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 Mustelids have never colonised Stewart Island/Rakiura, but feral cats were present. During a survey, it was apparent that cats killed kakapo at a rate of 56% per year. At this rate, the birds could not survive on the island and therefore an intensive cat control was introduced in 1982, after which no cat-killed kakapo were found. However, to ensure the survival of the remaining birds, scientists decided later that this population should be transferred to predator-free islands; this operation was carried out between 1982 and 1997. In 1989, a Kakapo Recovery plan was developed, and a Kakapo Recovery programme was