Some songbirds learn to sing by listening to other birds. Some other animals can learn to copy sounds. But what does that tell us about human speech? Sonja Vernes from the Max Planck Institute for Psycholinguistics in Nijmegen is lead editor of a special issue of the Philosophical Transactions of the Royal Society B on vocal learning in animals and humans, bringing together research on animals ranging from seals and bats to birds and humans.