NICHE OVERLAP IN SYMPATRIC POPULATIONS OF FOX AND GRAY SQUIRRELS

Resource overlap between fox squirrels (Sciurus niger) and gray squirr els (S. carolinensis) has been reported, but quantitative measures of niche overlap in sympatric populations are unavailable. We examined ni che breadth and niche overlap in habitat and nest characteristics amon g sympatric fox and gray squirrels in central Georgia during 1989-90. We used radiocollared squirrels to locate nests and record locations w ithin forested stands. We classified habitat and nest characteristics into 12 niche dimensions: 2 nest and 10 habitat. On several dimensions , fos squirrels occupied narrower niches relative to pray squirrels. G ray squirrels nested in a greater variety of tree species and selected stands with broader ranges in midstory pine (Pinus spp.) stems per he ctare and overstory species. Intraspecific niche overlap between speci es was greater (P < 0.05) than interspecific overlap on 9 of 12 dimens ions. Intraspecific and interspecific niche overlap did not differ (P > 0.05) on overstory hardwood stems per hectare, overstory pine per he ctare, and midstory tree species. These findings suggest that coexiste nce between fox and gay squirrels was maintained, in part, through nic he partitioning on several dimensions.