Nest site preference by common dormouse (Muscardinus avellanarius) in two different habitat types of Central Italy

Nest site preference of common dormouse was studied in two different habitat types of central Italy: a mesophilous deciduous forest dominated by Fagus sylvatica, and a thermophilous deciduous oak wood with Quercus cerris and Q. pubescens. In each site, 50 nest boxes were fixed to trees and monitored monthly for two years (May 1998–April 2000). Moreover, in both study sites, 19 habitat variables were measured within a 3-m radius circular plots centred on each nest box. We hypothesised that specific habitat features may induce common dormice to choose a particular site for nesting. Therefore, we compared habitat variables, recorded at the neighbourhood of either occupied or unoccupied nest boxes, in order to identify the importance of factors in nest site preference. In both beech and oak woodlands, the choice of nest site was affected by understorey vegetation structure rather than species diversity. In particular, the common dormouse prefers sites with high understorey density probably for the presence of route-ways through branches and visual protection from predators. Keywords: Gliridae, habitat choice, deciduous forests, nest boxes