204 University of California Publications in Zoology [Vol. 12 



the usual habitat. Occasionally dense growths of very young willows, 

 being then similar in habit to tules, offered the proper conditions. 

 Along the lower course of the river, thickets of cane which clothed the 

 abrupt banks were the chief resort. Where tules failed, as near Pilot 

 Knob, this was the only accepted cover. On April 17, as we floated 

 through Canebrake Canon, three to seven miles below Picacho, the 

 songs of yellowthroats were heard almost continually. Here they were 

 inhabiting the jungles of cane which grew down into the river along 

 both shores. Unfortunately we did not have the time to devote to 

 search for nests, and 'information in regard to breeding habits is 

 lacking. 



Geothlypis trichas occidentalis Brewster 



Western Yellowthroat 



Occurred as a migrant along the valley, as noted under the pre- 

 ceding heading. The four specimens taken and referred to this sub- 

 species are all males, and were obtained as follows : No. 13722, Blythe, 

 California side, March 23 ; 13724, ten miles below Cibola, Arizona side, 

 April 9 ; 13726, 13727, twenty miles north of Picacho, California side, 

 April 11 and 12. These migrants were quite likely bound for the 

 Great Basin to the northward, being indistinguishable from specimens 

 from northern Nevada. 



Icteria virens longicauda Lawrence 

 Long-tailed Chat 



First seen April 25, above Laguna, one individual; three in the 

 same place the next day. On the 27th, at Potholes, several were seen ; 

 and thenceforth, at Potholes and four miles below, five miles northeast 

 of Yuma, and on both sides of the river in the vicinity of Pilot Knob, 

 chats were abundant. Twenty-four specimens were taken, nos. 13769- 

 13792. 



There is in the Museum a skin (no. 6423) taken by J. O. Cooper at 

 Fort Mohave, April 25, 1861. 



This bird was everywhere closely confined to the willow associa- 

 tion, at any rate never seen beyond the arrowweed. In point of actual 

 numbers, they were probably not so numerous as yellow warblers or 

 song sparrows; but in volume of noise they exceeded all other birds 

 combined. These chats of the Colorado possess an amazingly large 

 vocabulary in imitation of other sounds. On May 3 a few minutes of 



