Toxic toads that arrived in Madagascar as an invasive species pose a threat to the island nation’s wildlife because – unlike animals in the toad’s native Asia – they’ve developed no gene mutations to protect them.
That’s the conclusion of a team of European researchers who urge the government in Antananarivo to make it a conservation priority to control the Duttaphrynus melanostictus, or Asian common toad. Its presence has already spread rapidly across the island nation known for its biodiversity, and it’s likely too late to eradicate it completely.
“The fear is that the toads will send shockwaves through the entire ecosystem: the presence and spread of the Asian toads could threaten many endemic predators as they are poisoned by eating the toads, and in turn their prey, such as rodents, could increase in numbers,” said Dr. Wolfgang Wüster, a herpetologist at Bangor University’s School of Biological Sciences in the UK.
Wüster, the senior author of the paper, helped to lead a team of scientists from Bangor, Liverpool School of Tropical Medicine, the University of Braunschweig and the Natural History Museums of Munich, Stuttgart and Turin. Their research paper is published in Current Biology this week.
Madagascar has no native toads, and conservationists have assumed that native vertebrates would lack mutations that confer resistance to the toad toxins, while debating the scope of impacts and appropriate responses.
“Our findings mean that conservation priorities and resources can now be allocated based on robust data rather than supposition,” Wüster said.
Image: Dr. Wolfgang Wüster