528 Birds of Colorado 



88, p. 71 ; Lowe 92, p. 101 ; 94, p. 270 ; Cooke 97, pp. 18, 126, 223 ; 

 Oilman 07, p. 195 ; Cary 09, p. 185 ; Warren 09, p. 17 ; Henderson 

 09, p. 242. 



Description. — Male — Above bright ultramarine-blue, becoming diasky 

 on the inner edges and tips of the wing-feathers ; a 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 

 r\imp, tail and wings a httle 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 

 shghtly 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 1st (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 Monimaent Creek, 

 El Paso CO. (Allen & Brewster), Wet Mountains to 9,500 feet (Lowe), 

 near Fort Lewis (Morrison & Oilman). It was not observed by Aiken 

 at Limon, or by Thome 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. 



