Saltwater Crocodile (Wikipedia)

Australian salties or saltwater crocodiles, hunted to near extinction in the 19th Century, have made a comeback in the Darwin area of northern Australia and now number 100,000 or so, close to the total living naturally there before.

These superb predators, Crocodylus porosus, have evolved for over 50 million years to be today among the wild's most efficient killing machines. And their menace is not restricted to nonhuman prey. Around Darwin, roughly one person a year gets "taken." In 2010, an eleven-year-old girl was swimming when she became the latest such victim. Protected by federal law, the now more numerous salties have begun to expand into areas considered safe for people, like fresh water rivers, backyards, lagoons, even swimming pools. Real life Crocodile Dundees, rangers whose capture and removal jobs can entail wrestling with crocs and taping or tying the jaws of behemoths that have gotten into human habitation areas, take them to safer places or to croc farms.

Darwin residents, despite the risks, mostly see the crocs as a net positive. They certainly are good for tourism. And Australian crocodile farms legally harvest, sell, and ship about 50,000 croc hides a year, for use in fancy footwear, purses, wallets, tote bags, and such.

Over the long struggle between reptiles and mammals, the latter sort of creature currently has the upper hand. Yet the hazards of living among saltwater crocs in and around Darwin dramatically shows what a close thing it may have been at times. Even now, the crocs' diets include plenty of kangaroos, monkeys, dingoes, bats, wild boar, water buffalo, pets, and domestic livestock. In another ten thousand years, who can say how the ebb and flow of this competition may have turned out?

Primary sources:

Australian Saltwater Crocodiles. Birgit Bradke in Outback Australia Travel Guide, last updated in 1999.

Saved From Extinction, Darwin's Crocs Are Now King. John Burnett on NPR, February 10, 2012.