Komerční prezentace
Registrace uživatele

Přihlašte se k odběru informací, novinek, získejte přístup do diskuzního fóra.

Vesmír č. 10
Vesmír č. 10
Toto číslo vychází
2. 10. 2017
Novinky
Zdarma jedno celé číslo Vesmíru v pdf.
• Říjnové číslo Vesmíru
reklama

Jedovatí ptáci

Poisonous birds by Antonín Krása.

Six species of Pitohui birds are examples of strange animal inhabitants of New Guinea. These birds and a distantly related Ifrita kowaldi are poisonous. This feature turned up 20 years ago when an ornithologist, J. Dumbacher, studied these birds and was injured by one of them. But even stranger than the fact of bird toxicity was the discovery of responsible toxins – batrachotoxins. They had been known until then only from South American frog genus Phyllobates. Source of Pitohui toxicity was found in the following years – it comes from small melyrid beetles (Choresine). But a lot of questions are still unanswered, such as whether it is an adaptation against parasites or predators. The recent discovery of parafyletic origin of Pitohui shows that toxicity in birds evolved several times independently, so there can be more poisonous birds around, one of them our Golden Oriole.