When crocodiles attack: Why people become prey

Crocodile attacks have become more common in the past couple of decades as the protected species has recovered in numbers, and human populations have grown and encroached on the reptiles’ territory.

The death of a Newcastle doctor and father-of-three on holiday this week in Queensland was the third fatal crocodile attack in Australia this year, following one in Queensland in April and another in the Northern Territory in July.

How common are crocodile attacks in Australia?

Saltwater crocodiles are apex predators that can live up to 70 years and grow up to six metres long and weigh up to 1000 kilograms. A crocodile over 4 metres is considered large.

A crocodile on the banks of the Daintree River.Credit: Paul Rovere

The website CrocAttack keeps track of all known human deaths by crocodile in Australia since 1969.

On average, about one or two people are killed by saltwater crocodiles every year nationally. The attacks usually occur in either Queensland and the NT and occasionally in the northern parts of Western Australia.

Crocodiles have killed 30 people in Australia in the past 25 years, with the annual tally peaking at four in 2014. This compared with 14 people killed by crocodiles from the 1970s to the turn of the 21st century.

Brandon Sideleau, a crocodile researcher at Charles Darwin University who maintains the CrocAttack website, said there were more opportunities for humans and crocodiles to interact, but Australia was doing well.

“We don’t have a crocodile problem at all,” he said.

In Indonesia, for example, there were at least 85 people killed last year by saltwater crocodiles, usually subsistence fishermen taking risks. Some of the deaths in Australia include Indonesian fishermen in our waters.

Why do crocodiles attack humans?

The short answer is because they are hungry and humans are food.

“Crocodiles always have attacked humans and our ancestors, going back hundreds of thousands of years,” Sideleau said. “It is natural behaviour, but it can become excessive if certain individuals learn that humans are easy prey.”

He said crocodiles in Australia typically ate fish, crabs and turtles, and only hunted humans or other large mammals if the opportunity presented itself, if the individual had learned humans were easy food, or there was not enough other prey.

If a crocodile attacked a human, they would usually seize the person and pull them underwater, until they stopped struggling.

In the Cooktown incident, local residents reportedly had been feeding the crocodiles, including with roadkill.

Professor Mike Letnic at the University of NSW said this would have increased the danger.

“The problem with feeding them is that crocodiles are really quite intelligent, and they will begin to hang around in areas where they know there is regular food available,” Letnic said.

Feeding crocodiles was banned, but Sideleau said this was rarely enforced, and penalties were not enough.

Why are crocodiles protected?

Saltwater crocodiles were nearly wiped out by hunting until they were protected in the 1970s, starting with Western Australia in 1970.

The numbers have now rebounded to about 105,000 in the NT, 20,000-30,000 in Queensland and 100,000 in Western Australia.

“They’re in very good shape now,” Letnic said. “We’re becoming increasingly aware that large predators play really important roles in maintaining healthy ecosystems.”

Sideleau said there was a misconception the population would keep growing. As apex predators, the population was self-regulating because if they overpopulated, they starved.

Sideleau said the crocodile population in the NT had been stable for a decade. In Queensland, the species was still considered vulnerable and would probably never recover because of pressure from the large and expanding human population on the coast.

So far, there is no sign that saltwater crocodiles are expanding their range because of climate change. While they have been spotted in Queensland as far south as Maryborough and Fraser Island, both experts agreed this was the creatures reclaiming historical territory.

Both the NT and Queensland governments remove and relocate crocodiles away from towns, and the NT has a permit program permitting third parties to remove crocodiles or eggs from the wild.

Some people advocate for a cull, but Sideleau said this won’t increase public safety, and it would require an eradication program to allow swimming at Kakadu, for example.

What do Australian governments say about crocodiles?

The Queensland government website says “Croc Country”, or typical crocodile habitat, begins at the Boyne River south of Gladstone, and extends northward and around the top to the NT border.

Crocodiles can be found in freshwater and saltwater locations along the coast, from rivers and creeks hundreds of kilometres inland to offshore islands of the Great Barrier Reef.

Crocodiles use ambush tactics, such as lying and waiting at the water’s edge, can stay underwater for over an hour and can be completely concealed, even in knee-deep water. They are most active at night, dusk and dawn.

The government advice is to stay at least 5 metres from the water’s edge, dispose of food and fish scraps in a bin or take them home, keep pets away from the water, avoid using small watercraft such as kayaks and paddleboards, and stay away from crocodile traps.

The NT government website says it should be assumed that any water body in the saltwater crocodile’s natural range was unsafe to swim, unless signposted for swimming.

The Western Australian government website says anywhere in the Kimberley or Pilbara is crocodile country.

What should you do if a crocodile attacks you?

Run for your life. Don’t bother zig-zagging – that is a furphy.

“The idea that crocodiles can chase people on land is just a myth,” Sideleau said.

“They can only do it for short bursts out of the water for maybe 5-7 metres. They can charge out real fast ... but once they’re on land, they’re not very agile.”

Sideleau said most attacks were by crocodiles in the 2.5 to 3-metre range, and an adult human had a good chance of fighting it off. Gouging the eyes was reportedly effective.

However, Sideleau said the fatality rate in deep water was close to 100 per cent.

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