For example , local populations of Varanus panoptes dropped by up to 90 % when their habitat was invaded by cane toads .
There are a number of reports of declines in goanna and snake populations after the arrival of toads .
Local populations of Varanus panoptes dropped by up to 90 % when their habitat was invaded by cane toads .
There are a number of reports of declines in goanna and snake populations after the arrival of toads .