They don’t live forever: How life history data and encounter probability help to assess success of Muscardinus avellanarius translocations (Rodentia: Gliridae)

Abstract

Abstract The hazel dormouse (Muscardinus avellanarius) is a European Protected Species and for this reason, hazel dormice are protected from deliberate killing, injury or disturbance and its sites and resting places are also protected. During development projects impacts on hazel dormouse individuals and populations should be avoided. If avoidance is not possible measures of mitigation and compensation have to be implemented. In many cases the only suitable measure to prevent disturbance, killing or injury of individuals is the translocation of hazel dormice to another suitable habitat. The success of translocations has so far been rarely documented. To assess the success of translocations, the natural mortality of hazel dormice has to be considered as well as the likelihood of finding specific individuals during the proposed action. How these data affect the assessment of translocation success is calculated based on published data on seasonal survival rates of different cohorts and of unpublished monthly encounter probabilities of a population of marked animals. Depending on the time between the translocation event and the subsequent monitoring controls the number of hazel dormice likely to be alive can be low. For this reason, success cannot be evaluated with our method if the sample size is too small.