Commonly called the native crow, the kokako does not belong to the crow family, but is, instead, a member of a family of birds peculiar to New Zealand, the Callaeidae, or wattle birds. This family also includes the huia and saddleback.
There are two races of kokako, Callaeas cinerea wilsoni, the blue-wattled kokako, which occurs in the North Island, and Callaeas cinerea cinerea, the orange-wattled kokako inhabiting the South Island and Stewart Island. Apart from the colour of the wattles, which are fleshy lobes hanging from each corner of the mouth, both races are alike in appearance, except that the South Island bird is slightly smaller. Kokako are about intermediate in size between a European blackbird and an Australian magpie, have a predominantly dark-bluish-grey plumage tinged with brown, a jet-black face, and a short, blunt, black bill which is strongly arched. The wings are relatively short, flight is feeble, and the birds progress mainly by a series of bounds on their long black legs. The calls and song are varied and rich and bear some resemblance to the more musical notes of the tui, but are slower, deeper, and richer. A sonorous tolling note and a catlike mewing are especially characteristic.
Food consists of the leaves and fruits of a number of native trees and shrubs. While feeding, the kokako holds leaves and berries in one claw, parrot fashion. Insects are eaten, too. Breeding occurs from November to January. Nests are built in tall shrubs or trees at a height of about 10 ft or more from the ground and consist of a structure of twigs about 18 in. or more across, in the centre of which is a cup-shaped depression of moss and grass some 6 in. in diameter and lined with tree-fern scales. Two or three stone-coloured eggs blotched with dark brown are laid and are incubated by both parents.
The North Island kokako, although much less common than formerly, is occasionally recorded from a number of localities – the Hunua Ranges, Rotorua lakes district, western Urewera, Bay of Plenty, East Cape district, Coromandel Ranges, Northland, and inland Taranaki.
The South Island kokako, though once locally common, is now very rare and there are few reliable recent records either from the South Island or Stewart Island.
The Callaeidae are typically birds of the tall native forests.
by Gordon Roy Williams, B.SC.(HONS.)(SYDNEY), Lecturer in Agricultural Zoology, Lincoln Agricultural College.