236 HUMMINGBIRDS 



Distribution. Breeds in Transition and Upper Sonoran zones from 

 British Columbia south to Lower California and from the Rocky Moun- 

 tains and Texas to the Pacific ; winters in Mexico. 



Nest. In trees or bushes 4 to 8 feet from the ground, made of white 

 or sponge-colored plant down, covered with spider web, sometimes with 

 addition of leaves or flowers. Eggs : 2 or 3, white. 



Food. Largely minute insects. 



In southern California the black-chinned hummer may often be 

 seen sunning himself on an oak twig, his dull black throat relieved 

 by a violet band that glints green and blue as he turns his head. 

 Ordinarily he seems the quietest, most unemotional of humming- 

 birds, but if fortunate you may come on him when performing his 

 aerial love-dance. One that I once watched took his stand below 

 his lady's perch and fixing his eyes upon her swung shuttling from 

 side to side in an arc, with the sound and regularity of a machine. 

 He never turned around or took his eyes from hers, but at the end 

 of the arc less than a yard in length always threw himself back 

 by a quick spread of his tail. She sat as if hypnotized, her long bill 

 turning as he turned, her eyes following every motion with droll 

 absorption. In spite of her flattering attention, however, when his 

 dance was over and he looked up for approval, she apparently made 

 some slighting remark, for he whizzed off in a hurry and was seen 

 no more. 



In Los Angeles County, California, Mr. Grinnell says black-chins 

 are summer residents from the lowlands to the tops of the moun- 

 tains, but most abundant in the foothills, where they breed in can- 

 yons some years by the thousands. Their numbers vary with the 

 rainfall, as the abundant flowering plants that follow a wet winter 

 afford them ample food. At Phoenix, Arizona, Mr. Bailey found 

 that one of their favorite feeding flowers was the desert Fouquiera. 



QENTJS CALYPTE. 



General Characters. Adult males with tail emarginate or 

 slightly forked, outside feathers abruptly narrower 

 than the rest. Adult females with outer tail feath- 

 ers decidedly narrower than the rest, but with broad 

 rounded end. 



i 



Fig. 308. KEY TO ADULTS. 



1. Males with gorget and top of head purplish red ; females with under 

 parts brownish gray anna, p. 237. 



1'. Males with gorget and top of head metallic violet ; females with under 

 parts white costse, p. 236. 



430. Calypte costse (Bourc.). COSTA HUMMINGBIRD. 

 Adult male. Head, gorget, and long faring ruff brilliantly burnished 



