136 
NORTH AMERICAN BIRDS. 
Adult with the blackish continuous and uniform. Wing, 12.35 - 14.50 ; 
tail, 9.80-11.00; culmen, .90-1.10; tarsus, 3.15-3.75; middle toe, 
1.65-2.00. Hob. Middle America, north into southern border of 
United States. (Harris's Buzzard.) var. harrisu 
Genus ONYCHOTES, Ridgway. (Page 125.) 
O. gruberi. Wing, 10.10 ; tail, 6.50 ; culmen, about .80 ; tarsus, 2.70 ; 
middle toe, 1.45; posterior claw 1.00, its digit .80. Immature (?}. Uniform 
grayish-umber, tinged with dull rufous on the neck ; lining of the wing and 
tibiae dull grayish-cinnamon. Primaries inclining to black, and showing 
just discernible, obscure hoary bars on their basal half. Tail brownish- 
gray, with a hoary cast nearer the shaft (not paler at the tip), and crossed 
with nine or ten narrow bars of dusky, these becoming hardly distinguish- 
able basally and terminally. Inner webs of the primaries plain white an- 
terior to their emargination. Head laterally and beneath obsoletely streaked 
with whitish. Hob. “California.” (Gruber's Hawk.) 
Genus BITTED, Cuvier. (Page 125.) 
A. Three outer primaries with their inner webs cut or emarginated. 
1. B. pennsylvanicus. Wing, 9.85-11.40; tail, 6.30- 8.00 ; culmen, .70- 
.80; tarsus, 2.15-2.80; middle toe, 1.20 -1.40. Third to fourth quill 
longest ; first shorter than seventh. Adult. Tail dull black, paler at the tip, 
crossed by two to four bands of dilute umber, or brownish-white, varying in 
width, but the last always broadest. Upper tail-coverts tipped and barred 
with white. Lower parts dull rufous-brown, nearly unbroken on the breast, 
but posteriorly much variegated with roundish transverse spots of white, 
forming broad transverse bars, interrupted by the dusky shaft. Upper 
parts dark umber, darker on the back. Young. Tail dull grayish-umber, 
growing darker terminally, narrowly tipped with whitish, and crossed by 
about six narrow and indistinct bands of dusky ; these gradually becoming 
obsolete basally, the last much broader. Lower parts white, or light ochra- 
ceous, with longitudinal spots of dark brown or blackish on the sides of the 
breast and abdomen, and roundish or transversely cordate ones on the sides,, 
flanks, and tibiae. A conspicuous “mustache ” on the cheeks, from the rictus 
down. Upper parts much as in the adult. Hdb. Eastern North America, 
and Middle America, south to Bogota and Caraccas. (Broad-winged Hawk.) 
2. B. swainsoni. > Wing, 12.00-17.00; tail, 6.50-9.00; culmen, .80-95; 
tarsus, 2.95 - 2.70 ; middle toe, 1.50 - 1.70. Third to fourth (usually third) 
quills longest ; first usually longer than seventh. Adult. Tail dark grayish- 
brown, sometimes with a hoary cast, crossed by five to seven, or more, 
narrow bands of dusky, usually very obscure, and becoming obsolete 
basally. Colors of other portions extremely variable ; the upper parts, 
however, continuous, unvariegated, dark brown, or blackish; the lower 
parts sometimes also entirely dusky, except the tail-coverts, which are 
always (?) barred with white. Normal plumage. A dark area covering the 
jugulum and breast, dull rufous in the <^ , and dark grayish-brown in the 9 • 
Other lower parts whitish, sometimes pure, and nearly immaculate, but 
usually more or less tinged with ocliraceous and rufous, and transversely 
