April 1904] BIRDS OF THE HUACHUCA MOUNTAINS, ARIZONA. 53 



Dendroica olivacea (Giraud). Olive Warbler. 



I have, not found this species very abundant in the Huachucas at 

 any time, but it is probably resident to some extent, for I secured an 

 adult male on February 21, when the snow was deep on the ground. 

 During March I saw several more, all adult males and single birds, 

 usually with a troop of Pygmy Nuthatches ; but it was not until the first 

 of April, when the other warblers were arriving, that they became at all 

 abundant. In 1902, they were few in numbers and I did not get many 

 specimens, in fact but two adult males were observed ; but in 1903 they 

 became fairly abundant, particularly in April, when many small flocks 

 of five or six birds each, were seen. I found them only in the pine forests 

 of the highest parts of the mountains, even in cold weather none bein^ 

 seen below 8500 feet ; and more were secured above 9000 feet than below 

 it. They were seldom in company with other warblers, but when not 

 alone, associated with nuthatches and creepers. In their actions they 

 are more like vireos than warblers, clambering slowly and deliberately 

 over the branches in the search for food ; and uttering at frequent inter- 

 vals a liquid note much like that of a bluebird, but ventriloquial in its 

 effect, and very difficult to locate. Though frequenting the tree tops to 

 a great extent, they seem singularly tame and unsuspicious, and several 

 times I have had one feeding in some of the lower branches, within arm's 

 reach of me without it's showing the least sign of fear. 



The male birds seem to take at least two years in acquiring the adult 

 plumage, being indistinguishable from the female the first year, and I 

 was surprised at the large proportion of birds in this immature plumage 

 that were seen. At a very liberal estimate I should say that the males in 

 adult plumage comprised barely a third of the birds seen in the spring; 

 while in the late summer, when the flocks of juveniles appeared on the 

 scene, the proportion of perfect plumaged males was, of course, much 

 smaller. The male bird breeds in the immature plumage, for on June 21, 

 1902, I assisted Mr. O. W. Howard in securing a nest, containing four 

 eggs, the parents of which were indistinguishable in color and markings. 



About the middle of July young birds began to appear, and through- 

 out August young and old were seen together in small flocks. 



Dendroica aestiva sonorana Brewster. Sonoran Yellow Warbler. 



A common summer resident along the San Pedro River. It is possi- 

 ble that this species occasionally breeds in the Huachucas, for on sev- 

 eral occasions about the middle of June, 1902, I saw a single bird, a 

 female, at the same spot, a small clump of willows in a canyon at an 

 altitude of about 5500 feet. This warbler does not occur in the moun- 

 tains at all during the spring migration, but in August, 1902, it was 

 fairly abundant up to 6000 feet, the first seen being on August 9, and 

 most of those observed being immature birds. An adult female taken 

 August 26th, in fresh autumnal plumage, is very curiously colored; nor- 

 m^llv marked below, but the dark olive-green of the upper parts, wings 

 and tail, irregularly blotched with bright yellow; so that in the char- 

 acter of coloration it closely resembles a tame canary. 



Dendroica aestiva brewsteri Grinnell. Western Yellow Warbler. 



From May 8 to 19, 1903, I found Yellow Warblers in limited num- 

 bers in some of the washes immediately below the mountains. At the 

 time I took them to be sonorana, but the nine specimens I secured ,five 

 males and four females, prove to be indistinguishable from California 

 birds; and were probably migrants en route for the Pacific Coast to- 



