FALCOK ID.K — THE FALCONS. 



177 



exclusive of some of the West India Islands. North and south of the 

 Isthmus it is modified into geographical races, the southern of wliich is var. 

 tharus, Mol., and the northern var. atitluhoni, Cass. 



The closely related genera Phakohcenas, Milvago, Ihyctcr, and Daptrius 

 are peculiar to South America and the southern portion of Middle America, 

 most of them being represented by two or more species. They all form 

 a well-marked and i^eculiarly American group, for which I shall retain 

 Schlegel's term Pohjhori. 



Their habits are quite different in many respects from tliose of other 

 Falconidw, for they combine in many respects the habits of the gallinaceous 

 birds and those of the \'ultures. They are terrestrial, running and walking 

 gracefidly, with the exception of the species of Ihyctcr and Daptrius, which 

 are more arboreal than the others, and are said also to feed cliiefly upon 

 insects, instead of carrion. 



Species and Races. 



P. tharus. Wing-, 14.50-17.70; tail, 10.00-11.00; culraen, 1.20-1.48; 

 tarsus, 3.20 - 4.20 ; middle toe, 1.75 - 2.30. 



AduU. Forehead, crown, occiput, back, rump, abdomen, sides, and 

 tibi», and terminal zone of the tail, dull black. Neck, breast, tail- 

 coverts, and tail, dingy whitish. Interscapulars, breast, and tail with 

 transverse dusky bars. 



Young. Blackish areas replaced by dull brown ; region of the trans- 

 verse bars marked, instead, with longitudinal stripes. 



Adult. Whole body, with middle wing-coverts, variegated with 

 transverse bars of black and white ; tail-coverts barred. Terminal 

 zone of the tail about 2.00 wide. Young. Longitudinal stripes 

 over the whole head and body, except throat, cheeks, and tail- 

 coverts ; tail-coverts transversely barred. Ilab. South America. 



var. tharus} 



1 Polybonis tharus. Falco tharus, Molina, Sp. Chil. p. 264, 343; 1782. Pohjhorus llmrus, 

 Strickl. Oru. Syn. 1, 19, 1855. Falco cheriway, Jacq. Beytrag. p. 17, pi. iv, 1784. Polijho- 

 rus cherkoay. Rich. Schomb. Vers. Faun. Brit. Guiana, p. 741, 1840. Falco plancus, Gmel. 

 Syst. Nat. p. 257, 1789. Falco brasiliensis, Gmel. Syst. Nat. p. 262, 1789 (et AucT.). 

 Pobjbonts brasiliensis, ViG. Zool. Journ. I, 320, 1824. Cnracara mlrjaris. Less. Tr. Orn. p. 

 34 ; 1831. Polijborus vuhjaris, Spix. Av. Bras. I, pi. i, a. 



AduU male (21,850, South Amciioa ; T. R. Peale). Forehead, crown, oucijiut, aud wings 

 lirownish-black ; middle wing-coverts fainter, with obscure whitish bars ; primaries white in the 

 middle (just beyond tlie coverts), tliis portion having obsolete washes of grayish, in form of 

 faintly indicated transverse bars ; basal three-fourths of the tail white, with numerous narrow, 

 washed bars of grayish, these becoming more faint toward the base ; tail with a terminal zone of 

 black, about two inches broad. Cheeks, chin, and throat soiled white, iinvariiul ; body in general 

 (including neck, breast, sides, abdomen, back, and scapulars) transversely barred with black and 

 w hite, the white prevailing anteriorly ; beneath, the black bars grow gradually wider posteriorly, 

 giving the tibiie and femorals a uniformly blackish aj)pearance ; on the back and scapulars also 

 the black bars exceed the white in width, but they are very sharply defined, regular, and con- 

 tinuous ; rump, upper and lower tail-coverts, white, with numerous faint bars of gniyisli. Under 

 side of the wing black ; outer six primaries wliite in the middle portion, beyond the coverts, this 

 patch extending obliquely across ; secondaries rather broadly barred on basal two-thirds with 

 black and wldte, leaving tlie teruiinal third unvaried. Tliird cpnll longest ; fourth scarcely 

 VOL. Ill, 23 



