511. 
179. 
535. 
FALCONIDZA—POLYBORINZ:: CARACARAS. 539 
the above species in dark rufous lower parts, and dusky, mottled inner webs of primaries.” 
(Ridgway.) Cuba; Florida. 
F. fuscicerules'cens. (Lat. fuscus, dark; cerulescens, bluish.) FEMORAL FALcon. 
Aptomapo Facon. Quite different from any of the foregoing species, though belonging to 
the sparrow hawk group (Tinnunculus) ; it has been made a separate subgenus (Rhyncho- 
falco). Bill robust, with large cere; irregular scutellation of tarsus continuous on the toes ; 
tarsus a little longer than middle toe without claw; 2d and 3d quills longest; Ist about equal 
to 4th; Ist and 2d emarginate on inner webs; 2d and 3d sinuate on outer webs. Size 
medium (among the smaller falcons); form slender; sexes alike. Adult $9: Above, uniforin 
plumbeous; tail with about 8 narrow white bars, and tipped with white, as are the secondaries ; 
primaries with numerous narrow white bars on inner webs, mostly being isolated transverse 
spots, reaching neither shaft nor inner edge of the feathers; the same pattern less definitely 
continued on to the secondaries. Side of head with a broad white or tawny postocular stripe, 
continuous with the narrowly white forehead, shading into orange-brown on the nape, where 
confluent with its fellow ; auriculars mostly white, set in the black of the side of the head, but 
continuous with the white of the throat, so that a black supra-auricular stripe meets a black 
mystacial stripe under the eye. Sides of body and a broad belly-band black, with or without 
numerous narrow white bars; the extent of this black very variable; it usually leaves the 
breast white or tawny, but in younger specimens the whole breast is streaked with black on a 
tawny ground. Throat usually white. Lining of wings blackish, spotted with white, the 
border mostly white or tawny. Flanks, flags, and crissum uniform tawny or orange-brown. 
Young sufficiently similar, but upper parts rather dark brown than plumbeous. Length 15.00 
or more; wing 10.00-11.00; tail 7.00-8.00; tarsus 1.75 ; middle toe without claw 1.50. A 
handsome hawk, well-known and wide-ranging in 8. and C. Am., reaching just over our Mex- 
ican border. Nest in trees or bushes; eggs 1.80 1.65, white, finely dotted with light brown, 
overlaid with blotches of dark brown. 
46. Subfamily POLYBORINZA: Caracaras. 
Anatomical characters of Falconine proper, in the scapular arrangement by which a pro- 
cess of the coracoid reaches the clavicle, the central tubercle of the extensively ossified nasal 
bones, the anterior keel of the palate, and the superorbital shield in « single piece; external 
characters very unlike those of Falconine, and general aspect vulturine. Bill toothless. 
Sternum single-notched on each side behind. Three or more primaries sinuate-emarginate on 
inner webs; 3d or 4th longest; 1st shorter than 5th. A small but remarkable group, com- 
bining some of the essential characters of falcons with others more vulture-like ; the species are 
chiefly terrestrial, rather sluggish, and feed much on carrion. The genera are Polyborus, 
Phaleobenus, Senex, Milvago, Ibycter, and Daptrius, all confined to America. 
POLY’BORUWS. (Gr. woAvSdpos, polyboros, very voracious. Fig. 379.) Caracaras. Bill 
long, high, much compressed, little hooked, the commissure nearly straight to the deflected 
end; cere ending anteriorly in a nearly straight vertical line; nostril high in the front upper 
corner of the cere, linear, oblique, its posterior end uppermost, its tubercle concealed. Chin 
and sides of head bristly, extensively denuded; a naked pectoral area; an occipital crest. 
Tibie shortly flagged. Tarsus nearly twice as long as middle toe without claw, almost 
entirely naked, chiefly reticulate, but in front broadly scutellate in single or double row; 
lateral toes of about equal lengths; hind toe much the shortest; claws long and little curved. 
Wings very long, with 3d and 4th quills longest, 2d and 5th next, Ist shorter than 6th or 7th ; 
outer 4 or 5 emarginate. Tail rounded, about 3 as long as wing. Comprising two or three 
species of large vulture-like carrion hawks, of terrestrial habits, and ambulatorial, not salta- 
torial, gait, P. cherivay, P. auduboni, and P. lutosus, of the warmer parts of America. 
P. au/duboni. (ToJ.J. Audubon.) Common Caracara. Ad. &@: General color blackish, 
