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"
Kakapo long and the distal elements are disproportionately short. The pectoral musculature of the kakapo is also modified by flightlessness. The pectoralis and supracoracoideus muscles are greatly reduced. The propatagialis tendo longus has no distinct muscle belly. The sternocoracoideus is tendinous. There is an extensive cucularis capitis clavicularis muscle that is associated with the large crop. Because kakapo passed through a genetic bottleneck, in which the world population was reduced to 49 birds, they are extremely inbred and have low genetic diversity. This manifests in lower disease resistance and fertility problems: 40% of kakapo eggs are infertile. Beginning in 2015, the