Saltwater crocodile named world’s most aggressive

Australia’s saltwater crocodile has beaten contenders from the US and South America to be named the world’s most aggressive crocodile, as new guidelines are released on how to avoid altercations with the formidable predators.

A study conducted by Charles Darwin University in the Northern Territory found that the Crocodylus porosus, colloquially known in Australia as the saltie, was much more aggressive than six other species of crocodiles selected from around the world.

The research, conducted in Darwin and India, monitored juvenile crocodiles with infrared cameras over two years. The crocodiles were grouped as young hatchlings and animals about a year old.

Researchers found that the saltwater crocodile exhibited vastly more bellicose behaviour than species from Papua New Guinea, South America and south-east Asia. The freshwater crocodile, also found in Australia, was ranked fifth, ahead of the American alligator and the Indian gharial.

The saltwater crocodile underlined its fearsome reputation by being the only species to exhibit agitated tail twitching followed by lunging head strikes on its opponents.

“They are certainly the ugliest when it comes to aggression,” said Matthew Brien, wildlife biologist at Charles Darwin University. “They get in an agitated state then wind themselves up and swing their heads into other crocodiles. When you see larger salties, especially males during mating season, it’s quite fearsome. It’s like a sledgehammer that would certainly shatter your head.”

By comparison, other species of crocodile are social and even gentle with each other. The Indian gharial is, according to Brien, “a real sweetheart”, with a delicate, narrow snout and pleasant disposition.

Brien said aggression in saltwater crocodiles is “hardwired from hatching” but there is no clear explanation why the species is so short-tempered. One theory is that competition with other crocodiles, combined with its sheer size, has instilled the aggression.

The saltie’s No 1 ranking arrived as the Queensland government issued new guidelines on how to avoid being attacked by the animals.

Crocodile handlers have started patrolling the northern beaches of Cairns and have already removed two of the animals. Under the crocodile management plan crocs will be removed from areas popular with locals and tourists and taken to farms or zoos.

The state environment minister, Andrew Powell, said: “While we will do everything we can to put the safety of people first, we must accept that we can never make Cairns entirely croc-free.

“As we move into what we hope will be another busy holiday season it is vital that everyone, including locals and tourists who may be visiting the area on holidays, practise crocwise behaviour.”

The “crocwise” guidelines include a warning not to swim in waters where crocodiles may live and to obey warning signs, a reminder that crocodiles also swim in the ocean and advice not to leave food or bait near water, campsites or boat ramps.

People are urged to stand back from the water when fishing and to ensure they do not “provoke, harass or feed” crocodiles.

Brien said saltwater crocodiles displayed different behaviour when catching prey compared with when they fought each other, but that the vast size of the animals posed significant dangers to people.

“A two-metre croc won’t eat a human, but once you get an animal that is four metres long, humans are certainly on the menu,” he said. “You really do have to take precautions in croc habitat.”