Prairie-Falcon 185 



the longest ; the outer only, or the outer two, emarginate on the inner 

 web ; feet rather short, tarsus feathered or bare, without regular scutes. 

 This genus contains the Falcons and Kestrels, and is found all over 

 the world. 



Key of the Species. 



A. Larger ; wing over 1 1 ; only the outer primary emarginate. 



a. Clay-brown above ; below with dusky, Unear spots. 



F. mexicanus, p. 185. 



b. Slaty-blue above ; below transversely banded with dusky. 



F. p. anatum, ad., p. 187. 

 e. Blackish, edged with tawny above ; below streaked with dusky. 



F. p. anatum, juv., p. 187. 



B. Smaller, wing under 10 ; the two outer primaries emarginate. 



a. Tarsus scarcely as long as the middle toe without claw ; without 



vertical black stripes on the face. 



a^ Tail with traces at least of four black transverse bands, 

 including the broader subterminal one ; no white spots on 

 the outer webs of the primaries. F. columbarius, p. 188. 



b^ Tail with traces of five black transverse bands ; outer web 

 of primaries spotted with white. F. c. richardsoni, p. 189. 



b. Tarsus very clearly exceeding the middle toe without claw ; 



face with two vertical black stripes, 

 ai Smaller and more highly coloured. F. sparverius, p. 190. 

 b^ Larger and paler coloured. F. s. phalcena, p. 192. 



Prairie-Falcon. Falco mexicanus. 



A.O.U. Checklist no 355 — Colorado Records — Henshaw 75, p. 410 

 {F. lanarius polyagrus) ; Coues 77, p. 26 ; Scott 79, p. 96 ; Allen 

 & Brewster 83, p. 197 ; Drew 85, p. 17 ; Dille 87, p. 97 ; Morrison 89, 

 p. 65 ; Kellogg 90, p. 87 ; Lowe 94, p. 267 ; Cooke 97, p. 76 ; Hender- 

 son 03, p. 235, 09, p. 229 ; Oilman 07, p. 154 ; Richards 09, p. 164. 



Description. — Male — Above pale clay -brown, tinged with rusty 

 and indistinctly barred with pale bufiy anteriorly, and pale bluish-grey 

 posteriorly ; a white nuchal collar and dark patches on the side of the 

 face ; primaries ashy-brown, with paler tips and whitish bars on the 

 inner webs only, the outer one only with the inner web cut out ; below 

 white, marked most heavily on the flanks, less so on the belly, with 

 dusky, linear spots ; throat unmarked ; iris brown, bill bluish-horn, 

 yellow at the base ; cere and feet yellow. Length 17-0 ; wing 12 ; 

 tail 7'25 ; culmen -8 ; tarsus 2-1. 



The female is larger — wing 13'5, tail 8-2 — and has a more uniform 

 appearance above without the lighter bars. Young birds have more 



