250 LIFE HISTOEIBS OF NORTH AMEEICAlSr BIRDS. 



Mr. F. Stephens writes me: "Cassin's Kingbird is a winter resident in 

 southern California, but it is not very common. I have failed to find them here 

 during the breeding season, even in the mountains." 



It has not as yet been reported from southern Arizona as a winter resident. 

 I failed to notice them after October in the vicinity of Tucson, and beheve they 

 migrate regularly, returning from their winter homes in the south in March. 



Cassin's Kingbird is neither as noisy nor as quarrelsome as the preceding 

 species, and appears to be more of a mountain-loving bird and to nest at higher 

 altitudes. 



Dr. Edgar A. Mearns, United States Army, in his notes on Arizona Moun- 

 tain Birds, says: "Cassin's Kingbird breeds commonly throughout the pine 

 forests. I found it in the uppermost timber on San Francisco Mountain in June, 

 the altitude being nearly 12,000 feet. This conspicuous species likewise breeds 

 in the low valleys of Arizona, together with ^ the Arkansas Kingbird (Tyrannus 

 verticalis), nests of both species having been found at the same time in one Cot- 

 tonwood tree in the Verde Valley. On the Mogollon Mountains I saw them 

 attack Crows and Western Red-tailed Hawks, and drive them from the neigh- 

 borhood of their nests after the spirited fashion of the eastern Kingbird."^ 



Their food, like that of the other members of this family, consists princi- 

 pally of insects, and is obtained in a similar manner. 



Their call notes do not differ very much from those of the other Kingbirds, 

 but on the whole are perhaps less shrill and a trifle more melodious. While 

 they are possibly more common in the oak and pine belts in Arizona, I found 

 them by no means rare in the lowlands along the Santa Cruz River and Rillito 

 Creek, near Tucson, Arizona, during the summer of 1872, where I took a num- 

 ber of their nests. I consider them very late breeders, my earliest record being 

 June 14, when I took a set of four fresh eggs; but it is possible that I may have 

 overlooked the first broods entirely, as most all the nests found by me during 

 the month of June (about a dozen) contained fresh eggs. The season of 1872 

 was a very backward one, however, and this may account for the late nesting, 

 especially as Dr. Cooper is quoted in "History of North American Birds, 1874" 

 (Vol. II, p. 328), as finding Cassin's Kingbird breeding at San Diego, California, 

 as early as March 28. The earliest record I have is May 27, 1892 — a set of three 

 eggs containing large embryos, taken at Dog Spring, Grant County, New Mex- 

 ico, by Dr. E. A. Mearns, United States Army, and now in the United States 

 National Museum collection. This nest was located in a hackberry tree, near a 

 nest of Swainson's Hawk, containing two -eggs. 



The trees generally selected bythis species for nesting sites are pines, oaks, 

 Cottonwood, walnut, hackberry, and sycamores, and the nests are almost inva- 

 riably placed near the end of a horizontal limb, usually from 20 to 40 feet from 

 the ground, in positions where they are not easily reached. All of the nests 

 examined by me were placed in large cotton woods, with long spreading limbs, 

 and were saddled on one of these, well out toward the extremity. The majority 



' The Auk, Vol. VII, 1890, p. 255. 



