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 metabolic demands in comparison to flighted birds. It is able to survive easily on very little or on very low quality food sources. Unlike most other bird species, the kakapo is entirely herbivorous, feeding on fruits, seeds, leaves, stems, and rhizomes. When foraging, kakapo tend to leave crescent-shaped wads of fiber in the vegetation behind them, called "browse signs". Having lost the ability to fly, it has developed strong legs. Locomotion is often by way of a rapid "jog-like" gait by which it can move several kilometres. A female has been observed making two return trips each night during nesting