Wednesday, June 30, 2010

Pitohui

I feel like I've been writing a lot about poison and neurotoxins lately, but hey, interesting! Pitohuis (pronounced pit-oo-eey) are the six species found within the genus Pitohui. (clever) They are all brightly colored songbirds endemic to New Guinea. They are also among the most toxic birds in the world. One species, the Hooded Pitohui (Pitohui dichrous) takes the top prize as the most poisonous bird on earth! (It is also interestingly the first poisonous bird ever discovered)

Hooded Pitohui from Smithsonian
Pitohuis do not actually produce their own poison. They consume beetles of the Choresine genus, who themselves produce high amounts of batrachotoxins (BTX), a type of neurotoxin. This is the same substance that makes Poison Dart Frogs so dangerous, and the word batrachotoxin itself comes from the Greek for "Frog" and "Poison." Anyway, after beetle consumption the toxin then finds its way into the skin and feathers of the Pitohuis, and serves to detract predators. The toxin is pretty dangerous, it "depolarizes nerve and muscle membranes by binding and activating voltage-dependent sodium channels." (SOURCE)

The man who first discovered the toxicity of these birds actually did so because he got scratched and bit by a specimen, and then put his finger in his mouth.... and then his tongue and lips went numb. Just touching the feathers of a Hooded Pitohui can cause eye irritation and sneezing. A rather interesting study was done on Pitohuis and Chewing Lice (the source I linked to above) that shows lice prefer to live in feathers that do not contain the toxin. So not only does it protect from larger predators that may want to eat the bird, but it protects them for parasites as well.

But now enough about the poison and on to some other information. As previously mentioned, Pitohuis consume beetle, though they also consume other insects, and will also eat fruits and seeds. All six species are brightly colored, typically with various shades of orange, red, and black. They lay 1-2 eggs at a time, and grow up to about 24cm in length.

Thanks again to Jon for the suggestion!

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