Harvest mice Micromys minutus and common dormice Muscardinus avellanarius live sympatric in woodland habitat

摘要

In an overgrown clearing, which occupied an area of 5 ha within mixed spruce-deciduous forest, 106 and 20 nests of the harvest mouse Micromys minutus (Pallas, 1771) and 81 and 59 nests of the common dormouse Muscardinus avellanarius (Linnaeus, 1758) were recorded in the fourth and fifth years after clear-felling, respectively. The highest densities of nests of M. minutus and M. avellanarius were 46 nests/ha and 39 nests/ha, respectively, in two different plots. The affinity between M. minutus and M. avellanarius was negative in overgrown clearings according to the distribution of their nests. Such a result was expected because M. minutus and M. avellanarius used different nest supporting plants: M. minutus used tall grasses, while M. avellanarius used young trees and shrubs. However, no positive relationship was found between the number of nests of M. minutus and cover of grass vegetation in plots with the highest density of nests of M. minutus. Most nests of M. minutus were situated in areas covered by young trees among which tall grasses, mainly Calamagrostis epigeios, grew, often on the borders with the areas covered by grass vegetation. The successionary stage when woody vegetation reached 4-5 years old did not choke grass vegetation yet was favourable for both M. minutus and M. avellanarius in overgrowing clearings.