koao

In 1937, renowned explorer Thor Heyerdahl stumbled upon a mysterious bird during a visit to the island of Hiva Oa in the Marquesas archipelago. His encounter with the wingless bird, named "koao" by the locals, left a lasting impression on him, even though the animal quickly disappeared into the thicket. 

It's rare for a celebrity to encounter an extraordinary animal. Such was the case with the late explorer Thor Heyerdahl. In 1937, while on the island of Hiva Oa in the Marquesas archipelago in French Polynesia, he was hiking through the forests and rocky mountains with a local guide when he came across a strange, wingless bird the size of a long-legged gull. The bird immediately fled, diving into a natural tunnel among the dense ferns. Heyerdahl never saw the bird again.

The guide explained to him that it was a bird called "koao" by the natives, so fast that it was impossible to catch it.

There are other reports of the koao. In 1956, French explorer Francis Maziere wrote that it was actually a flightless bird with vestigial wings, the size of a rooster, with purple-blue plumage, and a yellow bill and legs. This description evokes another unusual bird, the New Zealand takahe ( Porphyrio notornis mantefli ). It differs from the koao only in the color of its bill and legs.