‘ALEX TAUGHT ME to believe that his little bird brain was conscious in some manner; that is, capable of intention. By extrapolation, Alex taught me that we live in a world populated by thinking, conscious creatures. Not human thinking. Not human consciousness. But not mindless automatons sleepwalking through their lives, either.’ So Irene Pepperberg wrote about her African grey parrot Alex, the most famous parrot in history. Alex died in 2007, after working with Pepperberg in her laboratory for thirty years. He was already well known, but when he died he got obituaries in the New York Times andTime.

When Pepperberg began working with Alex, she had no idea that he was going to help overturn human understanding of the capabilities of animals. Alex showed what fond pet owners have long suspected: there is a lot going on inside an animal, and we can only guess the half of it. For hundreds of years, animals have been viewed as less important, less feeling, less cognisant. For most of the twentieth century, scientists derided the notion of animal consciousness: dumb animals – not able to speak, not able to think. Language was seen as the magic attribute that separated humans from brutes. But over the past thirty or forty years, scientists who have been working with non-human animals have been gradually uncovering the special talents and means of communications of all sorts of animals, from bees to octopi, dolphins to elephants.