At the beginning of the dry season, huge flocks of red-billed quelea arrive at the waterhole in Kenya's Tsavo National Park.
Each of these small birds takes only a few beaks full of water and yet such a flock drinks thousands of litres a day. The waterhole is shrinking faster and faster and for the animals and plants it is a matter of sheer survival. Only once the rain finally returns does the eternal cycle of growth and decay come full circle.