The kea is a large, strong-flying, olive-green parrot with scarlet underwings and a slender grey-black bill. Sexually dimorphic, female body mass is about 20% less than males and the bill is shorter. Juveniles have yellow ceres and eyelids, which fade to grey as the bird matures.
The commonest call is a long, loud, high-pitched descending cry which may be broken “kee-ee-aa-aa”, or unbroken “keeeeeaaaa”. Many quiet contact calls are given. Juvenile calls are less stable in tone, being more of a loud uncontrolled whooping or squealing.
Kea are unlikely to be confused with other species. Kaka are smaller, olive-brown and very rarely seen above the timberline. They excavate the wood of live trees, whereas keas do not. Kaka have more varied calls, including fluting whistles and harsh grating ‘skraaarks’. The extremely rare and localised kakapo is larger, flightless and nocturnal. It is yellow-green rather than olive-green and lacks a scarlet underwing.