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 of the birds had died and the fifth died after about four years. In the next 12 years, regular expeditions found few signs of the kakapo, indicating that numbers were continuing to decline. Only one bird was captured in 1967; it died the following year. By the early 1970s, it was uncertain whether the kakapo was still an extant species. At the end of 1974, scientists located several more male kakapo and made the first scientific observations of kakapo booming. These observations led Don Merton to speculate for the first time that the kakapo had a lek breeding system. From