ation . ▁ ▁One ▁habitat ▁change ▁seen ▁by ▁H amer st rom ▁and ▁H amer st rom ▁( 1 9 5 1 ), ▁was ▁gr ouse ▁would ▁select ▁large ▁snow ▁banks ▁to ▁bur row ▁into , ▁to ▁keep ▁warm ▁during ▁cold ▁night s . ▁The ▁use ▁of ▁bur rows ▁was ▁also ▁noted ▁by ▁Gr at son ▁( 1 9 8 8 ). ▁ ▁Hab itat ▁fragment ation ▁Hab itat ▁fragment ation ▁has ▁been ▁one ▁of ▁factors ▁driving ▁the ▁decl ine ▁of ▁all ▁sub species ▁of ▁sharp - ta iled ▁gr ouse ▁across ▁its ▁entire ▁range ▁throughout ▁North ▁America ▁( Sil vy ▁and ▁H agen ▁ 2 0 0 4 ). ▁The ▁type ▁of ▁habitat ▁fragment ation ▁var ies ▁from ▁e colog ical ▁succession , ▁as ▁shr ub / gr ass land ▁areas ▁transition ▁into ▁for ested ▁areas . ▁Fire ▁supp ression , ▁tree ▁plant ings , ▁limit ing ▁logging ▁practices , ▁and ▁an ▁increase ▁of ▁invas ive ▁wo ody ▁species ▁have ▁also ▁led ▁to ▁habitat ▁fragment ation . ▁The ▁largest ▁contrib utor ▁to ▁habitat ▁fragment ation ▁has ▁been ▁the ▁agricult ure ▁industry . ▁ ▁The ▁Hom est ead ▁Act ▁ 1 8 6 2 ▁opened ▁up ▁great ▁exp ans es ▁of ▁vir gin ▁pra irie ▁in ▁the ▁west ▁to ▁early ▁sett lers . ▁By ▁ 1 9 0 5 ▁about ▁ 4 1 ▁million ▁hect ares ▁of ▁the ▁west ▁had ▁been ▁hom est ead ed ▁( O ls en ▁ 1 9 9 7 ). ▁Much ▁of ▁this ▁land ▁was ▁in ▁semi -