Spatial dynamics of fox squirrels (Sciurus niger) in fragmented landscapes
We examined the spatial dynamics of fox squirrels (Sciurus niger) occupying 12 woodland sites in a predominantly agricultural landscape of west-central Indiana. The 12 sites represented woodlands of varying degrees of isolation and size. Forty-nine adult fox squirrels were fitted with radio collars and monitored from May 1993 through September 1994. No movements of collared adults were observed between wooded sites during the study, although squirrels traveled 200–500 m from woodlots along hedgerows, and 2.6% of observations occurred in agricultural fields. Multiple regression revealed a positive linear relationship between home-range size and woodland size, with larger home ranges in the growing season. Home-range size was not related to woodland isolation, squirrel density, or sex. We found no evidence of spatial interactions between pairs of squirrels (i.e., male–male, male–female, female–female) at resolutions of 20, 40, or 100 m. Excursions beyond a core area were of relatively greater magnitude for squirrels occupying continuous forest. Agriculturally induced fragmentation of forests appears to restrict movements of adult fox squirrels, despite the well-documented ability of the species to persist in such a landscape.