528 Birds of Colorado 
88, p. 71; Lowe 92, p. 101; 94, p. 270; Cooke 97, pp. 18, 126, 223; 
Gilman 07, p. 195; Cary 09, p. 185; Warren 09, p. 17; Henderson 
09, p. 242. 
Description.—Male—Above bright ultramarine-blue, becoming dusky 
on the inner edges and tips of the wing-feathers ; » square patch of 
dark chestnut occupies the back and scapular region; below, the 
sides and a band across the chest chestnut, separating the blue of the 
throat from that of the rest of the under-parts, which fades to a grey 
on the abdomen and under tail-coverts; iris dark brown, bill and 
legs black. Length 6-0; wing 4:30; tail 2-75; culmen -45; 
tarsus -80. 
The female is much duller in colour ; the head is greyish-blue ; the 
rump, tail and wings a little brighter blueish, but far inferior to the 
male, while the chestnut of the back is replaced by dull brown; below 
the chestnut is much paler and the blue replaced by blue-grey ; outer 
primary edged with white. In the fall the blue and chestnut are 
slightly obscured by brownish tips to the feathers both above and 
below. A young bird of the year is dusky-grey above, spotted with 
white, and becoming rather bluer on the tail and wings ; below greyish, 
the feathers of the breast edged with dusky-brown, giving a squamated 
appearance. 
Distribution.—Breeding in the Rocky Mountain region from Colorado, 
south to Chihuahua and Durango in Mexico, wintering in New Mexico, 
western Texas, Sonora and southern California. 
This Bluebird is not very common in Colorado, and appears to be 
confined to the south of the State and to the eastern foothills and 
neighbouring plains. It has been met with as far north as Loveland, 
on April lst (Cooke). It arrives about the end of March and breeds 
in the foothills up to about 7,500 feet, and departs in October. The fol- 
lowing are breeding records: Boulder hills (Gale), Arkansas Divide, 
near Peyton, El Paso co., 7,500 feet (Aiken), West Monument Creek, 
El Paso co. (Allen & Brewster), Wet Mountains to 9,500 feet (Lowe), 
near Fort Lewis (Morrison & Gilman). It was not observed by Aiken 
at Limon, or by Thorne at Fort Lyon. Cary has recently reported 
seeing it near Uncompaghre Butte at about 9,000 feet, in July. This 
is the first record from Mesa co. 
Habits.—The Chestnut-backed Bluebird does not differ 
from the other Bluebirds in its habits. It prefers open 
ground and is frequently to be seen in small parties near 
ranches, perched on fences or telegraph wires, whence 
it darts off to pick up insects from the ground. 
