Gray herons hunt near a Berlin subway station, foxes nap in the sun at Cologne's Klingelpützpark, and endangered grey-headed flying foxes hang in the trees near the Sydney Opera House. The wilderness is unmistakably pushing into the cities, with once-shy animal species becoming part of urban nature. Amidst stone, concrete, and asphalt, there is an astonishing diversity of species. Nowhere can so many native bird species (more than 150) be observed in such a small area as in Berlin – certainly not in the much-praised but heavily utilized open countryside. How can this be explained? Have our cities blossomed into oases while the surrounding countryside deteriorates into agricultural wasteland? What does this diversity say about the quality of habitats in both urban and rural areas? What must animals possess and how must they adapt to survive in our neighborhoods?.