Protecting local populations of Hazel Dormice (Muscardinus avellanarius) by translocation: a long-term case study from North Rhine-Westphalia (Germany)

Abstract

As part of the mitigation measures adopted in the context of preparatory clearcutting for surface mining, Hazel Dormice have been translocated since 2011. The project is situated in the geographical region of Lower Rhine Basin (North Rhine-Westphalia, Germany). To date, Hazel Dormice have been translocated from an old-growth deciduous forest to four other sites. Three release sites are re-cultivation areas which were planted with trees and shrubs roughly 10 to 30 years ago. The other release site is an old-growth deciduous forest with a well-developed understory. Nest boxes were placed in the source forest and checked between April and October. Any dormice that were found were individually marked and released, inside their nest boxes, at the new sites. Two or three additional nest boxes were placed within the surroundings of each translocated box. Between 2011 and 2018 we translocated 1,840 individuals. We verify the success of translocation by monitoring the release sites in June and September of the first, second, fifth and eighth year after translocation. Additionally, a sample of 200 nest boxes were checked each month between April and October for five years. Finally, we examined groups of nest boxes shortly after translocation to gather information on the translocated animals immediately after release. Individual records reveals that translocation can be a successful conservation measure to secure local populations if their former habitat is damaged.