IVth International Conference on Dormice (Rodentia, Gliridae)

13 - 16 September 1999 EDİRNE - TURKEY

Trakya University Department of Biology

ECOLOGY AND DISTRIBUTION OF MUSCARDINUS AVELLANARIUS IN WOODLANDS OF SICILY

*Department of Anımal Bıology Vıa Archırafı, 18 - 90123 Palermo (I), Italy E-mail: mausar@unipa

** Instıtute of Agronomıc Entomology, Vıale Delle Scıenze - 90134 Palermo, Italy

The common dormouse in one of the rarest mammals living in Sicily, strongly localized in the north-eastern mountain ridge. A survey on its presence and relative density in different woodlands of the Madonie Regional Park has been carried out by the use of nest-boxes. During three years (from september 95 to september 98) seven sample areas were monthly monitored. Relative frequence, by the DAT index (n individuals/nchecks*nboxes), proved to be higher in mixed deciduous woodlands (DAT = 25 and 30.5%) of the colchic belt (Quercus petraea, Ilex aquifolium, Acer spp, Castanea sativa), than in pure stands of Fagus sylvatica (DAT = 4.3%) or Quercus ilex (DAT = 0.7%). An initial good frequence in mixed hazel groves (DAT = 10.6%) later dropped down probably by human disturbance. The absence of a rich understory (cutted and/or grazed) seems one of the major factor limiting the abundance of the species. Density, run in two areas by CMR analysis restricted to territorial individuals, proved also to be higher in the mixed deciduous wood than in the hazel grove (8.2 vs 4.6 adults/ha).

The frequence of nest-boxes occupancy shows typically two peaks, the first during may-june; the second one during november and december. Nest-boxes are generally deserted in summer. The 67% of the checked births (n =34) took place from september to december; november and december being the peak months of reproduction. The productivity was on average of 4.2 pups (± 1.4; min-max: 1-8), and the spring births are smaller than those occurred during fall and winter (3.6 vs 4.0-5.0). Food availability is higher in these last seasons.

Torpor is lacking or very reduced in the studied population (4.4% of 525 handled animals) and occurrs just for few days (or weeks) during winter cold perturbations and snow, mostly in March. It seems also dependent from the individual physiological conditions; since we have once found a female with pups and in the close by nest-box another individual in torpor.

The sicilian population of common dormouse is at the southern limit of the species’ distribution range, but seems to be well adapted to mediterranean climate and ecosystem. Reduced torpor, prolonged reproduction throughout the year and a bimodal population cycle seems the major results of this process. Dry and hot summer instead of mild winter seems the season more difficult to deal with. Forestry management and summer fires are among the greatest threats for the species, increasing habitat destruction and fragmentation.