Poison-dart frogsmay now have to share the distinction of being the cutest toxic critters. According to a report published today in the Proceedings of the National Academy of Sciences, researchers have determined that a brightly colored New Guinean bird known as the blue-capped ifrita possesses the same toxins found in the attractive amphibians, making it the second bird genus known to possess such poisons. The study also identifies several new toxins in the feathers and skin of species from both avian groups.

Previous findings from the same investigators had revealed that three bird species in the genus Pitohui (right) bore the defensive toxin known as homobatrachotoxin. The new study adds two more Pitohui species to the list, as well as Ifrita kowaldi, and similarly expands the batrachotoxin repertoire. Both bird groups are found only in New Guinea and have long been recognized by villagers as being toxic. Indeed, the scientists report, among Madang Province villagers, the Ifrita is called "Slek-Yakt," or "bitter bird," and is known to cause irritation if eaten or handled. The researchers themselves got a taste of the negative effects of two particularly potent Pitohui species, experiencing sneezing and upper respiratory irritation while handling the birds during fieldwork.

Because toxin levels vary widely among individuals and species, the birds, like poison-dart frogs, probably obtain these toxins from their diet, rather than manufacturing them themselves. But the exact source remains unknown, because the batrachotoxin substances have not yet been detected in the birds' stomach contents or in the insects they feed on. Whatever their origin, they appear to be effective deterrents, repelling New Guinean hunters and probably other predators as well.