Habitat preferences of the mountain population of the endangered beetle Carabus variolosus ssp. variolosus indicate its vulnerability to climate change

The general habitat requirements of many common ground beetle species are known, but which specific environmental factors play a crucial role in their distribution remain uncertain. Such detailed knowledge is of key significance in the context of identifying changes and threats to a particular species and enables rational decisions to be taken regarding its conservation. The aim of this study is to describe habitat preferences of the mountain population of the endangered beetle Carabus variolosus. Results show that soil moisture is the key factor of C. variolosus occurrence. The probability of presence of this species increases with soil moisture and this is the only factor that is significant for the species as a whole and for males and females separately. Therefore, decrease in soil moisture conditions, observed in recent years, can be critical to the survival of this species. Other potential predictors of its occurrence are vegetation cover, vegetation height and number of trees. However, they are informative only when combined with soil moisture and the effects of these variables on the species occurrence are much weaker. Results also show significant sexual differences in habitat selection, as females habitat preferences are more restrictive than those of males.