Since wolves returned to Germany 20 years ago, they have spread quickly in many parts of the country. The rapid increase in the number of wolves was due to high survival and reproduction rates in areas with favourable environmental conditions. This is the result of an analysis carried out by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in collaboration with the LUPUS Institute, the Federal Agency for Nature Conservation (BfN), and the Senckenberg Center for Wildlife Genetics. The probability of survival for wolves during the period analysed was higher than anywhere else in the world.