458 Field Museum of Natural History — Zoology, Vol. IX. 



Cooper's Hawk. 



The nest is built in a tree, usually at a considerable distance from 

 the ground (from 30 to 60 feet^. The eggs are usually 3 or 4 in number, 

 and measure about 1.95 x 1.50 inches. They are grayish white, some- 

 times pale bluish white, as a rule without markings, although occa- 

 sionally showing a few pale brown spots. 



The following sets of eggs are contained in the Field Museum col- 

 lection: 5 eggs, Chicago, 111., May 18, 1904; i egg. Lake Forest, 111., 

 May 18, 1903; 4 eggs, Grinnell, Iowa, May 4, 1893; 4 eggs. Lake 

 Forest, 111., May 16, 1907. 



Genus ASTUR Lacepede. 



157. Astur atricapillus (WiLS.). 



American Goshawk. 



Accipiter atricapillus (Wils.). A. O. U. Check List, 1895, p. 129. 



Distr. : Greater portion of North America north of the Middle 

 states; breeds from northern border of United States northward. 



Adult male and female : Back and wings, slaty gray, the shafts of the 

 feathers on the back darker; entire under parts, thickly barred with 

 gray and white, the shafts of the feathers, dusky, showing fine lines; 

 upper surface of primaries showing faint, indistinct, grayish brown 

 dark bars, and marked with more or less white on the inner webs; 

 top and sides of head, dusky, a whitish streak extending backwards 

 from above the eye; tail feathers with imperfect, indistinct, dusky 

 bars and narrowly tipped with whitish; bill, lead color; feet, yellow- 

 ish. 



