Kakapo than females. Twenty-eight males were found to average in one study, and 39 males were found to average in another. In the same studies, 28 females were found to average and 18 females were found to average , respectively. Kakapo are the heaviest living species of parrot and on average weigh about more than the largest flying parrot, the hyacinth macaw. The kakapo cannot fly, having relatively short wings for its size and lacking the keel on the sternum (breastbone), where the flight muscles of other birds attach. It uses its wings for balance and to break its fall when
Kakapo areas of Fiordland. Kakapo seem to have preferred broadleaf or mountain beech and Hall's tōtara forest with mild winters and high rainfall, but the species was not exclusively forest-dwelling. All kakapo that were transferred to predator-free islands in the last decades have adapted well to any changes in environment and food plants. It seems that the kakapo – like many of New Zealand's bird species – has evolved to occupy an ecological niche normally filled by various species of mammal (the only non-marine mammals native to New Zealand are ). The kakapo is primarily nocturnal; it roosts under cover in