BIRDS OF NORTH AND MIDDLE AMERICA 155 



KEY TO THE FORMS OF BONASA UMBEI.LUS (LINNAEUS) 



a. Genera] colorarion more brov^Tiish than grayish. 

 6. Dark-brown ventral barring pronounced. 



c. General coloration verj- dark (chestnut to dark auburn). 

 d. General coloration distincrly brownish with little or no graj-sh cast 

 c. \'ery reddish, back bright argus brown to dark chestnut, tail auburn 



to bay (Olympic Peninsula) Bonasa umbelltis castanea (p. 169) 



cc. Duller and less reddish, back between Prout's brown and Dresden 

 bron-n; rail dull ochracecu;-iiin'D€r (brown phase) (Vancouver Island) . 



Bonasa umbellus brunnescens (p. 170) 



dd. General coloration with more graWsh or duskj- appearance; tail argus 



brown to cinnamon-browTi (w. slopes of Rockj- Mountains, Idaho, to 



ne, \\'ashington) Bonasa umbeHus phaia (brown phase) (p. 17i) 



ct". General coloration lighter (saj-al brown to argus brown). 

 d. Distinctly brownish with Uttle or no grajish cast 



e. Ventral barring darker — cinnamon-brown to dark mummy brown (,;w. 

 Eriush Columbia to nw. Califomia) Bonasa mnbeUus sabini (p. 166) 

 ft'. Ventral barring lighter — dusk\- isabelline to buckthorn brown (Appala- 

 chian Mountains from ne, Pennsyh'ania to Georgia) . 



Bonasa umbellus monticola (p. 163) 

 dd. Browns mixed with some gray. 



e. Blackish areas of uj-perfarts more pronounced; broTvn jarts darker and 

 less rufescent — ci nnamon-brown tc dark Prout's brown (n. Xew 

 England, Xova Scotia, w. to s. Ontario). 



Bonasa umbelltis togata (p. 171) 

 ee. Blackish areas of upperjorts less well developed, brown areas paler 

 and more rufescent — Mikado brown to snuff brown (nc. British 

 Colvmibia s. to ne. Oregon) . 



Bonasa umbellus affinis (brown phase) (p. 175) 

 bb. Light brown, barring less pronoimced, 



L. General coloration darker, head and neck with little if any grayish suf- 

 fusion, tail (brown piiase) nearly hazel ( s. Xew England, e. Xew York, 



b. to District of Colimibia) Bonasa umbeUus umb^us (p. 156) 



tj. General coloration paler, head and neck with pale graj-ish sumision, tail 

 (brown phase) nearly ochraceous-tawnj- (sw. Michigan s. to c. Arkansas). 



Bonasa umbellus mediana (p. 161) 

 aj- General coloration more graj^ish than brownish. 

 b. Definitely gray, with Uttle or no b rownish wash, 

 t. Verj' pale (smoke graj' to pale neutral gray). 

 d. Tarsus imfeathered" for one-quarter its length or less; more white in 

 "tperfar;s (w. Alaska to n. Alberta). 



Bonasa umbellus yukonensis (p. 1S2) 

 dd. Tarsus unfeathered" for not less than half its length; less white in 

 upperpans (c. Utah, se. Idaho, to ne. North Dakota). 



Bonasa tsnbellus incana (p. 179) 

 cc. Darker (moiis; gray to light grayish oUve) (w. slofe of Rocky Mountains, 

 Idaho, to ne. Washington) . .Bonasa umbellus phaia (gray phase) (p. 1"S) 

 bb. Gray mixed with considerable browTL 



i,-. Tarsus unfeathered for more than half its length (nc. British Colimibia 

 to ne. Oregon) Bonasa umbellus affinis (gray phase) (p. 175) 



" Point of insertioa of feathers c n outside of tarsus to junction of tarsus with 

 middle toe is measurement for unfeathered tarsus. 



