378 ZOOLOGY— BIRDS. 



districts from the edge of the plains upward. In Southern Colorado, it 

 appears to be the only one of its kind that passes the summer, yet it makes 

 up for the absence of its congeners by its own abundance. Though 

 most common on the creeks, at an altitude of about 7,000 feet, it also 

 reaches well up to timber line. 



A nest, found June 14, was saddled on a horizontal limb of a small 

 spruce ; a second, taken the 19th, was built on a small, swinging branch 

 of a cottonwood. They are less artistic structures than usual with birds 

 of this family, and are composed of cottony substances from plants, 

 covered externally with bits of bark and moss. Both contained two white 

 eggs, perfectly fresh. During the mating, and perhaps also through 

 the entire breeding season, the flight of the male is always accompanied 

 by a curious, loud, metallic, rattling noise, which he is enabled to produce 

 in some way by means of the attenuation of the outer primaries. This 

 is, I think, intentionally made, and is analogous to the love notes of 

 other birds. Though I saw many of these birds in the fall, it was only 

 very rarely that this whistling noise was heard, and then with greatly 

 diminished force. Though in summer it is of frequent occurrence throughout 

 this wide area, its numbers in certain localities in fall are still greater. 



Though there appears to exist an especially hostile feeling between this 

 and the last species yet in the fall, when migrating, they are brought by the 

 similarity of tastes and habits into the same localities, and their combined 

 numbers are in some favored spots in Arizona simply surprising. The beds 

 of bright flowers about Willow Spring, in the White Mountains, Arizona, 

 were alive with them in August ; and as they moved swiftly to and fro, now 

 surfeiting themselves on the sweets they here found so abundant, now 

 fighting with each other for possession of some such tempting prize as a 

 cluster of flowers, their rapid motions, and the beauty of their colors, intens- 

 ified by the bright sunlight — the gorgets of gold and purple contrasting 

 against their emerald and bright red bodies — conspired to an effect not soon 

 to be forgotten. 



