What animal, introduced to Australia in the 19th century, had a feral population there by 2010 of between 500,000 and 750,000?
Camel No, not rabbits: the feral rabbit population was estimated at 200-300 million in 1991. Nor cane toads: introduced in 1935 by the Bureau of Sugar Experiment Stations to control the native cane beetle, there are now 200 million of them.
