It's dawn on Darwin Harbour and government ranger Kelly Ewin - whose job is to catch and remove crocodiles - is balancing precariously on a floating trap. Heavy rain clouds from the storm that has recently passed are overhead. The engine of the boat has been cut so now it's mostly silent – that is, apart from the intermittent splashing coming from inside the trap. "You get pretty much zero chances with these guys," says Ewin as he attempts to loop a noose around the jaw of the agitated reptile. We're in Australia's Northern Territory (NT), home to an estimated...