Damage by Grey Squirrels I. Bark-stripping correlates and treatment.

Abstract

In 184 site-year records of damage by grey squirrels, hand-sized or larger patches of bark were always removed when there were more than 0.5 young squirrels/ha, and on 26 per cent of occasions when sap volume exceeded 0.3 cu cm/sq cm of bark removed but only 6 per cent with less sap, Tree seeds enhanced squirrel breeding: large bark patches were stripped at only 33 per cent of sites without seed-bearing trees but at 72 per cent with one to three seed-bearing species. Such stripping occurred at only 8 per cent of sites with >50 per cent groundcover. With Warfarin introduced after pre-baiting for 10 days, one hopper/2 ha removed all squirrels in three to four weeks.