So now they have a bounty on Feral Cats and are doing whatever they need to do to eradicate them and the Feral Car population is estimated at 12 million down there.
Wonder what it is here? So trapping them and taking them to spade and neutered is not the answer, it's eradicating them.
It is my understanding that there was no felis catus-domestic cat-in Australia before the early 19th century-they are an introduced species to that place, brought by settlers, along with the disastrously damaging rabbit, before people had enough sense to know not to fool with the natural status quo.
On the North American continent, domestic cats have lots of natural predators-coyotes, wolves, dogs, large snakes, mountain lions, feral hogs/pigs, jaguars, eagles and hawks, etc, etc. Native species of small birds and mammals are not in danger in any way. Australia only has only two of those natural predators-dingos and eagles, so your comparison to what goes on here is apples and oranges.
America is not Australia...
Having a program that “spayed” and neutered feral cats out here has worked fine-in less than 5 years, it has cut the population down to 1/4 of what it was.