■U'A BIRDS OF n^LINOIS. 



Genus BUTEO Cuvii-.n. 



Buleo Cuv. Loc. Annt. Corap. 1. 1800. tnlil. oIb. Typo. Fairo buteo Likn. 



Craxirex O0UI.D. Voy. IJoiic. Birds. IWl.i". Type, I'otuhomii galapaooentif OoutD. 



Tachulriorchi!) Kkvv. CInss. 8nug. Yoc. 1M4. \ii. Typo. Faho pleroclet Temk..- 



Jiutfo athiramlatus ViEILL. 

 Poeriliiiilfrtiif Kaup. Isls. IMii. *.3. Typo. Falco peunfulratiiriii Wu*. 

 Uuteola ItONAP. C'ompt. Reud. xll. ISVi. (Kl. Typo. Iluteo hrarUviirua ViKILL. 



Gen. Cbau. Form robust nn<l lu-uvy. tlio wlnKs long and mtlior pointed, tlio toil 

 iiiodoriite iiiul rounded, tln' Idlt nnd foot stronir. 11111 liitiTinodiiilo between Unit of .ludir 

 and tliut of Parnhuleu. Wine Ions and rather pointed, the third to llflh qulU longest, tho 

 llrst shorter than eluhth: throo or four with Inner webs omiirelnated. Tall modorato, 

 slichtly rounded. 



A. Four outer primaries with inner webs emareinatod. 

 a. Tarsus more than twlee as long as the middle too. 



1. B. lineatug. Tail always rlusky. crossed by white or bulTy narrow bands; outer 

 webs of primaries, anterior to their omarKlnatlonB. more or loss spotted with 

 white or ochraceous. Adult. Lower parts rufous (varylnc In intensity), more or 

 less barred or transversely spotted with white (breast sometimes nearly uniform 

 rufous). Tail and iirimarlos slate-blaek. the former barred, the latter spotted on 

 outer webs with pure white; lesser winK-envurts dark rufous or ehestnut. Young. 

 Lower parts dull wlillish or bulTy, louKltudinally striped with dusky. Triniiirles 

 and tall brownish ilusky. the former erossed by narrow bands of pali' grayish 

 lirown, Iniffy. or dull wliilish, the latter spotted towards base with the same. Mnle. 

 Wine. lifKi-ia.'-.O; tail. 7.T»-it.70; tarsus, 2.70-3.25. Female. Wing. i:i.;»-14.2S: Uill. 

 9.110-lli.iKt: tarsus. 3.10-;i.20. 



/). Tarsus less than twice as long as middle toe. Form deeiiledly more robust. 



2. B. borealis. Tail rufous in adult, brownish gray banded with blaek. in young; 

 outer webs of primaries without light spotting. Ailiilt. Lower parts varying 

 from entirely white, with a few dusky markings on abdomen and Hanks, to dusky, 

 with or without a rufous breast-patch. Tail rufous, usually with a single subter- 

 minal black bar. sometimes with indications of other bars, rarely without any 

 bar. Yvuiig. Lower parts white, more or less varied with dusky, especially across 

 abdomen, or almost wholly dusky (in some western specimens). Tail brownish 

 gray, crossed by about !• narrow bamls of blai-klsh. Male. Wing. 1:1.50-16. .W; lull, 

 X.5l)-10.00: tarsus. 2.IO-;i.2i>. Female. Wing. 15.25-17.75; tail.9.5l>-10..';0; tarsus. 3.I5-;i.40. 

 ;i. B. harlani. Siniilar in form to 7i. ^orcn/ix. but lateral toes nearly eiiunl. and 

 tibial plumes better developed, reaching to or beyond the base of the toes. Pro- 

 vailing color blackish, the bases of the feathers pure white, .itiult. Tall con- 

 fusedly mottled with grayish, dusky and white, in variable relative amount, often 

 nilxod with rufous, and erossed by a subterminal bar or narrow band of dusky. 

 VoHiifl. Tall crossed by 7-9 bands of grayish brown and ihisky. the two colors 

 about equal In width. Male. Wing. 14.25-15.00; tail. 8.W-10.tHI; tarsus. 2.7.5-3.25. 

 Female. Wing. 1,').75-1(!.20; tail. 9.10-10.00; tarsus. 2.90-3.50. 



B. Only thnv outer primaries with inner \vebs emarginated. 



.'■. B. swainsoni. Size large (wing more than 12 inches), the tipsoftheclosedwlngs 

 reaching nearly or iiuite to the end of the tail. Tall (of both adults and young) 

 grayish brown (sometimes with a hoary cast), erossed by 9 or more narrow- 

 dusky bands.theselessdistinct biusally. Upper parts nearly uniform duskybrown. 

 yiirmal plumaoe. Lower parts whitish (or light colored), with a distinctly dellncd 

 breast-patch, rufous In the male, brown In the female. Melniiinlir plumage. 

 Lower parts entirely dusky, or with dusky prevailing, with or without ailmix- 

 ture of rufous. Ynuug. Above brownish black, with ochraceous edgings to fentli- 

 ers; beneath Hue oehraeeous.more or less marked with tear-shaped spots of 



