The role of feral cats in decimating the Centre's wildlife has long been well understood: the bodies of dead wildcats, almost panther-like in their size, are often encountered in desert rangelands. But their presence in the far north is more a question of surmise. They are there, doubtless, deep in the stringy-bark forests and ravine systems, under cover, prowling, but only rarely are they seen or caught. When they are removed from the equation, though, mammal numbers recover fast. And if you can't remove the cats, remove the prey.
Five years ago 64 quolls, gravely endangered victims of the cane toad plague, were rounded up from the Top End. They were moved to two cat-free offshore islands; by last year there were more 5000 of them, in greater densities than in their old environment, perhaps a sign that even before the cane toads came, cats had already swept through and begun to kill them off.
Other similar results have done much to highlight the central role played by cats in the collapse of the mammal population.