Pitohui: The First and Only Toxic Bird on Earth

The Pitohui, a small bird endemic to Papua New Guinea, holds the distinction of being the first and only toxic bird scientifically confirmed in the world.

Indigenous people in Papua New Guinea have long known to stay away from the Pitohui bird due to its toxic nature. However, for the Western world, the discovery of its poisonous properties was only made by chance just over three decades ago.

In 1990, ornithologist Jack Dumbacher was on the Pacific island in search of paradise birds when he set up mist nets between trees to capture them. To his surprise, he caught some Pitohui birds. While attempting to release them from the nets, the birds scratched and bit his fingers, prompting him to instinctively put his hand in his mouth to ease the pain. Almost immediately, Dumbacher felt his lips and tongue go numb. Suspecting that the strange symptoms were caused by the birds, he put a Pitohui feather in his mouth and experienced the same tingling sensation.

These birds are found in Papua New Guinea, belonging to the Pachycephalidae family. They have colorful plumage and are omnivorous. Locally, they are referred to as “rubbish” birds due to their distinct foul smell. Consuming the meat of this bird can be unpleasantly bitter and may cause illness.

In the same year of Jack Dumbacher’s accidental discovery, other scientists were also preparing to study this unique toxic bird after experiencing tingling and burning sensations when touching its feathers. However, most sources credit Dumbacher with being the first to uncover the toxic nature of the species. He asked the local people in Papua New Guinea about the Pitohui bird, and they seemed to be well aware of its toxicity. They referred to it as the “rubbish bird” because of its foul smell when cooked, and the indigenous people only consume it when they have no other food sources.

To learn more about the Pitohui birds and their toxins, Jack Dumbacher sent some feathers of the species to John W. Daly at the National Institutes of Health, a leading scientist in natural toxins. In the 1960s, Daly had identified batrachotoxin as the poison in the toxic dart frog species in Colombia, and later, he found the same family of toxins in the feathers of Pitohui birds.

This was the first time scientists had discovered that this bird species harbored the toxic batrachotoxin (which causes paralysis, internal bleeding, organ destruction, and gradual death in victims). Currently, there are six species of Pitohui birds, with the most dangerous being the Hooded Pitohui.

The compounds called batrachotoxins (BTXs) are neurotoxic alkaloid steroids that disrupt the flow of sodium ions through channels in nerve and muscle membranes, causing tingling and burning at low concentrations and paralysis, cessation of heart, and death at higher concentrations. They are recognized as the most toxic compounds by weight in nature (over 250 times more toxic than strychnine).

Pitohui – Wikipedia tiếng Việt

Research later revealed that the Pitohui birds store the toxin both in their skin and feathers, as well as in their bones and internal organs, though at much lower concentrations than in toxic frogs. Interestingly, the batrachotoxin concentrations vary significantly between individuals and geographic regions.

The origin of the toxin within the bird’s body has been a subject of much debate among scientists, but the general consensus is that the birds do not produce the toxin themselves but acquire it from their diet, especially from a type of beetle called Choresine, which also contains this poison.

The reason why Pitohui possesses this toxicity is still not fully understood. Some scientists believe it may be a form of defense against predators or a result of consuming toxic prey. However, ongoing research continues to shed light on this intriguing phenomenon and its implications.