▁conservation ▁efforts ▁for ▁the ▁water ▁vo le ▁- ▁an ▁animal ▁that ▁has ▁decl ined ▁by ▁over ▁ 9 0 % ▁in ▁Britain ▁since ▁the ▁ 1 9 8 0 s . ▁The ▁National ▁Water ▁V ole ▁Mon itor ing ▁Program me ▁is ▁the ▁first ▁on going ▁monitoring ▁scheme ▁for ▁this ▁species ▁in ▁the ▁UK ▁and ▁a ims ▁to ▁bring ▁together ▁data ▁from ▁several ▁hundred ▁sites ▁to ▁allow ▁the ▁status ▁of ▁the ▁species ▁to ▁be ▁ass essed ▁year - on - year . ▁ ▁Camp aign s ▁ ▁European ▁h edge h og ▁ ▁In ▁ 2 0 1 1 ▁P T ES , ▁in ▁partners hip ▁with ▁the ▁British ▁H edge h og ▁Pres ervation ▁Society ▁( B HP S ), ▁launched ▁a ▁national ▁campaign ▁to ▁con serve ▁the ▁h edge h og , ▁a ▁m amm al ▁that ▁has ▁decl ined ▁in ▁Britain ▁by ▁at ▁least ▁ 2 5 % ▁since ▁the ▁year ▁ 2 0 0 1 .[ 1 0 ] ▁The ▁H edge h og ▁Street ▁campaign ▁has ▁inspired ▁thousands ▁of ▁people ▁to ▁make ▁their ▁gard ens ▁h edge h og - friend ly ▁and ▁eng age ▁with ▁their ▁neighb ours ▁to ▁make ▁their ▁entire ▁streets ▁accessible ▁to ▁h edge h ogs , ▁who ▁des per ately ▁need ▁our ▁gard ens ▁to ▁surv ive . ▁[ 1 1 ] ▁ ▁As ▁part ▁of ▁the ▁joint ▁campaign , ▁P T ES ▁coordinates ▁the ▁European ▁H edge h og ▁Research ▁Group ▁and ▁conven es ▁a ▁ste ering ▁group ▁for ▁the ▁species ,