Crocodilians are the closest surviving relatives of the great dinosaurs. They have changed very little during the 150 million years that they have lived on Earth.

The Nile Crocodile

The Nile Crocodile is one of the largest of all crocodilians (the estuarine crocodile, the most aquatic and marine of all crocodilians, living in South India, Indonesia and South Australia, is reputed to be the biggest of all). It preys on almost anything, including hoofed animals that drink at the water's edge, predatory fish - and sometimes humans! The crocodile uses its strong jaws and teeth to drag an animal underwater and drown it. It cannot chew, so it clamps its jaws and spins its own body to tear off large chunks of flesh. It eats every part of the body, including bones and antlers, which help digestion.

Breeding: Nile crocodiles begin to breed when they are around 2.5m in length - this may take 7 years to achieve. Mating occurs in the dry season and, when the rainy season begins, the female digs out a nest in a bank near the water. She lays up to 80 white hard-shelled eggs, covers them well with sand and guards them for about 3 months. When the young are ready to hatch, they begin to call with squeaky 'chirps' and their mother digs them out of the nest. As the miniature crocodiles (about 30cm long) hatch, the female gently picks up a few at a time in her jaws and carries them to a safe nursery area in the water. She will guard them from predators for several more weeks until they go off on their own. At first, the young feed on insects and then, as they grow (about 25cm a year), progress to crabs, birds and fish before tackling the adult diet.

Despite the mother's protection, very few crocodiles reach adulthood. Large lizards, mongooses, hyenas, birds, large fish and other crocodiles all eat hatchlings.

Read More: The Nile Crocodile and Humans

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