310 LIFE HISTORIES OP NORTH AMERICAN BIRDS. 



Like most of our Raptores the Sparrow Hawk, I believe, remains paired 

 throughout life; at any rate they certainly appear to be already so on their 

 return from their winter homes. They usually arrive on the old breeding 

 grounds in the central portions of their range about the middle of March, 

 some seasons not before the beginning of April, and at later dates farther to 

 the northward. In Florida nidification begins about the middle of March, 

 sometimes in the last half of February; in southern Arizona, southern Texas, 

 and southern California about the first week in April; in the Middle States 

 from April 15 to May 10, and in the more northern States from May 1 to 

 June 1; in the Rocky Mountain region and thence westward to Oregon, 

 Idaho, and Washington rarely before May 15, and usually during the last 

 part of this month and the first ten days in June, and in the more northern 

 portions of its range during the first two weeks in June. 



The most common nesting place of the Sparrow Hawk is in holes of 

 trees, either natural cavities or the abandoned excavations of our larger 

 Woodpeckers. In regions where such sites are not readily obtainable, it 

 resorts to holes in sandstone cliffs and clay banks. Occasionally a pair will 

 nest in some dark corner in a barn, and even dovecots have been known 

 to be appropriated. Such an instance is mentioned in the "History of North 

 American Birds, 1874" (Vol. m, p. 174). Several observers report their 

 nesting in Magpies' nests in the West, and Mr. H. R. Taylor states: "Of 

 twelve sets of eggs of the Sparrow Hawk taken this year, in San Benito 

 County, California, by a friend and myself, all but two were found in Mag- 

 pies' nests, and these were placed one in a hole in an oak and the other in 

 a cavity in a bank on the San Benito River." 1 



While such nests may be resorted to in certain localities, it is by no 

 means a constant habit with this species. I believe there are few places in 

 the United States where the Black-billed Magpie (Pica pica hudsonica) is more 

 abundant than in the vicinity of the Nez Perce - Indian Reservation in Idaho 

 and the Sparrow Hawk is also common there, yet I never found a pair 

 occupying a Magpie's nest, although the ordinary nesting sites used bj it are 

 rare on account of the scarcity of large timber. According to some observ- 

 ers they are also said to occasionally occupy open nests, but such instances 

 must be very rare. Mr. Lynds Jones, of Grrinnell, Iowa, informs me that 

 he has found them breeding in open nests, usually old Crows' nests, and 

 that very little or no new material is used, the old lining being simply 

 rearranged. I have had excellent opportunities to study the nesting habits 

 of this species, and only in one single instance had I reason to suspect that 

 an open nest was used, and this was placed in the extreme top of a tall Cot- 

 tonwood tree on Lapwai Creek, Idaho, and was inaccessible. I repeatedly 

 saw one of these birds sitting on the edge of this nest, which appeared to be 

 rather a frail structure, if a nest at all, but it is very probable that it was 

 made use of more as a perch to rest on, and that there was a cavity some- 

 where in the upper part of the tree which I failed to notice. 



1 Ornithologist and Oologisfc, Vol. xm, 1838, p. 95. 



