Nest-boxes

Many forest dwelling species faces increasing shortage of natural shelters as tree cavities due to a decline of the abundance of large, old trees, eliminated from the forest stands by silviculture. Formation of monocultures, changes in species and age composition of forest stands significantly reduce abundance of such daily roosts, crucial for fitness of many vertebrates. That is why using of substitutes of natural shelters like nest-boxes as a habitat restoration tool increased in last decades. Despite many studies investigating species preferences affecting utilization of nest-boxes, there are almost none comparing natural and artificial-roosts selection at one study site. That is why in our study by using radio-tracking method we investigated the usage of natural and artificial shelters by arboreal rodent-edible dormouse Glis glis in commercial pine forest. Our results show that significant proportion (~50-70%) of utilized roosts were of natural origin, even though artificial shelters were available. Roosts were mostly found in deciduous trees, as birches and oaks, which dormice chose accordingly to the abundance on the study plot. Significantly low selection ratios were found for the most common species on the study plot-Scots pine Pinus sylvestris, probably due to silviculture practices, that for economical reasons promote healthy trees through multiple practices. We also found that the vicinity of roosting sites was char-acterised by dense vegetation of young deciduous trees. Our study indicates that preservation of the mixed forest stands with dense understory layer and old deciduous trees is crucial for arboreal rodents for roosting behavior in managed forests. Moreover, we suggest that maintaining a higher number of tree species that are not managed by foresters (as birch) can improve the functioning of the populations of arboreal rodents more effectively than installing artificial shelters.