ABSTRACT

The common dormouse is the more rare terrestrial mammal living in Sicily. An inventory of its presence in woodlands of the Madonie Regional Park has been carried out by the use of artificial nest-boxes. From September 95 to September 98, six sample areas were monitored monthly, resulting in 3468 checks and 525 records of animals. Relative frequency, by the DAT index, proved to be higher in mixed deciduous oak woodlands (25 and 30.5%) of the colchic belt and in the mixed hazel groves (10.6%), than in the pure stands of beech (4.3%) or ilex (0.7%). The absence of a dense and rich in species understorey is one of the major factors limiting the species' abundance. Density per hectare proved also to be higher in the mixed deciduous wood than in the hazel grove (8.2 vs 4.6 adults). Nest-boxes occupancy is continuous throughout the year and shows two peaks; the first in May-June; the second in November-December, nest-boxes are deserted only during August. The 67% of the checked litters (n = 34) took place from September to December; this latter and November are the peak months of reproduction. The mean litter size was 4.2 (± 1.4; min-max: 1-8), but the spring litter size was smaller than those occurring during fall and winter. Torpor is lacking or very reduced in the studied and occurs just for few days, or weeks during cold weather perturbations and snow. The average body weight is around 20 grams, and is steady all along the year, winter fattening being absent. The Sicilian population of common dormouse is at the southern limit of the species' range, but is well adapted to the Mediterranean biome, where the dry and hot summer seems the season more difficult to deal with. Reduced torpor, steady body weight, continuous reproduction and the consequent bimodal population cycle are the major features of this adaptative process.