. Morrison has the following note 
concerning its occurrence: “This species might almost be 
called a resident in southwe.stern Colorado. I can record its 
breeding in Dolores County, and have taken them all through 
the winter in the ponds below Fort Lewis.” (O. & O. XIII. 
1888, 165.) It nests in trees. There are no records of its ex- 
tending much east of the mountains far out on the plains, and 
it never has been taken in Kansas. 
153. Charitonetta albeola. Buffle-head. 
Migratory; common. Occurs throughout the State in 
migration, and is likely to be found near any open water in the 
winter. Breeds far north. 
154. Harelda hyemalis. Old-Souaw. 
Winter visitant ; rare. A northern species coming south 
into Colorado in the late fall and winter. The only records 
come from the north central part of the state where G. F. 
Breninger writes that he found a dead bird on the shore of one 
