574 
BIRDS OF NEW MEXICO 
that of rest of underparts, which fade to gray on belly. Adult female in spring: 
Back dull brown, rump, tail, and wings bluish, outer tail feather and outer primary 
edged with white; anterior underparts grayish or brownish, sometimes tinged with 
blue, cinnamon of breast tinging chest and throat. Adult male in fall: Similar to 
summer male but blue of head, neck, and chest obscured by brownish feather tips; 
chestnut of back and scapulars duller, with paler feather tips, that of chest with 
paler tips. Adult female in fall and winter: Similar to summer female but head and 
back decidedly bluish, atid brown of underparts more chestnut. Young: Upperparts 
dark gray spotted with white, bluish on wings and tail; underparts grayish, feathers 
of breast squamated. 
Range. —Breeds mainly in Transition Zone from Utah, Colorado, and western 
Texas south to Durango and Zacatecas; winters from southern Utah and southern 
Colorado south to Sonora and Zacatecas. 
State Records. —The Chestnut-backed Bluebird is an abundant breeder in 
the middle districts of the mountains of New Mexico, breeding throughout the 
western part of the State and cast to Ribera, 6,000 feet, July 2, 1903 (Surber); 
base of Capitan Mountains, 6,200 feet, June 13-16, 1899 (Bailey); and probably 
in the Sacramento and the Guadalupe Mountains. There are no actual breeding 
records for these latter mountains, but the birds were seen there late in the summer— 
late in July and early in August—and it seems probable that they had not yet 
moved far from their nesting sites. It breeds south to the head of Mimbres River 
at 6,500 feet (Bailey); over all the Gila and Datil Reserves, at least as low as 6,500 
feet, near Chloride (Ligon); in the Pinos Altos Mountains (Fisher); and also prob¬ 
ably in the San Luis Mountains, as it was found there July 5, 1892 (Mearns). lln 
the north it is common in the northern part of Santa Fe County, 7,500 to 9,000 
feet, fresh eggs being found May 20-June 20 (Jensen, 1922)4 A nest with young 
was noted at Glorieta, 7,400 feet, about July 8, 1903; and birds were seen at 8,600 
feet on July 15 and at 10,200 feet on July 21 (Bailey). It seems to breed most 
commonly at 6,500-8,000 feet. It breeds so early, nesting sometimes in March, 
that a mere record of presence during the summer is rather unsafe for use as indi¬ 
cating breeding. Even by June 18 in 1905, old and young had already gathered 
in flocks near Fort Wingate, 7,000 feet (Hollister); although at that time one pair 
was feeding a second brood; while by the middle of July flocks of old and fully 
grown young were as well established as during the fall. The date when these 
flocks begin to spread beyond their breeding range has not yet been determined. 
The fall migration reaches its height in September and during this month the 
species is one of the most common at 7,000-9,000 feet in the mountains of northern 
and central New Mexico. At Aragon in the Tularosa Range it was also very 
abundant in 1915, migration being well under way by September 15 and continuing 
until October 7 (Ligon). It was seen as high as 10,500 feet September 4, 1906, on 
Santa Clara Mountain, and at 10,000 feet October 3, 1906, in the Pinyon Moun¬ 
tains (Bailey). It ranged east to Catskill the middle of September, 1903 (Howell); 
and by August 9, 1908, had already reached the Animas Mountains (Goldman). 
In the Sangre de Cristos it was seen at 8,000 feet on August 19, 1903, and was 
8 till present at Willis, 7,800 feet, October 10, 1883 (Hcnshaw); also at 10,200 feet 
in the Gallinas Mountains, October 7, 1904 (Bailey). 
In winter it remains in New Mexico and comes into the lower part of the valleys, 
to Mesilla, 3,800 feet (Ford); [it was common on the Rio Grande Bird Reserve 
(Elephant Butte), November 23-December 9, 1916]; in the Guadalupe Mountains, 
January, 1915 (Willett);.and to the Gila River, 4,000 feet (Stephens). It remains 
