The great mountain ranges of the world include the Andes in South America, the Rockies in North America, the Alps in Europe and the Himalayas in Asia. The tops of some mountains are so high that they are covered in snow and ice all year round. On the higher slopes there is less oxygen in the air to breathe. Nothing can live there for long. Even on the lower slopes where the snow melts in warmer months, only the toughest plants and animals can survive.

In the Himalayas, food is scarce and the weather harsh. Only animals well protected against the cold winds can live there. Two layers of thick fur keep the enormous yak warm. The snow leopard’s hairy paws protect it from the cold and help it to run across the snow. Small animals, such as the pika, must be on the lookout for fierce leopards if they are to escape into their burrows. The Himalayan ibex moves about the steep slopes on its nimble hooves.