468 BIRDS OF ILLINOIS. 



Ailnll iitalf (five Hpi'oimenii from Nfviulii.i'ollcnit'd by tlio author). Tolnl l«>nBth.'J1.8t>- 

 2».n(i lni-lii'»: nxlcnt. 4'.i.(K)-M.(KI: w>-l»rlil, 2-3 iiouiulx. Bill dull tilnrW tfrmlnully, 

 licht IiIuIhIi liiiKjilly; ccri' mill rli'lus »;rc rninti yi-llow; IrlB deep liii/.>'llii8om<' K|ii->'lnii'nH. 

 llKlit yi'lliiw Id olliiTs.in two HpucimoiiK yellow on upper portion iiuil brown below; loitn 

 und feet liulil yell.iw: "'laws blilek. 



Ailiilt fi-iiiale (llvo speeimons from Neviidii, colleoted by tlio author). Total lenjrtli. 

 ai.lH>-i4.(H)lnehe«; extent. M.(i(i-57. On; weiehl.-'M pnuiidn. Fro»li eolorH ii« In the above- 

 nienlinned nialew. (Iris Naiilen yellow in one very blaek nielanlHlie inilividual, deep 

 ha/.el in II rufous-breanleil niohinititie specimen, and hazel in three liKlit-eolonMl ex- 

 amples.)* 



The yoiinp bird of this wostoni style is usually as ilifTfretit from 

 that of the eastern as is the adult, and the essential diiTerences 

 are about the same, — i. e. darker colors, or a predominance, or 

 rather, increase in size, of the dark markings. The numerous heavy 

 transverse spots on the tibiie constitute a marked feature of the 

 averafie young valnrun, as compared with the almost, or sometimes 

 entirely, immaculate white of those in hoirdUn. 



'■■ krideri 



SuDKP. Chab. A'liill. Similar to 'xinn /is. Ii\it lnie'iitli .■.•lllMlll■'ll^i pure wlilte, with- 

 out rufous tince.and witliout ilii^tinet spots across the alidomen, or hi'ki net hem entirely; 

 above miiidi li(thter, the brown, liirht rufous, and while beine about e<iual in amount. 

 Upper tail-coverts immaculate white; tail pale rufous, tho shafts pure white, and the 

 webs mixed with white alone their edKcs. its amount incrcnsine toward the base; no 

 trace of a dusky subti'rniinal bar. or el.se only imlicated by badly detlned spot?. 



"Vouug. Bifterini,' from that of var. (/oipu'is in the immai'ulati', snowy white lower 

 ports, nearly equal extent of the white and dusky on the upper parts.and whitish cast of 

 the tail. 



This tine bird, although far less numerous than the Red- 

 shouldered Hawk (B. liiu'dtiis) is yet very ccmnnon in most por- 

 tions of the country. According to Mr. Horace A. King (in Onii- 

 tUoloijUt (iikI Ordon'ixt, Vol. IX., .Tuly, 1881, p. 81), "One of the com- 

 monest birds of prey to be found in northern Illinois, is the Red- 

 tailed Hawk {Biiteo horeaUs). A person will meet with them in nil 

 sorts of places, but they are most eonnuon in the vicinity of heavy 

 timber. In driving througli the country one will see them perched 

 upon liiil fences, trees by the way-side, sitting on the ground in 

 stubble or pasture fields, or soaring over fields in search of their 

 prey. When on one of his foraging expeditions, the Red-tail, on 

 sighting his prey, will remain at the same place in the air liy a 

 continual flapping of the wings, when at tlie proper time he will 

 dive swiftly and silently iijion it." 



•The color of the iris in lliis spccii's (any race) is very inconstant. In the fully adult 

 It may bi' cither deep hazel. liehl liazi'l.liirht yellow. or partly brown and yellow: if the 

 lalter.thc yellow usually occupies the upper portion of the iris. In immature birds the 

 Iris may be either ciciir lieht yellow.pale brown, or liglit grayish; the llrst, however, ap- 

 pours to be the usual color. 



