Editing Kākāpō (section)

===Internal anatomy===
[[File:Strigops habroptilus (AM LB299).jpg|thumb|upright|Skeleton]] 
The skeleton of the kākāpō differs from other parrots in several features associated with flightlessness. Firstly, it has the smallest relative wing size of any parrot. Its wing feathers are shorter, more rounded, less asymmetrical, and have fewer distal barbules to lock the feathers together. The sternum is small and has a low, [[vestigial]] keel and a shortened spina externa. As in other flightless birds and some flighted parrots, the [[furcula]] is not fused but consists of a pair of [[clavicles]] lying in contact with each [[coracoid]]. As in other flightless birds, the angle between the coracoid and sternum is enlarged. The kākāpō has a larger pelvis than other parrots. The proximal bones of the leg and wing are disproportionately long and the distal elements are disproportionately short.<ref name="Livezey1992">{{Cite journal |last1=Livezey |first1=Bradley C. |doi=10.1002/jmor.1052130108 |pmid=29865598 |title=Morphological corollaries and ecological implications of flightlessness in the kakapo (Psittaciformes: ''Strigops habroptilus'') |journal=Journal of Morphology |volume=213 |issue=1 |pages=105–145 |date=1992 |s2cid=206090256}}</ref>

The [[pectoralis major muscle|pectoral]] musculature of the kākāpō 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 (anatomy)|crop]].<ref name="Livezey1992"/>