Habitat preferences of edible dormouse,Glis glis italicus: implications for the management of arboreal mammals in Mediterranean forests

Abstract

Research on arboreal mammals living in Mediterranean forests is poor. Molecular research assessed the existence of an evolutionary significant unit in the edible dormouse populations living in south Italy, Sicily and Sardinia, and we decided to investigate the environmental factors capable of explaining its occurrence and abundance in Sicily, for a better management of these populations. We assessed the species habitat preferences by setting 25 large and 25 small nestboxes in five sample areas along an altitudinal gradient of the Madonie Range, and recorded habitat variables, food availability, and demographic data for two years. To obtain synthetic descriptors of the dormice habitat requirements, we extracted uncorrelated linear combinations of original variables by Principal Component Analysis; then we modelled habitat preferences of dormice by Generalized Linear Models, and selected the best models by Akaike's information criterion and model averaging. Dormice abundances varied markedly between the two years of study. Population peaked and reproduced in 2010, a masting year of oaks and beeches. In the following non-masting year, a much lower number of adults and yearlings used nestboxes, without any sign of reproduction. In both years we found a significant effect of altitudinal vegetation belt. Dormice seem to prefer mixed broad-leaved and evergreen (cork, holm) oak forests below 800-1300 m a.s.l, to beech forests at higher altitude, and avoid coniferous plantations. Inside these woodlands they seem to prefer monotypic and mature oak-stands with dense canopies. Large nestboxes are more preferred than small ones only during reproductive years. Protection of large and mature woodland from wildfires and forestry management caring the retention of significant elements like old trees, logs and litter mounds are necessary to maintain the habitat of edible dormouse in Southern Mediterranean forests. Artificial nestboxes are a viable device to help population restocking in degraded forests.