Nile crocodiles, one of the most impressive creatures in the world, live in groups in African rivers. Water comes and goes in the wilds of Africa and while all animals need access to water, few can call the river home.

The Wadden Sea is a dynamic environment with huge changing tides - the largest coastal wetland in Europe. The animals and plants that live here - in the water, on the seabed or on land - have adapted remarkable strategies to survive in such a variable environment. The natural world of which they are a part has evolved a finely-tuned balancing act. However, the encroachment of man is putting new pressures on it.