Cane toads have begun their ‘death-march’ across the Kimberley over the past four or five years. Some predators, like freshwater crocodiles and monitor lizards are being almost wiped out, and others like quolls are being trained to avoid the toads and their spawn.
One benefit surprisingly is the effect on birds:
A pity that feral cats learn too quickly that the toads are poisonous.
[…] An honours student did an intensive investigation of the finches, which nest in the low-growing pandanus (Pandanaceae) tree.
They checked one hundred nests every two days, following the birds through to fledgling stage and using cameras on nests to demonstrate the predation rates.
The two studies showed the finch population increased because the two goanna species preying on eggs and fledglings, the monitor lizards V. mitchelli and V. mertensi, had declined by nearly 50 per cent.
“You get these predators dropping out essentially and their prey numbers go up and the prey numbers of those animals goes down and we get all these shifts,” Prof Doody says.
“In some systems it can be like that puzzle game where you pull one piece out and you hope the whole thing doesn’t fall apart.