River of fear - Australia's salt-water crocodiles:

Salt-water crocodiles, known in Australia as "salties", grow to up to 7 m in length and are the world's largest land-based reptiles. These salt-water crocodiles can live to be 70 years old. Males which are nearly mature are driven away by the older ones. Then they go on their travels and look for their own territory. In doing so, they are often seen in the sea (which is where they get their name). They can swim for several hundred kilometres in the open sea and are found up to 100 kilometres inland. At the Crocodylus Park in Darwin we find out from crocodile researchers Grahame Webb and Charlie Manolis what exactly it is that makes salt-water crocodiles so dangerous: they have a whole series of highly specialised senses all fine-tuned for one purpose only – catching prey.

Salties will attack anything that is either in front of or beside them, because it could be potential prey. Close-up we witness the tremendous strength of their jaws and the way salt-water crocodiles take their prey for a "roll" which is their way of tearing off large chunks of meat or whole members from their prey. And the sexes are aggressive towards each other except during the mating and egg-laying period, when they demonstrate tenderness. The babies are carefully watched and, after they have hatched, are carried to the water in their mother's mouth. The Aborigines consider the salt-water crocodiles to be sacred and believe that they incorporate the souls of those that have died…