ABSTRACT

The study was conducted in years 1993-1996 in the Białowieża Forest (northeastern Poland) between May and July. 165 nestboxes fixed along a transect (in c. 65 m distance from each other), which were used by Forest Dormice as daily hides, were controlled. Captured animals (n=76) were individually marked. 92% of nestboxes were used during a year by one individual. In 63% of recaptures Forest Dormice were found in the same nestbox as previously. This suggest that the diameter of the home range is c. 65-100 m. The marginal number of cases when one nestbox was occupied by several Forest Dormice indicates that these animals are territorial in the studied part of the year. 10% of animals moved at remarkable distances - 2 km on average. They should be regarded as migrants. Territories are relatively stable from year to year. After the hibernation 47% of animals were encountered in the same nestbox as in the previous year and the most frequently (71%) movements for distances up to 200 m were noted. In a randomly selected season of studies, Forest Dormice occupied c. 35% of nestboxes among all ever inhabited (n=105). 44% of nestboxes were used in only one season. Thus, the population of the Forest Dormouse does not saturate all suitable habitats in the Białowieża Forest. This can be associated with location of the study area at the northwestern border of the species range.