356 
BIRDS OF NEW MEXICO 
gray, whitish on throat, often with a few amethyst feathers. Young male: Similar 
to adult female, but feathers of upperparts more or less edged with huffy, tail double- 
rounded, and throat generally with a few amethyst feathers (in older ones similar 
feathers on crown). Young female: Similar to adult female but feathers of upper- 
parts edged with huffy. 
Comparisons. —The Costa is closely related to the Black-chinned but the females 
of Costa may be distinguished by normal instead of abruptly narrow six innermost 
primaries and round tipped instead of pointed tail feathers. (See Comparisons 
under Black-chinned Hummingbird, p. 354.) 
Range. — Breeds in Lower Sonoran Zone (preferably in arid) from south-central 
California (casual to central California), southern Nevada, and southwestern Utah 
south to southwestern New Mexico, southern Arizona, and southern Lower Califor¬ 
nia; winters from southern California and central-western Arizona to Sinaloa, 
Sonora, and Lower California. 
State Records. —The only record of the Costa Hummingbird in New Mexico is 
that of Frank Stephens, who in May, 1876, found one nesting on the Gila River, a 
few miles below Old Fort West. The species is common in California and Arizona, 
the above marking the easternmost limit of the range. It is a summer resident, 
retiring to Mexico for the winter.—W. W. Cooke. 
Nest. —Usually 1 to 6 feet from the ground on cactus, in vines, bushes, palo verde, 
and other trees, often on a dead branch; loosely or compactly made mainly of plant 
down, weed leaves, and bits of flower stems, sometimes also pieces of string, attached 
to the supporting branch by cobwebs; lined with down and occasionally small 
feathers; ornamented with bits of bark, paper, etc. and bound with web and cocoon 
silk. 
Food. —Insects found on plants and shrubs, as the squaw cabbage, milkweed, 
wild rose, sage, plum, and cherry and apricot blossoms. 
General Habits. —In southern California the Costa Humming¬ 
birds are common among sage and “greasewood” on the low hillsides 
near small ravines, and also in eucalyptus groves. In Tucson, Arizona, 
Mr. and Mrs. Swenk had the pleasure of watching them in their yard 
about the blossoming apricot trees, and found a beautiful nest in a 
vine over the doorway of a friend (1928, p. 27). 
The presence of the male, Mr. Woods finds, “is frequently announced 
by the two-or-three-syllabled whistling call with which he greets 
passing members of the tribe from his perch or salutes his mate as he 
hovers before her (1927, p. 301). Unlike the Black-chinned, Mr. J. B. 
Dixon says, the Costas “seem to enjoy each other’s company, and it 
is nothing unusual to find them almost in colonies, as many as five 
nests being located in a radius of fifty feet in an unusually well situated 
grove of oaks.” At other times rather quiet, at the beginning of the 
breeding season they are quite noisy, “chasing each other up, down, and 
around through the surrounding bushes and trees,” squeaking sharply 
as they go. Like the Black-chinned and other hummers, the male 
Costa performs a remarkable aerial dance. “When he locates his 
mate sitting on a tree, or more often on a low bush,” Mr. Dixon says, 
“he will ascend to an elevation of about one hundred feet and to one 
