Summary
Almost 200 years ago, the renowned U.S. naturalist John James Audubon hid a decaying pig carcass under a pile of brush to test vultures’ sense of smell. When the birds overlooked the pig—while one flocked to a nearly odorless stuffed deer skin— he took it as proof that they rely on vision, not smell, to find their food. His experiment cemented a commonly held idea. Despite later evidence that vultures and a few specialized avian hunters use odors after all, the dogma that most birds aren’t attuned to smell endured. Now, that dogma is being eroded by new findings about birds’ behavior and their molecular hardware. One study showed that storks home in on the smell of freshly mown grass; another documented scores of functional olfactory receptors, in multiple bird species. Olfaction in birds is more widespread than most people have realized.