CALIFORNIA THRASHER 409 



certain occasions, sometimes "loudly and sweetly," and says that in 

 January the mated pair once sang together for about 15 minutes and 

 for shorter periods at other times. While winter and early spring 

 seem to be the seasons of greatest vocal activity, the thrasher's song 

 may be heard intermittently at almost any time of year. 



Like the mockingbird, the California thrasher often interpolates 

 into its song the utterances of other birds, including, according to 

 John Van Denburgh (1899), the flicker, house finch, quail, goldfinch, 

 and black-headed grosbeak. Ornithologists differ in their estimates 

 of the thrasher's ability as a mimic, most of them ranking it below 

 the mockingbird. My experience, however, has been the reverse, and 

 it seems probable that there are individuals in both species that are 

 outstandingly proficient. One midwinter day I was surprised to hear 

 the unmistakable buglelike notes of Bullock's oriole, a summer visitant, 

 and traced them to a California thrasher singing on the top of a bush. 

 Again, late in summer, the song of a thrasher contained notes re- 

 sembling those of the robin, a winter visitor here. These incidents 

 seem to indicate that the thrasher's memory is at least several months 

 long. 



Another striking demonstration of mimicry, perhaps by the same 

 thrasher, was the reproduction of the short howl or wail of the coyote. 

 Such was the ventriloquial effect and the perfection of the rendition 

 that even as I watched the bird singing on the top of a nearby bush, 

 it would have been difficult to believe that I was not actually hearing a 

 coyote in the distance had not the wails fitted perfectly between the 

 phrases of the song. 



Mrs. Allen (MS.) has noted the following imitations by thrashers 

 at Berkeley: long-tailed chat, red-tailed hawk, robin, ruby-crowned 

 kinglet, olive-sided flycatcher, titmouse, house wren, willow goldfinch, 

 California jay, quail, purple finch, European blackbird, frog, and 

 postman's whistle. Most of these were recorded in September. In 

 eight different years she found the song period marking the comple- 

 tion of the molt to begin in August ; in 11 years the starting of terri- 

 torial song ranged from December 21 to February 22. 



Field marks. — The California thrasher's long, decurved bill is suffi- 

 cient to distinguish it from any other bird ordinarily seen within its 

 territory. When its bill is not visible, it might be mistaken for a brown 

 towhee, but the tail is appreciably longer and is often tilted up. In and 

 around the passes leading from the Pacific slope to the desert, the range 

 of this species is said to slightly overlap the territories of the crissal 

 and LeConte's thrashers. From LeConte's the California thrasher is 

 distinguished by its darker color and somewhat longer, more curved 

 bill ; with the crissal it agrees rather closely in size, coloring, and shape 

 of bill, the identification being based principally on the color of the 

 under tail coverts, cinnamon in the California thrasher, cinnamon- 



