186 BULLETIN 16 7, UNITED STATES NATIONAL MUSEUM 



near the nest. The nest is made of whatever small sticks or twigs 

 are easily available, mixed with strips of inner bark, dry leaves, 

 iisnea, mosses, lichens, twigs of evergreens with needles, and other 

 light materials ; the inner cavity is neatly lined with finer shreds of 

 inner bark, softer mosses or lichens, and fresh sprigs of pine, cedar, 

 or hemlock, producing a pretty ejffect, with a sprinkling of white 

 down from the hawk's breast. The nests vary considerably in size; 

 an average nest would measure about 24 by 18 inches in outside 

 diameter, the inner cavity about 8 inches in diameter and 2 or 3 

 inches deep, and the height, or thickness, 8 to 12 inches. The largest 

 nest that I have measured was 36 inches in longest diameter, 18 

 inches high, and hollowed to a depth of 6 inches; the smallest 

 measured only 16 by 14 inches in diameter, 7 inches high, and hol- 

 lowed only 2 inches. Dr. Harry C. Oberholser (1896) gives the 

 measurements of 10 Ohio nests; they exceed my average in size 

 but not my largest except in height ; two of his nests were 27 and 28 

 inches high. 



Our experience is that the red-tailed and red-shouldered hawks 

 never nest near together and that the same is true of the Cooper's 

 and sharp-shinned hawlvs, these being two pairs of competitive and 

 antagonistic species; we have, however, occasionally found one of 

 the Buteos nesting in the same woods with one of the Accipiters. 

 But Dr. William L. Ralph (Bendire, 1892) saj^s: "I have known 

 the Red-tailed and Red-shouldered Hawks and the Great Horned 

 Owl to nest near one another in a small wood, and on one occasion I 

 found a pair of each of the Sharp-shinned, Cooper's, and Red- 

 shouldered Hawks, and of the Long-eared Owl breeding so near to- 

 gether that I could stand beside the nest of a Ruffed Grouse, which 

 was close by also, and throw a stone to any of the others." 



I have always considered the red-shouldered hawk and the barred 

 owl as tolerant, complementary species, frequenting similar haunts 

 and living on similar food, one hunting the territory by day and the 

 other by night. We often find them in the same woods and 

 using the same nests alternately, occasionally both laying eggs in 

 the same nest the same season, resulting in a mixed set of eggs on 

 which one or both species may incubate. Walter A. Goelitz (1916) 

 has described and photographed a tree containing nests of both hawk 

 and owl within a few feet of each other. 



Some slight differences are noticeable in nesting habits in different 

 parts of the country. The choice of a tree depends on the type of 

 heavy timber prevailing, as the hawivs choose whatever large trees 

 are available. In New York Stale, Dr. Ralph (Bendire, 1892) says 

 that the}^ nest in birch, ash, maple, and beech trees, with a preference 

 for the first two. William A. and George M. Smith have sent me 



