Eighteen birds left on Earth, and New Zealand thought they understood them—then something impossible followed. These rarest of flightless creatures had survived isolation for centuries, yet researchers tracking their final wild population noticed behavior no science could explain.
In 1974, ornithologist Don Merton received approval for one final expedition into the mountains of Fiordland, New Zealand. His official task was to confirm that the kakapo, a large flightless parrot, had gone extinct. In the previous 25 years, the Wildlife Service had run 61 expeditions into the region and found only six birds, five of which had died.Instead of evidence of extinction, Merton found…