The Serengeti is a vast ecosystem, home to a dazzling variety of life, and the site of the largest migration on the planet. Woodland, riverbank forests and swamps provide cover for dozens of mammal species and more than 350 varieties of bird. The fate of these animals is intimately bound with the ever changing landscape. The passage from the rainy season to the dry season means there is no rest and no stability. Those who dwell here must remain in constant motion to survive. For months they live in hope of the returning rains that will put an end to their struggle and reward their efforts.