A changing climate and animals on the move

Migration is a behavioural adaptation: animals travel from one place to another, usually with the seasons, and then return. The steppe eagle breeds in the north in summer. In autumn it flies south to warmer lands, and in spring it flies north again. Egypt lies on the way, so every year millions of birds pass over the Red Sea coast and the Nile valley, looking for food, water and places to rest. Large birds save energy by gliding on rising warm air instead of flapping all the time, and their broad wings, a structural adaptation, help them. The journey is hard. There can be bad weather, enemies, too little food and water, and fewer safe resting places because people have changed the land. Birds that are strong and healthy are more likely to complete the trip. Migration is a behaviour, not a body part.