Historic and current distribution of the forest dormouse (Dryomys nitedula) in Austria

The Forest Dormouse ( Dryomys nitedula ) shows a large albeit heavily fragmented distribution across Europe and Asia. Austrian populations belong to the distinct subspecies D. nitedula intermedius, which has only been found in the eastern Alpine region. Information on the occurrence of this subspecies is very rare and at the outset of this study most records dated back several decades. The aim of this research was to collect and critically analyse all published records on D.n.intermedius in Austria and revise its distribution range combining data research, field work and citizen science. The species’ current distribution was assessed via a nest box study and a nationwide citizen science program. A total of 168 records could be obtained, with 78 recent detections (2020-2024) from the project. Citizen science proved to be a highly efficient method to obtain records, whereas next box occupancy was low even in the core area of the species’ confirmed range. While a suspected decline of D. n. intermedius in the Alpine foothills was reaffirmed, new occurrences in the south could be documented. The main area of the current Austrian forest dormouse distribution is located in the Central Alps.