The kākā (Nestor meridionalis) is a noisy and sociable bird of the forest. It is related to the alpine parrot, the kea (Nestor notabilis).
In 1877 ornithologist Walter Buller wrote of Māori catching 300 kākā a day in the Urewera forest, during the rātā blooming season. Today it is estimated that there are fewer than 10,000 left in all New Zealand, most of them on islands.
North and South island kākā
There are two subspecies, the North Island and South Island kākā.
At 575 grams, the South Island male is 100 grams heavier than his North Island cousin (females weigh 500 and 425 grams respectively). The North Island kākā has olive-brown plumage; the South Island subspecies differs in its brighter green plumage and almost white crown.
The bird’s most common call resembles a creaky door, and it also mimics other species. Kākā can live 20 years, but few reach that age in the wild.
Discovered too late
In 2014 a new species of kākā was discovered – unfortunately, several hundred years after it became extinct. The Chatham Islands kākā (Nestor chathamensis), identified by DNA analysis of fossilised bones, was descended from mainland kākā that found their way to the Chatham Islands 1.7 million years ago. It was about the same size as its mainland relative, but had larger thigh bones, a broader pelvis and a longer beak.
Strongholds for kākā on the mainland include large tracts of forest from the Coromandel Peninsula south to the Aorangi Range in the Wairarapa, and the central North Island forests of Pureora and Whirinaki. In the South Island they are most numerous on the West Coast. On islands without predators, kākā are prolific breeders – after possums were eradicated from Kāpiti Island in 1986, kākā numbers doubled to around 1,000 by 2001. Following their release in the Zealandia sanctuary in 2002–7, they became a common sight in parts of Wellington.
Kākā eat nectar, fruit, berries, seeds, sap, insects and grubs. Enthusiastic feeders, they often leave a trail of debris as they tear out long strips of bark in search of insects and sap. Like honeyeaters, they use their spoon-tipped, bristle-edged tongues to lap up honeydew or nectar from flax and rātā flowers. Often hanging upside down to feed, they become increasingly comical and acrobatic as they get drunk on nectar.
Energy-rich foods are important in bringing the kākā into breeding condition. One reason that breeding has declined, especially in the South Island, is that pests such as wasps and possums compete for honeydew and nectar.
Starting in September (spring), the kākā lays an average of four white eggs in a hollow tree or branch. The chicks take over two months to fledge and another five months to become totally independent. Nesting in tree hollows, they are vulnerable to predators.
New Zealand’s native parrots – the kea, kākā and kākāpō – may have evolved separately from other parrots after New Zealand split off from the Gondwana supercontinent, around 85 million years ago. Kākā and kea belong to an endemic subfamily, Nestorinae.