Above and beyond: Overachievers in the bird world

Birds are capable of feats of endurance that beggar the human imagination. They survive and reproduce almost everywhere on earth, from the hottest, most inhospitable deserts to the icy expanses of the Arctic and Antarctic. Some dive hundreds of metres below the ocean’s surface, while others migrate over the planet’s highest mountains. This article explores the adaptations of those species that push the avian limits of long-distance flight and altitude, heat or cold tolerance, and unpacks some of the physiology that makes these achievements possible.