38 Birds of Colorado 
Mottled Duck. Anas fulvigula maculosa. 
A.O.U. Checklist no 134a—Colorado Records—Ridgway 73, pp. 177, 
188 (Anas obscura) ; Morrison 89, p. 148; Cooke 97, pp. 53, 156, 194; 
Felger 09, p. 280; 10, p. 451. 
Description.—Resembling « dark-coloured female Mallard; head 
and neck buffy, finely streaked with dusky ; chin and throat isabella- 
colour unmarked; under-parts mottled about equally with dusky 
and light brown; feathers of the breast and back with brown centres 
and margins; speculum greenish purple framed in black, the feathers 
narrowly tipped with white ; iris dark brown, bill greenish with a black 
spot at the base of the lower edge of the upper mandible ; legs reddish- 
orange. Wing 10-0; tarsus 1:75; culmen 2:25. 
The sexes are alike, except that the female has no black spot on the 
mandible, 
Distribution Breeding in Texas and probably north to Kansas 
and Colorado. 
A Duck identified formerly as the Dusky or Black Duck of the 
Atlantic coast, has been recorded on several occasions from Colorado. 
It was first noticed by Ridgway on the authority of Aiken. Thorne 
took it at Fort Lyon (Morrison) and Osburn on the Big Thompson 
near Loveland, March 15th, 1889. Cooke in his second supplement 
(p.194) considered that these Ducks should be referred to the present 
subspecies. 
In the Natural History Museum at Denver there is a Duck taken 
November 6th, 1907, near Loveland, by Mr. Blaney ; it is mounted, 
and the bill has been coloured so that it is impossible to make out the 
spot on the mandible, but the throat is clearly plain and unstreaked, 
and I have little doubt that it should be referred to this subspecies, 
which may therefore be considered a straggler to Colorado. Felger 
(09) gives several additional records from the neighbourhood of Denver, 
and in a recently published note (10) considers that Cooke is in error, 
and that these Colorado Ducks should be referred to A. rubripes. I 
have myself carefully examined the example mounted in Denver, 
and am inclined to support Cooke in his determination. 
Genus CHAULELASMUS. 
Closely resembling Anas, with a tail of sixteen feathers, but wing 
speculum white, and in the male the greater coverts black, the 
middle coverts chestnut. 
One nearly cosmopolitan species. 
Gadwall. Chaulelasmus streperus. 
A.O.U. Checklist no 135—Colorado Records—Allen 72, p. 159; 
Aiken 72, p. 210; Henshaw 75, p. 474; Drew 81, p. 142; 85, p. 18; 
