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uni'wissen 01-2014_ENG

Wildlife crossing over an autobahn: Corridors between different ranges of the same species enable genetic exchange. Photo: picsxl/Fotolia If you’re lucky, you might chance upon such shy animals as the wood grouse, the black grouse, or the dormouse on a hike through the German countryside. However, the populations of these wild animals have grown smaller and smaller in recent years. The main reason is the loss of suit- able habitats, owing among other things to the intensification of agriculture and the spread of housing developments. The natural environments of these animals are being broken up, their small populations isolated. Dr. Gernot Segelbacher and his assistants at the Department of Wildlife Ecology and Wildlife Management of the University of Freiburg are investigating the impact of these trends on biodiversity. In one project, the team studied dormouse populations near Tübingen and Ulm. Segelbacher and his colleagues from the Universities of Hohenheim, Tübingen, and Aarhus, Denmark, investigated whether there is still genetic exchange between the individual populations, even though the habitat has been broken up into several sepa- rate areas. The research site near Tübingen was a large unbroken forest, while the one near Ulm consisted of four forest fragments. The researchers marked a total of 380 dormice with microchips between 2001 and 2009. In addition, they took skin samples to determine the genetic fingerprints of the rodents and compared them to each other. Comparing Current and Historical Samples The results of the study confirmed the research- ers’ main hypothesis: In the unbroken forest there was an exchange of genes between the individual populations, whereas the dormice in the site near Ulm were no longer able to overcome the distance between the fragmented ranges and were more or less isolated. “The result is an increasing loss of genetic variability, leading ultimately to in- breeding, which will make it practically impossible for the dormouse to survive in the forest fragments analyzed in the study in the long term,” says Segelbacher. Scientific findings like these provide important information for sustainable conservation and sensible land-use planning. They indicate where it is necessary to leave corridors between the ranges of endangered species and where wildlife crossings would be most useful. The science of conservation genetics now pro- vides noninvasive procedures that allow research- ers to take samples from animals without catching them. Segelbacher has developed a method of this kind for indigenous birds like the wood grouse or “The result is an increasing loss of genetic variability, leading ultimately to inbreeding.” 25