New research suggests animals can thrive in human-dominated environments by being expert judges of risk. Alexis Breen from the Max Planck Institute for Evolutionary Anthropology in Leipzig, and Dominik Deffner from the Max Planck Institute for Human Development in Berlin, examined the behaviour of great-tailed grackles, a bird species successfully invading much of urban North America, showing the sex that leads this charge—the dispersing males—shy away from risk, which is a characteristic the researchers show is well-suited to chaotic environments like cities. These findings provide unique insight into how and why animals and humans can coexist.