Habitat use and population density of the red squirrel, sciurus vulgaris meridionalis, in the sila grande mountain range (Calabria, South Italy)

Abstract

Counts of squirrel nests (dreys) and vegetation surveys in 32 1-ha census stations were carried out to estimate densities in different forest types and determine habitat selection of the subspecies of red squirrel Sciurus vulgaris meridionalis in the Sila Grande forests, Calabria, South Italy. Dreys were not built randomly, but the majority was constructed at 60–70% of the total height of the nest-tree, pines and oaks being the preferred tree species. Mean drey densities, 2.75/ha, 2.78/ha, and 2.00/ha in, respectively, Cal-abrian black pine forest, beech dominated mixed forest, and chestnut woodlands, did not differ between forest types and extrapolated to estimated squirrel densities ranging from 0.44 to 0.61 squirrels/ha. Variation between stations in a tree species diversity index and in distance from the nearest plot of pine woodland significantly affected variation in drey density: squirrels preferred forest habitats dominated by beech, with also black pine and oak available, or chestnut woodlands that were within the range of one (male) squirrel home range diameter (310 m) of a plot of pine forest (mean drey density 5.4/ha). Fewer dreys were found in deciduous (beech or chestnut) woodland >310 m away from areas with pine forest (1.1 dreys/ha). Hence, the availability, at least in the vicinity of the census station, of pine seeds of the Calabrian black pine as main food resource strongly influenced habitat choice. © 2000 Taylor & Francis Group, LLC.