. ▁Bro oks , ▁R . ▁E . ▁Wood , ▁and ▁R . ▁B . ▁D ahl gren . ▁ 1 9 6 7 . ▁Sex ing ▁of ▁pra irie ▁gr ouse ▁by ▁crown ▁fe ather ▁patterns . ▁Journal ▁of ▁Wild life ▁Management . ▁ 3 1 : 7 6 4 - 7 6 9 . ▁ ▁Hoff man , ▁R . W .; ▁& ▁Thomas , ▁A . E . ▁( 1 7 ▁August ▁ 2 0 0 7 ): ▁Columb ian ▁Sh arp - ta iled ▁Gr ouse ▁( T ym pan uch us ▁ph as ian ell us ▁col umb ian us ): ▁a ▁technical ▁conservation ▁assess ment . ▁[ On line ]. ▁US DA ▁Forest ▁Service , ▁Rock y ▁Mountain ▁Region . ▁ 1 3 2 ▁pp . ▁PDF ▁full text ▁Retrieved ▁ 2 0 0 8 - 1 2 - 2 8 . ▁Joh ns g ard , ▁P . A . ▁ 1 9 7 3 . ▁Sh arp - ta iled ▁Gr ouse . ▁pp .   3 0 0 – 3 1 9 ▁in ▁Gr ouse ▁and ▁Qu ails ▁of ▁North ▁America . ▁The ▁University ▁of ▁Neb r aska ▁Lincoln ▁press . ▁Joh ns g ard , ▁P . A . 2 0 0 2 . ▁Da wn ▁Dan cers ▁on ▁Dun ▁Gr ass ▁The ▁sharp - ta iled ▁Gr ouse ▁and ▁the ▁Northern ▁Pra i ries ▁and ▁S hr ub lands . ▁P ages ▁ 8 1 – 1 0 3 ▁in ▁Gr ass