234 NORTH AMERICAN BIRDS. 



15.00-15.G0, tail 8.50-9.15, ciilmen .73-.SS, tarsus 2.40-2.70, 

 middle toe 1.G0-1.G5. Female: Length 20.85-21-50, extent 

 53.10, wing 10.50-17.40, tail 9,00-10.75, cuiraen .90-1.00, 

 tarsus 2.70-2.80, middle toe 1.80-1.85. Eggs 2-4, 2.19 X 

 1.72, dull white, usually spotted or speckled, chiefly oti 

 larger end, with umber brown. Mab. Middle America, 

 north to southern California, Arizona, Texas, etc., south to 

 northern South America. 



340. B, abbreviatus Cau. Zone-tailed Hawk, 

 c'. Outer webs of priniariLS distinctly spotted with white, buffy, or ochra- 

 ceous. 



Tail narrowly banded with white, buffy, or oehraceous, lesser wing- 

 coverts more or less rusty. Adult : Head, neck, and lower parts 

 more or less rusty, or cinnamon, the first two streaked with 

 dusky, the posterior lower parts more or less barred or trans- 

 versely spotted with whitish ; quills and tail black, the former 

 spotted on outer webs with white, the latter crossed bj' about 

 six narrow bands of and lipped with the same. Young: Head, 

 neck, and lower parts buffy or dull whitish, streaked and striped 

 or longitudinally sjjotted with dark brownish ; quills and tail 

 du.sky, the former extensively spotted on basal portion of outer 

 webs with buffy or oehraceous, the latter eros.sed by numer- 

 ous narrow bands of dull buffy or pale graj'ish brown (the 

 more anterior ones more oehraceous). Doicny young : Uniform 

 dull grayi.'ih white. Kest in large or tall trees. Eggs 2-4, 

 white, glaucon.s-whitc, buffy white, or pale brownish, variously 

 marked (spotted, blotched, or stained) with various shades of 

 brown. 

 d}. Adult with head and neck distinctly rusty. 



t'.' Adult : Eufous or rusty of anterior lower parts (chest and 

 breast) usually distinctly barred or transversely spotted 

 with white. Young: Lower parts usually with whitish 

 predominating, and basal half of outer webs of quills ex- 

 tensively oehraceous, buffy, or whitish. Male: Length 

 17.50-19.50, wing 11.25-13.50, tail 8.00-9.70, culmen .75-.90, 

 tarsus 2.70-3.25, middle toe 1.30-1.50. Female: Length 

 19.00-22 00, wing 13.35-14.25, tail 9.00-10.00, culmen .80- 

 .90, tarsus 3 10-3.20, middle toe 1.35-1.50. Eggs 2.13 X 

 1.G9. JLib. Eastern North America, north to Nova Scotia 

 and Canada, west to edge of Great Plains. 



339. B. lineatus (Gmel.). Red-shouldered Hawk. 



e'. Adult: Eufous or rusty of anterior lower j):irls (chest and 



breast) usually (alwaj's?) unbroken. Young: Lower parts 



with deep brownish or dusky prevailing; buH'y or ochra- 



