Deep in the New Zealand forest, the booming thud of the kākāpō’s ancient mating ritual sounds more like a bass speaker than birdsong. What’s more, it risks falling silent forever. This sound comes from no ordinary green bird. The astonishingly rare kākāpō is the world’s heftiest parrot, weighing up to 8 pounds and living for as long as 90 years despite being flightless and almost blind. Source link