CASSIN'S SPARROW 989 



and the song seems to come from a great distance. Several birds in 

 the same locality may sing this song, none of them paying any atten- 

 tion to any other one. 



The call note is a loud "tsip." Another common call is a rapid 

 "tzce, tzee, tzee." The latter call is used by both male and female 

 during courtship chases, by the young when chasing the parents, and 

 by any Anntering bird when it flushes unexpectedly and darts rapidly 

 away from the observer. 



Field marks. — Cassin's sparrow is one of the most nondescript of 

 all sparrows. It has no \Wng bars, eye rings, or tail markings, and 

 the head streakings are so fine as to be almost invisible. Its back 

 is dull gray, and the lighter under parts are unmarked in adults. 

 The long, rounded tail and flat-headed appearance are good field 

 marks. The flat head, combined with the thick bill, gives the bird 

 a sloping profile unusual in the Fringillidae. 



Enemies. — Herbert Friedmann (1934) lists six records of Cassin's 

 sparrow victimized by the dwarf cowbird. Margaret M. and Leonard 

 B. Nice (1924) reported "one bird killed accidently by prairie dog 

 poison." J. Van Tyne and G. M. Sutton (1937) found the remains 

 of a Cassin's sparrow a shrike had kiUed and impaled on a yucca leaf. 

 As with most groimd nesters, snakes probably are responsible for some 

 loss of eggs and young. The young in a nest near Midland, Texas 

 were found dead and almost completely eaten by large red ants from 

 an ant hiU under the nest bush. Whether the ants killed them or 

 started eating them after they were dead from some other cause we 

 could not determine. 



Fall and winter. — Cassin's sparrows withdraw from the northern 

 parts of their range in late October and November. A few winter 

 from southwestern Texas to southeastern Arizona. 



Allan R. PhiUips (1944) describes the unusual behavior of this 

 species in Arizona in the faU: "The Cassin's Sparrow appears in 

 Arizona in mid-July as an abundant fall transient, having migrated 

 west from the southern Great Plains. Most of the birds are adults. 

 They are in full song, with testes greatly enlarged, and may go so 

 far as to build nests, but so far as is known they do not complete 

 their nests nor lay any eggs. They decrease sharply in numbers at 

 the beginning of September, but some remain through the winter 

 and leave in early May." 



A. W. Anthony (1892) described this same post-breeding wandering 

 in southwestern New Mexico. He reported that the species appeared 

 in the extreme southwestern portion of Grant County after the 

 August rains and then remained common there until late fall. 



