Strangers from paradise
What is a brightly coloured parakeet whose nearest ancestors live in the tropics, doing in the company of penguins in the subantarctic? Kakariki, New Zealand’s endemic parakeets, break all the rules.
The rain thundered down as we approached South Bay on Antipodes Island. Towering hundreds of metres above us and shrouded in fog were volcanic cliffs made up of layers of solidified lava and ash.
This was where Jerry Clark and Roger Sales lost their lives when the Totorore was wrecked in 1999, en route to collect an albatross research team stationed on the island. And this rock outcrop, deep in the Southern Ocean, is a place I’d been longing to visit ever since I was a kid. Bruce Thomas, a biologist from Landcare Research, had regaled me with stories of pioneer rat eradication programmes and making Adelié penguins vomit for science. Those stories set me on a course of science I have followed ever since, and reaching the rocky cliffs of the Antipodes was like realising a dream.
Though this hostile place is of personal significance, its real value is scientific. Inside the wide moat of the Southern Ocean, and behind the impenetrable barricade of its basalt walls, the Antipodes yields important clues on the evolution of New Zealand flora and fauna, and its preservation.
Anchoring in the lee of the Windward Islands, on the western side of Antipodes Island, we boarded an inflatable dressed in full wet weather gear. As we motored quietly ashore, wandering albatross soared above us, Southern elephant seals lounged on rocks and the sounds—and odours—of colonies of eastern rock hopper penguins filled the air. Then, flying high on the cliff face above us was one of the birds I’d come all this way to see and study, an Antipodes Island green parakeet, the largest and most southern of our native kakariki.
It’s worth pausing for a moment to consider the significance of this sight. Kakariki are a very modern lineage stemming from the Australasian platycercine parrots, a group that includes the rosellas and rainbow lorikeets, as well as the shining parrots of Fiji—tropical and warm temperate residents all. So what on earth is a coloured parrot doing in the company of daub seabirds on a sub-antarctic island at nearly 50º south?
To unravel this enigma we need to travel back up north to the ancient southern beech forests of the New Caledonian archipelago, and back in time some 2.3 million years. Genetic analyses suggest that it was here that ancestral platycercines split into two lineages. The first survives as the horned parakeet and Ouvea parakeet on New Caledonia, and the second was the ancestral kakariki—the New Caledonian red-crowned parakeet is, as far as we know, the most primitive of all kakariki.
Most parrots generally don’t like to cross large distances of water, but 625,000-400,000 years ago something extraordinary happened, something that would prompt a tropical parrot to fly to New Zealand and the subantarctic. A mix of environmental conditions aligned to create a mast event—or simultaneous fruiting of one or more species of trees. The abundance of food produced would have allowed kakariki to breed successfully during winter months, dramatically increasing parakeet numbers. But in subsequent years without mast events, the food supply would have collapsed under the population, resulting in ancestral kakariki dispersing in all directions in search of alternative food sources.
Red-crowned parakeets, and to a lesser extent yellow-crowned parakeets and orange-fronted parakeets, colonised the near and offshore islands, including the Subantarctic and Kermadec Islands. It was an ancestral red-crowned parakeet that colonised the Antipodes Island which, in isolation, evolved into Antipodes Island green parakeet. It lost its red crown, instead adopting a gentrified plumage of emerald green and royal violet-blue.
A Female Antipodes Island green parakeet chat‑ters in my hands as I weigh and measure her. The boisterous males I was holding earlier lacerated my fingers with their beaks, but she is more docile, swivelling her head and looking at me with deep, black eyes. She is strikingly beautiful. Not dowdy, like a lot of NewZealand’s native birds, but deep emerald green, and much darker than her mainland cousins. Running through the emerald green plumage on her wings are flashes of deep royal blue.
