▁The ▁O live ▁grass ▁mouse ▁ ▁is ▁a ▁host ▁of ▁the ▁A can th oce phal an ▁int est inal ▁par as ite ▁Mon il iform is ▁am ini . ▁ ▁Out break s ▁of ▁this ▁species ▁sometimes ▁occur . ▁In ▁ 1 9 9 0 , ▁the ▁b am bo o ▁Ch us que a ▁val div i ensis ▁had ▁a ▁mass ▁seed ing ▁phenomen on ▁in ▁which ▁over ▁a ▁million ▁hect ares ▁of ▁this ▁b am bo o ▁in ▁southern ▁Chile ▁flow ered ▁at ▁the ▁same ▁time ▁and ▁then ▁died . ▁The ▁enorm ous ▁quantities ▁of ▁se eds ▁were ▁followed ▁by ▁a ▁mass ▁population ▁increase ▁of ▁the ▁rice ▁rat ▁O lig ory z om ys ▁long ica ud atus ▁and ▁to ▁a ▁less er ▁extent , ▁of ▁the ▁o live ▁grass ▁mouse . ▁In cre ases ▁in ▁rod ent ▁numbers ▁can ▁be ▁attributed ▁to ▁a ▁greater ▁f ec und ity , ▁a ▁higher ▁surv ival ▁rate ▁of ▁ju ven iles ▁and ▁an ▁extension ▁in ▁the ▁bre eding ▁season . ▁Since ▁many ▁of ▁the ▁b am bo o ▁se eds ▁were ▁retained ▁within ▁the ▁flow ering ▁sp ike lets ▁for ▁a ▁year , ▁further ▁rod ent ▁population ▁pe aks ▁occurred ▁in ▁subsequent ▁years . ▁ ▁Status ▁A . ▁ol iv ace us ▁is ▁a ▁common ▁species ▁with ▁a ▁pres umed ▁large ▁population . ▁It ▁has ▁a ▁wide ▁range ▁and ▁is ▁present ▁in ▁several ▁protected ▁areas . ▁It ▁seems ▁toler ant ▁of ▁habitat ▁de grad ation ▁and ▁no ▁particular ▁thre ats ▁have ▁been