Wildlife

Toxic Toad Could End Up Killing the Predators on Madagascar

An invasive species of toad in Madagascar is even more dangerous to local wildlife than previously suspected — its poisonous slime is deadly to just about any local predator, including endangered lemurs, that tries to eat the amphibian.

The Asian common toad (Duttaphrynus melanostictus) is a newcomer to the island of Madagascar, and in just a few years it has spread rapidly. Invasive species upset the balance of local diversity and can cause big problems for native animals, but scientists recently learned that the runaway success of the toad could have even more troubling consequences than thought.

In the evolutionary arms race of predator versus prey, animals that habitually eat toxic creatures often evolve resistance to their poison, in the form of genetic mutations.

But when invasive species suddenly arrive in an ecosystem — as the Asian common toad did — would-be predators that have never encountered the toxic invader before are exceptionally vulnerable to the unknown threat lurking in the body of their next meal.

77 Malagasy species that would be likely to eat the poisonous pests, including 28 birds, 27 snakes, 12 frogs, eight mammals and two lizards. And except for one type of rodent, every species lacked the genetic mutations associated with resistance to the toad's poison.