The Kakapo is the world's only flightless parrot and one of the world's longest living birds (120 years). Kakapo are nocturnal and herbivorous. Having evolved on an oceanic island with few predators and abundant food, they became the world's heaviest parrot and lost the ability to fly. Polynesian and European colonisation, with accompanying mammalian predators, have meant that the Kakapo is now critically endangered with only about 130 alive.
The Kakapo has a variety of calls, including a long low frequency "booming" by males to attract females. The Kakapo has one of the lowest rates of reproduction among birds, with breeding only happening in years when trees fruit heavily, providing a plentiful food supply to these expert climbers.