Credit: © Brent Barrett
Races including nominate:
|65cm (25.3 in)
||1.5-3.0kg (52.5-105 oz) males; 950g-1.6kg (31.6-56 oz) females
Male-upperparts green with irregular barring and mottling to the plumage, colours black, brown and yellow; underparts green/yellow, irregularly barred pale yellow and brown; yellow/brown facial disc; outer primary feathers tipped with yellow; tail green/brown with yellow barring and black flecks. Bill grey tipped pale grey/white; eye dark brown. Female: smaller in size, with smaller bill; outer primary feathers tipped green/brown.
As in adult but generally duller in colour; forehead and facial disc less prominent and more brown; outer primary feathers pointed, not rounded tips. Bill yellow/white.
Wide variety of squeals, shrieks, sounding like a pig; also donkey-like braying. Repetitious bell sounds. Booming by males during mating season ("lek" display) is repeated 15-20 times at intervals of 2 seconds apiece, continued for many hours.
Recent Academic Research: Google Scholar - search results
BirdLife International http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=1492&m=0
Kakapo Recovery Programme http://www.kakaporecovery.org.nz/kakapointro.html
Parrots: Status Survey and Conservation Plan 2000-2004, Snyder, McGowan, Gilardi and Grajal, 2000.
Parrots: A Guide to Parrots of the World, Juniper and Parr, 1998.
Parrots of the World, Forshaw and Cooper, 1989.
Parrots of the World, Forshaw, 2006.