Science //

Saltwater crocodiles develop a taste for sharks

Felicity Nelson pits man-eater against man-eater.

Photo by Fayes4Art via Flickr

Australia is home to some of the most deadly creatures in the world. We boast a healthy population of baby-eating dingoes, one of the world’s most toxic spiders, a scary number of tiny but lethal box jellyfish, and (if that hasn’t made you cancel your trip) even our furry national icon, the platypus, produces a painful toxin. Amongst this nightmarish collection of dangerous animals there are two particularly nasty creatures that regularly have humans on their lunch menu: sharks and saltwater crocodiles.

Saltwater crocs are normally around 4m long, but they can grow up to 7m. An adult salty can launch its entire body vertically out of the water to catch prey and can deliver more bite force than a T-rex with a snap of its jaws. Crocs are quick learners and can track the habits of their prey, waiting for precisely the right time to strike.

Saltwater crocs kill an average of two people every year in Australia. Nowhere is the threat more pronounced than in the NT where over 150,000 individual saltwater crocodiles patrol the coastal river systems. Crocs are becoming such a public safety concern that the NT Government is planning to ease the ban on trophy hunting of adult crocodiles to assist population control.

In a nation of beach-junkies man-eating sharks pose an obvious problem. There are three culpable species: the bull shark, the tiger shark, and the great white. This means man-eaters can range from 2-6m long and have up to 50 teeth at the front of their mouth and 5-6 rows behind (too many teeth for comfort.)

Large saltwater crocodiles aren’t fussy eaters and will make a meal of practically anything they can get their teeth into – goannas, kangaroos, toads, and even Bengali tigers (on occasion). As it turns out, they also have quite an appetite for sharks. Recently a number of saltwater crocs have been observed hunting bull sharks in Darwin Bay and Kakadu National Park. Five fishermen found themselves having to fend off a croc to protect their prize shark catch at one point. It seems the Northern Territory will soon have one less hazard to worry about if the croc population keeps growing.

Sharks and saltwater crocodiles are the kings of Australian waters and two of the many awesome terrors found in the country. It seems ironic to be passionate about something that wants to eat you, but these powerful creatures really deserve to be admired.

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