Canvas-back 53 
at least equal to the middle toe without claw; it is straighter, and the 
forehead. does not rise up high behind it, while the nostrils. reach the 
middle of the bill; iris red, bill blackish throughout, feet greyish-blue. 
Length 22-0; wing 92:5; tail 27-5; culmen 2:4; tarsus 1-7. 
The female resembles the female Redhead, but can be distinguished 
by the back being barred with fine wavy white lines and by the longer 
and blackish bill. 
Distribution.—Breeding from Oregon and Minnesota northwards 
to Great Slave Lake and Alaska ; in winter eastwards to the Atlantic 
Coast from Delaware south through the southern and western states 
and Mexico to the City of Mexico. 
In Colorado the Canvas-back is somewhat less abundant than the 
Redhead, but it has been met with on migration over the greater part 
of the State, especially on the eastern side of the mountains. It 
arrives from the south early, only a little later than the Redhead. 
Loveland, February 10th to March 12th, are dates given by Cooke, 
and it has been noticed in El Paso co. (Aiken), at Orchard, March 26th 
(Warren), at Fort Lyon (Cooke), and in Boulder co. (Henderson) on 
the eastern plains; at Breckenridge (Carter), in the mountains and 
at Grand Junction, February 20th, by Sullivan (Rockwell). 
Felger reports that he found it nesting at Barr Lake on June 6th 
and July 4th, 1900, and this is confirmed by Hersey and Rockwell. 
Aiken saw a small flock of five on a lake near Limon, May 19th, 1899, 
which may have contemplated nesting, or were possible late migrants. 
Cooke believed that a few birds wintered on the plains of northern 
Colorado, and Felger confirms this. 
Habits—The great reputation of the Canvas-back 
is due to the fact that in its winter home on Chesapeake 
Bay it feeds almost entirely on the roots and bulbs of 
the so-called wild celery (Vallisneria) which grows very 
abundantly in that estuary; elsewhere it is no better 
than any other Duck ; in fact the flavour of all Ducks 
is entirely dependent on what they have been feeding on. 
The Canvas-back is generally found in large flocks 
on considerable sheets of water, and is a strong flyer 
and a wonderful diver ; when wounded it often escapes 
in this manner. Owing doubtless to constant persecution, 
it is exceedingly shy and wary. 
It resembles the Redhead in its nesting-habits, building 
very often in shallow water among thick rushes and 
