276 HABITS OF AUDUBON'S WARBLER 



the stunted pines of the timber-line to the deciduous trees and 

 bushes bordering the streams of the Plains, but during the 

 breeding season restricted to an altitude of 8,000 to 10,000 feet, 

 where they rear their young in the fastnesses of the pines and 

 aspens. He found it as early as April 16, but it does not be- 

 come numerous till some time afterward. Henshaw saw it about 

 Denver early in May, and found it tolerably common on the 

 pine-clad mountains of Southern Colorado from about 9,000 feet 

 upward. The birds had paired by the 1st of June, and a fin- 

 ished but still empty nest was discovered a week later on the 

 top of a small spruce some thirty feet high. This nest was 

 composed of bark strips firmly and neatly woven, with a lining 

 of fine grasses; it was four inches in diameter and an inch deep. 

 In Arizona, the same diligent and observing naturalist ascer- 

 tained that these Warblers breed in the White Mountains, 

 where he took young just from the nest on the 12th of July, 

 even so far south as Mount Graham, where the young birds 

 were just beginning their new plumage on the 1st of August. 

 At Fort Whipple, in the same Territory, I found these Warblers 

 to be extremely abundant as much so as I ever saw Yellow- 

 rumps in the East during both the vernal and the autumnal 

 migrations. I thought then that they bred in the neighboring 

 mountains at higher elevations, and am now satisfied that such 

 is the case. I used to find them while they were on the move 

 in almost any situation, but they were specially conspicuous by 

 reason of their numbers and their activity in the cottonwood 

 trees and mixed undergrowth along the various mountain 

 streams from the 20th of April to the 10th of May, and again 

 during the month of October. They were also seen occasionally 

 during the winter, even at this elevation, and Dr. Cooper attests 

 their presence in numbers at the same season along the Colo- 

 rado River, at Fort Mojave. The experience of the last named 

 with the birds in California accords with what has gone before. 

 He obtained newly-fledged birds at Lake Tahoe in September, 

 and considers it probable that they breed throughout the 

 higher ranges of the Sierra Nevada. At Santa Cruz, latitude 

 37, and down to sea-level, the birds did not appear until the 

 end of September ; some winter there ; about the 20th of March, 

 the dull plain garb is quickly exchanged for the gay vernal 

 attire, and the birds are off by the middle of April. Great 

 numbers, he says, winter in various portions of Southern Cali- 

 fornia, where they flutter and chirp among the weeds of the 



