Photo: Jan Messersmith
In the early 1990′s, ornithologists were stunned to learn about the discovery of poisonous birds. Several species of the genuses Pitohui and Ifrita of New Guinea were discovered to have toxins in their skin and feathers. Surprising still was the identity of the toxin. It’s a batrachotoxin, a poison also found in the skin of South American poison dart frogs. It’s one of the most deadly natural toxins in the world.
In the case of the frogs, it appears that they acquire the toxin from something they eat. If raised in captivity, they do not have the poison. However, scientists have so far been unable to find the toxin in a plant or insect in the frogs’ natural habitat.
Scientists suspected the birds acquired the poison from a food source as well, but what? The birds eat a wide variety of insects, maybe as many as thousands of different species.
Then scientists came upon a beetle of the genus Choresine. Villagers of Herowana, Papua New Guinea, called this beetle by the same name as one of the poisonous birds, nanisani. Nanisani refers to the tingling and numbing sensations one gets from contact with the birds or the beetles. Sure enough, the beetles contain a batrachotoxin too. And inspection of one of the bird’s stomachs revealed one of the beetles.
Beetles of the same family as Choresine are found around the world, including South America, the home of the poison dart frogs. That the birds or the frogs acquire the poison from the beetles isn’t clear though. It could be that the birds, frogs, and beetles all acquire the poison from some other yet-to-be-discovered source.