234 
NORTH AMERICAN BIRDS. 
15.00-15.60, tail 8.50-9.15, culmen .73-.88, tarsus 2.40-2.70, 
niddle toe 1.60-1.65. Female: Length 20.85-21-50, extent 
53.10, wing 16.50-17.40, tail 9.00-10.75, culmen .90-1.00, 
tarsus 2.70-2.80, middle toe 1.80-1.85. Hggs 2-4, 2.19 x 
1.72, dull white, usually spotted or speckled, chiefly on 
larger end, with umber brown. Hab. Middle America, 
north to southern California, Arizona, Texas, etc., south to 
northern South America. 
340. B. abbreviatus Cas. Zone-tailed Hawk. 
¢. Outer webs of primaries distinctly spotted with white, buffy, or ochra- 
ceous. 
Tail narrowly banded with white, buffy, or ochraceous, 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 by about 
six narrow bands of and tipped with the same. Young: Head, 
neck, and lower parts buffy or dull whitish, streaked and striped 
or longitudinally spotted with dark brownish; quills and tail 
dusky, the former extensively spotted on basal portion of outer 
webs with buffy or ochraceous, the latter crossed by numer- 
ous narrow bands of dull buffy or pale grayish brown (the 
more anterior ones more ochraceous). Downy young: Uniform 
dull grayish white. Vest in large or tall trees. Hggs 2-4, 
white, glaucous-white, buffy white, or pale brownish, variously 
marked (spotted, blotched, or stained) with various shades of 
brown. 
@. Adult with head and neck distinctly rusty. 
e. Adult: Rufous 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 ochraceous, 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 135-150. Eggs 2.13 x 
1.69. Hab. Eastern North America, north to Nova Scotia 
and Canada, west to edge of Great Plains. 
339. B. lineatus (GmEL.). Red-shouldered Hawk. 
e’. Adult: Rufous or rusty of anterior lower parts (chest and 
breast) usually (always?) unbroken. Young: Lower parts 
with deep brownish or dusky prevailing; buffy or ochra- 
