Coping with the weather
Special adaptations help birds to survive the very worst of our weather.
How birds have adapted
Birds, like mammals, are ‘warm-blooded’. This means they generate their own body heat, instead of depending on the weather to warm them up, unlike reptiles. This means birds, like mammals, can survive in the coldest places on Earth. Emperor penguins can sit out the Antarctic winter at temperatures of -50ºC. Bar-headed geese can survive the same temperatures while flying at jet-plane height right over the top of the Himalayan mountains.
Special adaptations keep birds’ body heat inside. Feathers can fluff out to trap warm air, and are a useful place to tuck away your head when it gets cold. Fat that builds up under a bird’s skin as cold weather approaches also helps to keep it warm – just like thermal underwear.
Legs and feet
You might think that a bird’s bare legs and feet get very cold but a cunning adaptation of their circulation system prevents this. The arteries that carry warm blood from their heart pass right alongside the veins carrying cold blood from the legs, heating them up. In hot weather the flow of warm blood to the legs increases, so the bird can lose unwanted heat and keep cool.
Moving to survive
Pink-footed geese migrate from Iceland and Greenland to spend the winter in Britain. Flying gives birds a head start when it comes to dealing with tough weather and harsh climates.
Food is found in different places as the weather changes. Many birds have adapted their feeding behaviour to take advantage of this. During autumn, when there is a rich crop of berries, thrushes such as fieldfares and redwings feed in hedges. In winter, when the berries run out, they fly to fields and lawns to feed on worms. Their beaks are adapted for both jobs.
Sandgrouse are ground-nesting birds from the deserts of Africa and Asia. They nest in baking temperatures, far from water but adults have an amazing way of getting water to their young. They fly more than 50 kilometres to the nearest waterhole, where they use special feathers on their belly to soak up water like a sponge. They then return to the nest, where the young spoon the water out using their beaks.
The best way to escape bad weather is to fly away somewhere nicer. This is called migration, and many millions of birds do it every year. Migration means that they find the best place to breed during summer and the best place to feed during winter.