Kakapo became isolated from the remaining parrot species when New Zealand broke off from Gondwana, around 82 million years ago. Around 30 million years ago, the kakapo diverged from the genus "Nestor". Earlier ornithologists felt that the kakapo might be related to the ground parrots and night parrot of Australia due to their similar coloration, but this is contradicted by recent studies; rather, the cryptic colour seems to be adaptation to terrestrial habits that evolved twice convergently. The kakapo is a large, rotund parrot; the adult can measure from in length, and weight can vary from at maturity. Males are larger
Kakapo approximately every five years, with the ripening of the rimu fruit. In mating years, males making "booming" calls for 6–8 hours every night for more than four months. Each court consists of one or more saucer-shaped depressions or "bowls" dug in the ground by the male, up to deep and long enough to fit the half-metre length of the bird. The kakapo is one of only a handful of birds in the world which actually constructs its leks. Bowls are often created next to rock faces, banks, or tree trunks to help reflect sound: the bowls themselves function as amplifiers