Birds
Kakapo
Strigops habroptilus · also called kākāpō, owl parrot, night parrot
The kākāpō is a parrot that forgot how to fly. It is nocturnal, moss-green, smells like a violin case, weighs as much as a small cat, booms across valleys to attract a mate, and it very nearly disappeared — every one of the couple of hundred alive today has a name.
Overview
Kākāpō are found only in New Zealand, and today only on a few predator-free islands and inside fenced mainland sanctuaries, moved there for their survival. Historically they were widespread through forests from the coast to the subalpine zone on both main islands. They are nocturnal and ground-based, roosting by day under vegetation or in cavities and foraging at night along a network of well-worn tracks and “bowls” the birds maintain for generations.
An island bird taken to extremes
With no mammalian predators for millions of years, the kākāpō evolved in directions no other parrot did:
- Flightlessness and great size — up to 4 kilograms, the heaviest parrot, with soft plumage and a reduced breastbone keel.
- A long life — likely 60 years and possibly beyond 90, one of the slowest-living birds.
- Infrequent, food-triggered breeding tied to the mass fruiting of the rimu tree.
- A lek mating system — the only parrot with one — in which males gather to display and females do all the parenting.
- A strong, distinctive scent, useful for finding mates in the dark, and disastrous once mammals with noses arrived.
Booming and breeding
In a breeding year, males climb to a ridge, excavate a shallow “bowl” to project sound, inflate an air sac in the chest, and boom — a deep, foghorn-like pulse repeated for hours every night, audible kilometres away, alternating with a higher metallic “ching.” Females travel long distances to a booming male, mate briefly, and return to a nest on the ground, where they incubate one to four eggs and raise the chicks with no male help.
Near-extinction and recovery
Cats, rats, and stoats introduced by settlers found the kākāpō easy prey — it responds to danger by freezing. Numbers collapsed through the 20th century, and by 1995 only about 50 birds were known. In one of the most intensive conservation efforts anywhere, every remaining kākāpō was relocated to predator-free islands, and the Kākāpō Recovery Programme now manages the species almost like livestock: each bird radio-tagged and named, nests monitored around the clock, eggs and chicks fostered or hand-reared, supplementary feeding to induce breeding, and genetic management of the tiny gene pool. The population has recovered past 240, and in 2023 a few birds were returned to the New Zealand mainland for the first time in decades.
Kakapo: common questions
Why can't the kākāpō fly?
It evolved on islands with no ground-dwelling mammal predators, where flight was an expensive luxury it could do without. Over time it became large and heavy, its wings shrank relative to its body, and the keel bone that anchors flight muscles in other birds was reduced. Instead it walks — sometimes kilometres in a night — and climbs trees with its beak and feet, then spreads its wings to glide or "parachute" back to the ground.
What is kākāpō "booming"?
The kākāpō is the only parrot with a lek breeding system. In a breeding year, each male walks to a hilltop or ridge, digs a shallow bowl in the ground that acts as an amplifier, inflates his chest like a balloon, and produces a deep, resonant boom — roughly one per second, for six to eight hours a night, for weeks or months. The low frequency carries up to five kilometres. Females walk in from far away, choose a male, mate, and then raise the chicks entirely alone.
How close did the kākāpō come to extinction?
Extremely close. Introduced cats, rats, stoats, and dogs devastated a bird that freezes when threatened rather than fleeing, and by the mid-1990s only about 50 kākāpō were known, with the last mainland birds and a small Stewart Island population being moved to predator-free islands. Every surviving kākāpō is now individually named, health-checked, and monitored, chicks are hand-reared when needed, and the population has slowly climbed past 240.
Why does the kākāpō only breed some years?
It ties reproduction to "masting" — the years when the rimu and certain other native trees produce a huge crop of fruit, which happens every two to four years. The abundant, protein- and calcium-rich rimu fruit is what females need to form eggs and feed chicks. In non-mast years they simply do not breed. Conservation managers now provide supplementary food to trigger and support breeding more often.