Nile crocodile

A mother Nile crocodile gently carries her tiny hatchlings to the water in her huge mouth. She guards her sandy nest for about three months, then digs out the chirping babies. Surprisingly, crocodiles' closest living relatives are birds, not lizards. Crocodiles are also cousins of the giant dinosaurs that lived long ago.

It is Africa's largest crocodile. Large males grow to about 5 metres long, as long as a large car, and weigh hundreds of kilograms, as much as several grown-ups together, while females are smaller. Very large males can be even longer and much heavier. It has a long low body coloured dark bronze to olive with black spots, a pale belly, and a strong tail flattened from side to side for swimming. Bony plates armour its neck and back.

It lives in rivers, lakes and marshes across much of Africa south of the Sahara, up the Nile to southern Egypt, and in Madagascar. It basks on sandy banks by day and spends nights in the water. Adults eat mostly fish but also take large animals such as antelope and zebra, holding food with sharp teeth instead of chewing.