TBE WESTERN RED-TAIL. 215 



Emerson informs me that in one of their nests near Haywards, California, 

 containing a young Hawk still in the down, he found two gophers and a 

 steel trap containing a squirrel; and he also saw a pair of these birds fight- 

 ing or playing over a snake, which would be dropped by one of them and 

 caught by the other before it reached the ground, until finally the prize was 

 carried off. 



In his paper on "Birds from the Farallon Islands," Mr. Walter E. Bryant 

 makes the following statement regarding this subspecies: "Every spring the 

 island is visited by numbers of these Hawks. In 1882 they came in April, 

 about the time of the arrival of the Murres, leaving again in May. During 

 their short stay they fed almost exclusively upon the Murres, killing, in the 

 estimation of Mr. Emerson, several dozen a day."^ 



On the whole the Western Red-tail, viewed from an economic standpoint, 

 is far more beneficial than otherwise. 



Nidification begins rather early, and where the birds are not persistently 

 disturbed the old nests are resorted to and repaired from year to year. In 

 southern California full sets of eggs of this subspecies have been found as 

 early as February 20; usually, however, they do not lay much before March 

 10, and the majority not before April. Most of them nest in this month, not 

 only in California but in Arizona, New Mexico, and northwestern Texas also. 

 Even at points considerably farther north, as at Fort Lapwai, Idaho, I have 

 found full sets of eggs by April 10. In the mountains of Oregon, Washing- 

 ton, Idaho, Montana, and Wyoming they usually nest somewhat later, gen- 

 erally in the last week of April or the beginning of May. Mr. F. Stephens 

 has found this subspecies nesting as late as June 12, but in this case the birds 

 had most likely lost their first clutch. 



The nests are placed at various distances from the ground, sometimes in 

 quite low situations, and again at a great height, especially when placed near 

 the tops of tall redwood and pine trees, often fully 100 feet from the ground, 

 and practically inaccessible. Mr. W. E. D. Scott mentions finding nests of 

 this .species in southern Arizona as low as 10 feet, and one only 7 feet from 

 the ground. Their average height is from 30 to 50 feet. In their choice of 

 nesting sites, large cottonwoods, sycamores, and live oaks are generally 

 selected, while pines, redwood trees, junipers, mesquites, willows, and aspens 

 come in the order named. 



In southern Arizona they also nest occasionally in a sahuara, the giant 

 cactus peculiar to that region. On March 24, 1872, I found a nest of this 

 subspecies thus situated, which contained two partly incubated eggs. It was 

 a very large and bulky one, and had evidently been used for a number of 

 years, the sticks in the bottom of the nest being quite rotten. It was placed 

 between the main trunk and one of the arms of the cactus, about 12 feet 

 from the ground, and was found near the source of Rillitto Creek, Arizona. 

 The nest was rather flat on top, and fairly well lined with the inner bark of 



'Proceedings California Academy Sciences, 2d ser., Vol. i, 1888, p. 45. 



