There is no specific name for this physiological feature of the kakapo. It is simply called an inflatable thoracic air sac.
Kakapo is the Maori name. It means "night parrot".
alveoli
air sac
the air sac itself.
it optain air by when it goes over water
The scientific name of the only remaining takahe, the South Island takahe, is Porphyrio hochstetteri.
Carbon dioxide
An alveolus is a single air-sac, and alveoli are multiple air-sacs.
It is easy for air to pass across the wall of an air sac because the wall is thin.
The biological term for an air sac is "pneumatic sac," which refers to a structure in the respiratory system of certain animals that aids in breathing by storing or regulating air flow. These structures are commonly found in birds and some reptiles.
Alveoli is an air passage
Air sac