Birds and Their Extraordinary Sense of Smell

Smell is one of the five senses we use to experience the world. It allows humans and other animals to find their food, avoid danger, and even recognize family members. Animals detect smells with olfactory receptors, special proteins that sit on the surface of the nose cells. These interact with odor molecules (small particles that have a smell) and send signals to the brain so the animal can perceive the smell. We know mammals have hundreds of olfactory receptors and can detect tens of thousands of smells, but what about birds? For decades, many people thought that birds did not use smell in their daily lives, but recent studies have shown that birds respond to smell. We show that many birds have a large number of olfactory receptors similar to mammals, strengthening the case for smell playing an important role in the life of birds.