Kakapo its specific epithet "habroptilus" comes from "habros" "soft", and "ptilon" "feather". The bird has so many unusual features that it was initially placed in its own tribe, Strigopini. Recent phylogenetic studies have confirmed the unique position of this genus as well as the closeness to the kākā and the kea, both belonging to the New Zealand parrot genus "Nestor". Together, they are now considered a separate superfamily within the parrots, Strigopoidea, the most basal of all living parrots. Within the Strigopoidea, the kakapo is placed in its own family, Strigopidae. The common ancestor of the kakapo and the genus "Nestor"
Bird various adaptations for flight, including a lightweight skeleton, two large flight muscles, the pectoralis (which accounts for 15% of the total mass of the bird) and the supracoracoideus, as well as a modified forelimb (wing) that serves as an aerofoil. Wing shape and size generally determine a bird's flight style and performance; many birds combine powered, flapping flight with less energy-intensive soaring flight. About 60 extant bird species are flightless, as were many extinct birds. Flightlessness often arises in birds on isolated islands, probably due to limited resources and the absence of land predators. Although flightless, penguins use similar musculature