Kaka

Overview

The Kaka (Nestor meridionalis) is an ancient, charismatic, and raucous forest parrot endemic to the temperate rainforests of New Zealand. Belonging to the endemic superfamily Strigopoidea—an archaic parrot lineage that split from all other global psittacines approximately eighty million years ago during the breakup of the supercontinent Gondwana—the kaka is the forest-dwelling sister species to the alpine Kea (Nestor notabilis). Draped in a stunning plumage of olive-brown and crimson-ruby, and renowned for its vibrant, ringing whistles and clownish aerial acrobatics, this intelligent bird is a quintessential symbol of Aotearoa’s primeval avian fauna.

Occupying a crucial ecological role as a high-canopy pollinator, seed disperser, and excavator of ancient trees, the kaka possesses a brush-tipped tongue adapted for licking nectar and scale-insect honeydew, paired with a massive, razor-sharp bill capable of tearing open rotting hardwood trunks to extract wood-boring beetle larvae. Historically widespread throughout both main islands, the species suffered catastrophic declines following European colonization due to rampant deforestation and devastating predation by invasive mammalian carnivores, particularly stoats and brushtail possums. Today, thanks to intensive pest eradication on offshore islands and fenced mainland sanctuaries, the kaka is staging an inspiring, celebrated recovery.

Biology and Physical Characteristics

Morphologically, Nestor meridionalis is a medium-sized, stocky parrot distinguished by subtle yet gorgeous coloration. Its body plumage is predominantly olive-brown laced with dark feather margins, complemented by a pale silvery-grey crown, warm orange-gold cheeks, and a brilliant, glowing scarlet-crimson mantle across its lower back, rump, belly, and underwing coverts that flashes spectacularly during flight. Two recognized subspecies exist: the North Island kaka (N. m. septentrionalis), which is slightly smaller and darker, and the South Island kaka (N. m. meridionalis), which exhibits brighter crimson highlights and a whiter crown.

The kaka’s bill is an evolutionary marvel: exceptionally long, strongly decurved, and armed with a chisel-like lower mandible that functions as an organic crowbar. The bird uses this bill to strip thick bark and gouge vertical feeding trenches into living trees, such as beech and rata, tapping into vascular cambium to drink sweet, nutrient-rich phloem sap. Its tongue terminates in a fine brush of keratinized papillae that efficiently laps up liquid nectar and sweet honeydew droplets excreted by native scale insects (Margarodidae) infesting beech trunks.

Behavior and Ecology

Kaka are gregarious, highly social, and vocal birds that maintain active family groups and loose foraging flocks. They are famous for their playful antics and crepuscular habits, often remaining active long after sunset and during bright moonlit nights, filling the forest canopy with a chorus of harsh grating calls, musical whistling notes, and booming chortles. In flight, they execute daring maneuvers, rolling upside down, tumbling through canopy clearings, and soaring high above the tree line.

The species is an obligate cavity nester, relying entirely on deep, natural hollows in ancient, living or dead canopy trees—especially large podocarps like totara and rimu. Breeding is tightly synchronized with mast seeding events of native beech and podocarp trees, which produce massive crops of fruit and seeds every three to five years. Females lay clutches of two to five white eggs directly onto rotting wood mulch at the base of the tree hollow. The female performs all incubation over a 24-day period, during which she is fed entirely by her mate; unfortunately, this habit of nesting in deep, ground-accessible tree hollows leaves incubating females and helpless chicks extraordinarily vulnerable to introduced mammalian predators.

Conservation and Human Impact

The Kaka is evaluated as Vulnerable on the IUCN Red List of Threatened Species, reflecting substantial historical population contractions that eliminated more than ninety percent of its pre-human numbers. The introduction of stoats (Mustela erminea), ship rats, and brushtail possums proved catastrophic, with stoats routinely entering nest cavities to kill brooding mothers and devouring chicks, leading to severely skewed adult sex ratios heavily dominated by surviving males.

Conservation interventions orchestrated by the New Zealand Department of Conservation (DOC) and community trusts have triggered a remarkable turn of fortune. Large-scale aerial predator control operations using biodegradable 1080 poison, automated trapping networks, and predator-proof fenced reserves—such as Zealandia Sanctuary in Wellington—have enabled kaka populations to boom. In Wellington, kaka have expanded from sanctuary boundaries into suburban gardens, city parks, and backyards, marking one of the world’s most successful urban wildlife reintroduction milestones.

Interesting Factoid

Kaka act as forest engineers by gouging horizontal grooves into living tree trunks with their pickaxe-like lower beaks to create ‘sap taps,’ returning days later to drink the sweet flowing sap and lap up the sugary honeydew excreted by insects attracted to the wound.