▁non - wood ▁forest ▁products , ▁and ▁numerous ▁forest ▁products . ▁The ▁park ▁is ▁also ▁used ▁as ▁past ure land ▁for ▁over ▁six ▁months ▁each ▁year ▁by ▁a ▁huge ▁number ▁of ▁mig rat ory ▁cattle ▁and ▁y ak ▁her ders . ▁ ▁Winter ▁gra zing ▁grounds ▁ ▁In ▁J ig me ▁Sing ye ▁Wang ch uck ▁National ▁Park , ▁the ▁winter ▁gra zing ▁grounds ▁are ▁found ▁in ▁tropical ▁and ▁sub - t rop ical ▁regions . ▁Such ▁regions ▁are ▁generally ▁too ▁hot ▁to ▁res ide ▁in ▁the ▁summer ▁and ▁the ▁for ests ▁and ▁me adows ▁are ▁inf ested ▁with ▁divers ity ▁of ▁we eds . ▁The ▁rivers ▁sw ell ▁too ▁big ▁that ▁crossing ▁from ▁one ▁valley ▁to ▁another ▁is ▁impossible ▁during ▁sum mers ▁in ▁such ▁areas . ▁These ▁areas ▁are ▁best ▁su ited ▁for ▁gra zing ▁in ▁winter ▁when ▁rivers ▁are ▁shall ow ▁and ▁weather ▁becomes ▁moder ate . ▁ ▁The ▁mig rat ory ▁cattle ▁her ders ▁from ▁Ch um ey ▁in ▁B um th ang ▁travel ▁to ▁this ▁low ▁alt itude ▁past ure ▁lands ▁when ▁the ▁climate ▁in ▁the ▁al pine ▁and ▁temper ate ▁becomes ▁un b ear able ▁for ▁the ▁liv est ock . ▁Many ▁mig rat ory ▁her ders ▁from ▁B um th ang ▁own ▁many ▁tract s ▁of ▁t sam dro gs ▁located ▁at ▁different ▁veget ation ▁zones ▁and ▁alt itudes ▁and ▁allow ▁them ▁to ▁migr ate ▁from ▁one ▁place ▁to ▁another ▁with ▁their ▁cattle ▁at ▁different ▁seasons . ▁C attle ▁are ▁moved ▁and ▁rot ated ▁among ▁winter ▁t