Analysis of the hazel dormouse, Muscardinus avellanarius, distribution in a Mediterranean fragmented woodland

Abstract

The hazel dormouse, Muscardinus avellanarius, distribution was investigated in a fragmented woodland of central Italy. In order to understand the effects of habitat fragmentation and forest structure on this species its presence‐absence was analysed in 38 forest fragments, in relation to several parameters, i.e., the wood‐lot area and isolation, floristic diversity, tree diameter and height, number of vegetation strata, and vegetation density. The human activities practised in the various forest fragments, such as forest management and grazing by domestic cattle, were also recorded. The surveys were conducted by using two different methods, i.e., the hair‐tubing technique, and the searching for hazel dormouse nests. Hair‐tubing confirmed hazel dormouse presence in all woodlots positively checked by nest searching, while this technique failed to detect the species in nine woodlots positively surveyed by using hair‐tubes. Our results indicated that in grazed woodlots M. avellanarius was likely to be absent, while no evidence was found about its preference for a given type of forest management, although its incidence was higher in coppices than in high forests. However, in the four more intensively managed woodlots, the hazel dormouse was always absent, while it was present in the three remaining high forests. Woodlots with more diversified undergrowth were more favourable to the species, while in forest fragments with conspicuous mean tree diameter and height it was likely to be absent. Woodlots well connected with hedgerows were associated with higher probabilities in finding the hazel dormouse, while no evident correlation between its presence and woodlot area was found.