Poisonous Birds Are What They Eat

Ask, Apr 2005 by McKenzie, Aline

Scientist Jack Dumbacher was in New Guinea (a large island north of Australia) catching birds to study, when a pitohui bird bit and 4 scratched his hand. The cuts stung, and when he tried sucking on an injured finger, his tongue and lips immediately became numb. What gave the bird's bite its sting? The pitohui's skin and feathers contain a rare poison-the same poison found in Colombian poison dart frogs, half a world away.

These birds and frogs both store poison in their bodies to protect themselves from parasites and predators. But where does the poison come from? The birds and frogs aren't born with it, and poison dart frogs raised in a lab or at a zoo aren't poisonous at all. Scientists thought the animals probably got the poison from a bug or plant they ate in the wild, but no one knew what this toxic snack was until villagers in New Guinea told Dumbacher about a tiny beetle that makes your mouth go numb and tingly. Sure enough, samples of the beetle showed it contained the rare poison, and similar beetles are found in South America, the home of the poison dart frogs.

Now scientists have just one more mystery to solve: how the birds and frogs eat poisonous beetles without being poisoned themselves.

-Aline McKenzie