They go back a very long way, these scaly, semiaquatic predators. Distant cousins of the dinosaurs, they are said to have hardly changed at all in over two hundred million years.
Absorbing documentary The Dark Side Of Crocs (January 10th, 7.20pm) follows a pair of Nile crocodiles in their African river habitat. These are treacherous waters, shared with neighbours such as the formidable – and equally aggressive – hippopotamus. Remarkably, the two species have managed to coexist, albeit uneasily. Despite their vicious reputation, Nile crocodiles can be surprisingly social, living in groups.
In the wilds of Africa, water comes and goes. While it is essential for survival, few creatures can call the river home. Learn all about these tough, thick-skinned river reptiles and their age-old way of life.