Toxic Toads Could Potentially Wipe Out Madagascar’s Biodiversity


When toxic toads invaded Madagascar’s largest seaport, biologists quickly responded with a gloom warning that the invader could devastate the African island’s unique biodiversity, including animals found nowhere else on Earth such as lemurs and hundreds of other species.

This toxic invasive species – the Asian common toad – thwarts off its predators by secreting a deadly poison known to trigger cardiac arrest. However, certain snakes, rodents, and even hedgehogs can eat the toads without any issues due to genetic mutations that make them impermeable to the toxin.

The big question was, whether or not Madagascar’s predators, which evolved on the secluded island, managed to develop similar mutations.

“Madagascar has been isolated for 80 or 90 million years, and has never had toads,” says Wolfgang Wüster, a herpetologist at Bangor University in the United Kingdom. 

So Wüster wanted to find out which species on the island carried the protective mutations.

What he and his colleagues discovered, was only one species – a rodent called the white-tailed antsangy – capable of eating the toads, Science Mag reports

All other predators on the island – lemurs, snakes, lizards, and other native species – are left vulnerable to the toad’s toxin should they start feeding on  the little critters. “Small amphibians are very, very easy prey,” Wüster says. “There’s not many things that wouldn’t eat them.”

Luckily, the toads have only been spotted in one area of the island along the northeastern coast, so we can breathe a sigh of relief, for now anyway. But their range is rapidly expanding,” stated James Reardon, a conservation biologist with New Zealand’s Department of Conservation in Te Anau. 

“This is one of the most invasive species in the world,” says Fred Kraus, a herpetologist at the University of Michigan in Ann Arbor. “So I don’t see anything stopping it. . . at this point, you’d need millions and millions of dollars.”

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