I find it hard to get excited about the fine details of a bird’s plumage, which are the subject of such fascination, discussion and even controversy among birdwatchers. It surprises me that the essential feature of birds, which defines their ‘birdness’, is so neglected. This is their power of flight. The evolution of flight has reshaped thier bodies and has had a massive impact on every aspect of their natural history, but their use of flight recieves little attention in books on birds.