National Geographic : 1978 Jan
Full-grown crocodilians range in size from three feet to more than 25, from a few pounds to more than a ton. We can only guess how long they live-some for perhaps a hundred years or more. A few species prefer solitary lives, but most, we now know, have sophisticated social or ders. Their grunts, hisses, chirps, and growls each carry specific messages. They also use a "body language" of back arching, bubble blowing, and other physical displays. Crocs may communicate underwater, too, through low-frequency warblings inaudible to us. A big Nile croc is cunning enough to stalk a human, strong enough to bring down and dismember a water buffalo, yet gentle enough to crack open its own eggs to release its young. Down-under Crocs in Trouble It was the first of many crocodile days. I had flown into the Aboriginal settlement at Maningrida in northern Australia, two hun dred miles east of Darwin, to attend a croco dile conference of the International Union for Conservation of Nature. Eleven croc special ists-a hefty percentage of the world's total had convened at a research station set up by the University of Sydney and the Northern Territory. The Maningrida team studies, and hopes to salvage, what's left of Australia's saltwater crocodiles. The saltwater croc is the biggest and some say the most dangerous of crocodiles. Fisher men in Queensland once hauled in one that reportedly measured 33 feet. Historically they have ranged from India to Australia. They have been found at sea beyond Fiji, although, like most crocodiles, they dislike waves and prefer calm estuaries. I went up one of those estuaries with grad uate student Bill Magnusson. Bill needed to change film in a time-lapse camera he had set up over a crocodile nest he was studying. Bill's legs were scarred with the tropical ulcers one picks up (Continued on page 96) Fourteen feet of terror, a Nile crocodile prowls South Africa's St. Lucia estuary re search station. Although the species, which ranges over much of Africa, commonly preys on antelopes, Cape buffalo, and even man, crocs as a group subsist mainly on smaller fare, such as frogs, turtles, crabs, and fish.