146 
ZOOLOGY. 
see what has disturbed his poultry yard. I believe it to be a constant resident, and to build 
in the Territor3^ — C. 
Cooper's hawk is a common bird of prey in Oregon and Washington Territories. I obtained 
numerous specimens of it at Puget Sound and Fort Dalles. The characteristic variations in 
size and color of this bird hold good in Oregon, scarcely any two specimens being there found 
that are alike. An undoubted specimen of the A. Cooperi, shot at Fort Steilacoom in Sep- 
tember, 1856, No. 5846, (590,) measured: length, 19; extent, 30 inches. — S. 
ACCIPITER MEXICANUS, Swain son. 
Blue-backed Hawk. 
AccipUer mexkanus, Sw. Faun. Bos. Am. Birds, p. 45, (1831.) 
Baird and Cassin, Gen. Kep. Birds, p. 17. 
Sp. Ch. — Almost exactly like A. Cooperi, but smaller ; back more brownish ; throat and under tail coverts, white ; other 
under parts more rufous, with white bars and spots ; dark streaks only on breast. Young much tinged with reddish above ; 
imderneath, yellowish ; each feather streaked and often barred near its base. Female : length, 17 to 18 inches ; wing, 9J 
to 10 ; tail, 9 ; extent, about 30. Male : length, 15 to 16 inches ; wing, 9 ; tail, 8. — C. 
This species of hawk I at first took for small individuals of the A. Cooperi^ but the smaller 
size, the larger proportionate size of the tarsi, and other peculiarities, induced me to examine 
the bird more carefully. Upon comparing the specimens with Cassin' s description of A. 3Iexi- 
canus I found that they accorded. 
An individual killed in the summer of 1856, at Port Townsend, Puget Sound, was shot near 
a salt marsh. While soaring about it resembled in its motions the common marsh hawk, or hen 
harrier. — S. 
ACCIPITER FUSCUS, Bonaparte. 
The Sharp-shinned Hawk. 
Falco fmcus and F. dtibim, Gm. Syst. Nat. I, 280, 281, (1788.) 
AccipUer fuscus, Bonaparte, Comp. List, Birds, p. 5. 
A. fuscus, (Gm.) Baird and Cassin, Gen. Eep., Birds, p. 18. — Newberey, P. R. R. Rep., vol. VI, Zool., p. 74. 
Falco velox and F. pennsylvanieus, Wilson, Am. Orn. V, 116, pi. 45, f. 1 and VI, p. 13, pi. 46, f. 1. 
Sp. Ch. — Almost exactly like the two preceding in color, but much smaller. Young: above brown, beneath like young of 
A. Cooperi in color. 
Female: length, 12 to 14 in.; wing, 7 J to 8; tail, 6 J to 7 inches, extent about 25 inches. 
Male: length, 11 to 12; wing, 6 to 6j; tail, 5 to 5iJ. 
No. 8514, (94,) Shoalwater bay, September, 1854. Length, 11. 50; extent, 21. 50 inches; male. 
This hawk I have not found common, and have observed only in the colder months. It has 
habits and flight much like the preceding, but, of course, preys on smaller birds. Its small size 
and long tail, besides its greater swiftness of wing, make it easily distinguishable from the 
pigeon hawk when flying. — C. 
The sharp-shinned hawk is quite common near Fort Steilacoom during the latter part of 
summer and in early autumn. Like the pigeon hawk, they are quite scarce during the breeding 
season in the more open country about the head of Puget Sound. They appear to descend 
from the mountains as soon as the young birds are well able to fly, and, in company with many 
other species of hawk, remain on the prairies for several months before retiring to the south. 
A few remain throughout the winter. — S. 
