BIRDS OF NORTH AND MIDDLE AMERICA 219 



kk. General color slightly paler; the crown fuscous; the 

 breast markings ochraceous-tawny (St. Vincent, Gren- 

 ada; Grenadines). 



B. platypterus antillarum, ad. (p. 323) 

 jj. Size larger, wing, c? generally over 260, ? generally over 

 275 mm. (Canada to northern South America). 



B. platypterus platjrpterus, ad. (p. 306) 

 gg. Abdomen and flanks spotted, not barred, with reddish brown 

 or almost immaculate white. 

 h. Abdomen and flanks almost immaculate white, very sparsely 

 and narrowly streaked with brown (Antigua). 



B. platypterus insulicola, juv. (p. 320) 

 hh. Abdomen and flanks heavily spotted with brown, the ab- 

 dominal streaks often widening into large terminal spots. 

 i. Under wing covers and underparts generally much suffused 

 with tawny-buff (Lesser Antilles). 



B. platypterus rivierei, juv. (p. 322) 

 B. platypterus antillarum, juv. (p. 323) 

 a. Under wing coverts and underparts generally i^ure white. 

 B. platypterus platypterus, juv. (p. 309) 

 B. plats^jterus cubanensis, juv. (p. 317)" 

 dd. Four outer primaries emarginated or sinuated on inner web. 

 e. Outer webs of primaries spotted with white buffy, or ochraceous. 



B. lineatus and races " 



/. Underparts rufescent, at least the abdomen barred with rufous. 



g. Underparts, especially the breast, dark; rich dark cinnamon or 



cinnamon-rufous to orange-cinnamon. 



h. Breast usually uniform in color, not spotted with buffy; dark 



shaft lines of breast feathers not conspicuous (western 



North America) B. lineatus elegans, ad. (p. 287) 



hh. Breast spotted with buflfy ; dark shaft lines of breast feathers 

 conspicuous (coastal Texas to Louisiana). 



B. lineatus texanus, ad. (p. 289) 

 gg. Underparts paler, very light pinkish cinnamon to cinnamon-buff; 

 breast with some whitish barring. 

 h. Size larger; wings, cf usually over 315 mm., $ usually over 

 335 mm. (North America e. of Great Plains). 



B. lineatus lineatus, ad. (p. 280) 

 hh. Size smaller; wings, <^ usually under 315 mm., ? usually 

 under 335 mm. 

 i. Size very small, wings, cf under 280 mm., $ under 310 

 mm. (southern Florida and Florida Keys). 



B. lineatus extinaus, ad. (p. 292) 

 it. Size larger; wings, cf usually over 285 mm., $ usually 

 over 310 mm. (South Atlantic and Gulf States). 



B. lineatus alleni, ad. (p. 290) 



" These races are impossible to tell apart in juvenal plumage, as the slight 

 size difference found in adults is obscured by the degree of growth attained by 

 individual specimens. 



" The races of the red-shouldered hawk are all based on average characters 

 and consequently are not well adapted to the rigidities of a key. The characters 

 used in the key are therefore inapplicable in some instances, but they have been 

 chosen as fitting the majority of specimens. 



