BLACK-CHINNED HUMMINGBIRD 353 



and portions of New Mexico. In the di\v foothills and canyons of 

 the Upper Austral Zone in this general region, it is one of the com- 

 monest of the hummingbirds. Dr. Joseph Grinnell (1898) says that 

 in Los Angeles County it is a "summer resident from the lowlands 

 to the summit of the mountains, but most abundant in the foothill 

 regions, where it breeds in the caiions in some years by the thousands. 

 * * * By the first of July, when the vegetation of the foothills 

 becomes dry, and floATers cease to bloom, the Hummingbirds are 

 found in countless thousands at higher elevations (6000 to 8500 feet) 

 where summer is just dawning." 



He says elsewhere (1914), referring to the Colorado Valley: "At 

 Ehrenberg the last week of March and opposite Cibola the first week 

 in April, the species was abundant in the desert washes, feeding 

 about the profusely blossoming palo verdes. * * * 



"The males were more seldom seen, and the females became closely 

 restricted to the willow strip along the river, in which association 

 we were convinced that this was the only species of hummingbird 

 breeding. The males were not seen in the willows, but only in the 

 mesquite association and up the desert washes. The females foraged 

 everywhere except on the desert mesa, but nested exclusively in the 

 willows." 



In southern Arizona we found the black-chinned hummingbird 

 to be the most abundant species of the family; its favorite haunts 

 seemed to be about the mouths of the canyons, where a line of syca- 

 mores followed the underground course of a mountain stream out 

 onto the plains; it was also commonly found in the small patches 

 of willows along the dry washes, where water had formerly flowed, 

 or where, probably, an underground supply still kept the trees and 

 shrubs alive. It was not seen in the mountains above 6,000 feet. 



Courtship. — The courtship flight of the black-chinned humming- 

 bird is much like that of the closely related eastern rubj^-throated 

 hummer, consisting mainly of the long, swinging, pendulumlike 

 swoops, with some variations. Laurence M. Huey (1924) describes 

 it very well as follows: 



The female was perched on a dead, horizontal limb about five feet from the 

 ground and the male took fliglit from a position approximately twenty feet 

 above her on the twig of a cottonwood, against the trunk of which I was 

 quietly resting. With a bold sweep and a whizzing noise made by flight, which 

 resembled that of the Costa Hummer except that the tone was not so intense, 

 he passed very close to her and headed up to a point about fifteen feet above. 

 There, while the upward motion died until a complete stop was reached, he 

 seemed to pat his wings together underneath him, causing a sound much like 

 that of a bathing bird floppiiig its wings in the water after they have become 

 thoroughly saturated. After a second downward swing, with the whizzing 

 noise, he rose to another point about fifteen feet up, where again the wing 

 flopping pei-formance '.v'as repeated. This U-shaped figure was repeated five 

 17S22."] — in 29 



