Rise and fall of a Eurasian lynx (Lynx lynx) stepping-stone population in central Germany

Abstract

After having been extinct for approximately 200 years, the Eurasian lynx (Lynx lynx) is currently being reintroduced in several European countries. However, it still occurs in several local, isolated populations. Given the patchy distribution of its forest habitat within a human-dominated landscape, the formation of population stepping-stones, i.e., small lynx occurrences between source populations, has been suggested an important mechanism for the expansion of lynx in central Europe. We studied the population history of such a stepping-stone population, which emerged approximately 60 km southwest of a larger reintroduced population in central Germany. We also examined migrations of lynx between the source population and the stepping-stone. At the beginning of our study in autumn 2014, our study population consisted of a minimum number of six resident individuals of both sexes that successfully reproduced in the area. However, over the course of only a single year, this subpopulation declined to only a single resident male as a consequence of death and emigration. In the 4 years after this decline, the subpopulation did not recover due to the absence of female dispersal into the area. Our study illustrates the vulnerability of small, isolated populations to stochastic demographic events and suggests that constraints on female dispersal are a major reason for the slow expansion of lynx in central Europe. To promote the expansion of lynx, active population management will be required, involving the translocation of females to reinforce existing stepping-stone populations or to create new ones.