374 Birds of Colorado 
A genus of considerable size, containing at least thirteen species and 
wa number of additional subspecific and intermediate forms, ranging 
over North and Central America as far as Costa Rica, but breeding 
in the higher mountains of the boreal zone only to the southwards. 
Colorado has representatives of six species as well as three inter- 
mediate forms which are possibly hybrids. 
Key oF THE SprEciEs (for the intergrades, see p. 380). 
A. Plain grey or dusky grey on the head and back. 
a. Larger—wing 3-35—and paler; three outer tail-feathers white, 
a double white wing-bar. J. aikeni, p. 374. 
b. Smaller—wing 3-15—and duskier; third pair of outer tail- 
feathers largely dusky ; no wing-bars. J. hyemalis, p. 375. 
B. Back some shade of brown, contrasting with the head. 
a. Head, neck and chest black, contrasting with the sepia-brown 
back; flanks slightly vinaceous. J. shufeldti, ¢ p. 376. 
b. Head, neck and chest greyish, not contrasting very strongly 
with the greyish-brown back. 
a? Smaller; wing under 3-0; flanks slightly vinaceous. 
J. shufeldti, 2 p. 376. 
b? Larger; wing about 3-30; flanks strongly vinaceous- 
pink, extending almost all over the abdomen. 
J. mearnsi, p. 377. 
c. Centre of the back cinnamon-rufous, strongly contrasting 
with the dark slaty head; flanks grey. 
a® Upper mandible pale (pinkish in life); below darker grey. 
J. caniceps, p. 378. 
b? Upper mandible blackish ; below paler-grey. 
J. dorsalis, p. 380. 
White-winged Junco. Junco aikeni. 
A.O.U. Checklist no 566—Colorado Records—Aiken 72, p. 201; 
Ridgway 73, p. 613; Trippe 74, p. 145; Henshaw 75, p. 266; Drew 
81, p. 90; 85, p. 16; Allen & Brewster 83, p. 190; Beckham 87, 
p. 122; Morrison 88, p. 74; 89, p. 38; Cooke 97, pp. 104, 166, 215; 
Henderson 03, p. 236; 09, p. 237; Rockwell 08, p. 172; Cary 09, 
p. 182; Hersey & Rockwell 09, p. 120. 
Description.—Male—General colour above and below anteriorly, 
slaty-grey ; tips of the middle and greater wing-coverts, three pairs of 
outer-feathers, lower-breast and abdomen white; bill flesh-coloured. 
Length 6.90; wing 3-25; tail 3-05; culmen .48; tarsus -75. 
The female resembles the male, but is a shade paler in colour, and the 
wing-bands are not nearly so well marked, though there is considerable 
variation in this respect in both sexes. Some specimens have a distinct 
buffy wash on the back; these are probably young birds. 
