Planet Earth - Season 1 Episode 5

A large and growing part of earth's land mass is covered in desert – each one widely varied in composition and dryness. Wildlife species have adapted in different ways to these different arid lands especially to get and conserve water. Some are physically desert-models, like camels, others just changed their diet and behavior. Most live mainly at night, when it's cooler. The largest desert is northern Africa's Sahara, US size and extremely sandy, the result of grinding erosion of mountains. Short moist moments or periods are taken intense advantage off, leading to such extravaganzas as the locust swarm.