0 ; ▁Ben k obi ▁et ▁al . ▁ 2 0 0 0 ). ▁This ▁method ▁was ▁used ▁to ▁create ▁a ▁habitat ▁suit ability ▁index ▁based ▁on ▁veget ation ▁visual ▁obst ruction ▁( VO ), ▁r anging ▁from ▁ 0 - 3 0 . 5   cm ▁with ▁a ▁suit ability ▁index ▁rating ▁of ▁ 0 - 1 . 0 ▁( Pro se ▁ 1 9 8 7 ). ▁Studies ▁of ▁nest ing ▁habitat ▁by ▁Pro se ▁et ▁al . ▁( 2 0 0 2 ) ▁in ▁the ▁Neb r aska ▁Sand h ills ▁found ▁that ▁nest ing ▁sharp - ta iled ▁gr ouse ▁selected ▁nest ▁sites ▁with ▁visual ▁obst ruction ▁read ings ▁( V OR ) ▁of ▁more ▁than ▁ 4   cm . ▁Similarly , ▁Cla w son ▁and ▁R ott ella ▁( 1 9 9 8 ) ▁observed ▁that ▁ 5 8 % ▁of ▁n ests ▁( 4 3 2 ▁of ▁ 7 4 1 ) ▁in ▁South western ▁Mont ana ▁were ▁located ▁in ▁sites ▁with ▁an ▁average ▁V OR ▁of ▁ 2 4   cm . ▁The ▁other ▁n ests ▁in ▁this ▁study ▁were ▁located ▁in ▁sites ▁with ▁V OR ’ s ▁of ▁ 1 1 – 1 8   cm . ▁Re e ce ▁et ▁al . ▁( 2 0 0 1 ) ▁observed ▁that ▁sites ▁with ▁a ▁V O ▁of ▁less ▁than ▁ 5   cm ▁near ▁possible ▁nest ing ▁locations ▁indicated ▁a ▁decl ine ▁in ▁quality ▁nest ing ▁habitat ▁as ▁average ▁V O ▁decl ined .