Our kakariki are fearless, inquisitive, animated, cheeky and intelligent, traits they share with the kea and kaka. I have observed a large group of red-crowned parakeets taking turns sliding down the corrugated iron roof of the Department of Conservation shed on Matiu Somes Island in Wellington Harbour, chattering loudly like children in a toboggan. May and Russell Evans, who manage the captive breeding programme for the Antipodes Island green parakeet, say they will waddle and hop up your arms, or steal tools you leave lying around. And like kea, they will tear your tent apart given half a chance.
This evident intelligence is probably one factor that contributed to their survival in such hostile conditions. Their size, appearance, hunting and dietary preferences are now well-adapted to life in the subantarctic, and attempts to breed this species in the humid, hotter northern regions of New Zealand have resulted in declining health, disease and even death.
But the miraculous presence of a parakeet descended from tropical ancestors in a subantarctic environment is barely the beginning, for it also exposes a myriad of other questions of scientific significance. For while the evolution of its mainland cousins has been interrupted by the arrival of humans, the evolution of the Antipodes Island green parakeet has not, and goes some way towards answering my central research question: What were kakariki like during pre-human times?
We know that yellow-crowned parakeets, red-crowned parakeets and orange-fronted parakeets inhabited forest and shrubland/grassland areas throughout the mainland, many of which were regularly journeying to and from near-shore and offshore islands. They were part of a fauna dominated by birds, with the top predators in the ecosystem birds like the now extinct Haast’s eagle and Forbe’s harrier. Fossil bones tell us that kakariki were common throughout New Zealand, and likely to have been predated on by birds such as the laughing owl.
They were still actively speciating at the time of the Polynesian arrival in about 1280 AD—when there were 12 species and five subspecies distributed from the Society Islands to the north east of New Zealand to Macquarie Island in the south, and from Lord Howe Island in the west to the Chatham Islands in the east. Fossil remains of an extinct Campbell Island kakariki have been recently discovered in a cave that was also once occupied by wartime coast watchers—the chairs and teabags are still there on the floor of the cave. More recently, fossil remains comparable to kakariki have also been discovered in a cave on Rapa, in the Austral Islands.
While the majority of kakariki nested in tree hollows high in the canopy, the Antipodes Island green parakeet nested in burrows under tussock (some of which would have been abandoned seabird burrows), because it’s too cold and too far south for any trees to grow. Reischek’s parakeet, also on Antipodes Island, nested in the crown of tussocks or ferns.
Kakariki ate mainly seeds, fruit and insects but also would have scavenged and predated, especially on isolated islands. When goats were eradicated from Macauley Island in the Kermadec archipelago, kakariki were seen feeding on the carcases, and the Antipodes Island green parakeet have been seen digging storm petrel chicks out of their burrows and devouring them. While the diets of different kakariki overlapped, foraging techniques did not. Yellow-crowned parakeets foraged in the canopy while red-crowned parakeets foraged on the ground. This would have made the latter extremely vulnerable to predation by introduced predators, and partly explains why it became so rare on mainland New Zealand. On Antipodes Island, Reischek’s parakeet and Antipodes Island green parakeet effectively divided the island in half, to avoid competition for resources. Antipodes Islands green parakeets preferred the steeper coastal slopes, while Reischek’s parakeet preferred the central plateau.
But the evolutionary trajectory of kakariki, along with New Zealand’s other avifauna was shattered when Polynesian settlers arrived in New Zealand. The result was the extinction of 41 per cent of New Zealand’s avifauna, including our largest birds—moa, Haast’s eagle, adzebill and a goose—plus the local extinction of seal populations around New Zealand, all within about 100 years.
While the literal meaning of Maori legends are obscure, they suggest that kakariki were never held in high regard. The name often used as a derogatory term and associated with bad omens. “He kakariki kai ata”—or “a kakariki who feeds at dawn”—was used to describe someone who ate breakfast straight after waking up, like the kakariki, instead of doing work and eating later as was custom.
Kakariki were hunted by Maori and were probably easy to catch. Early explorers on the Kermadec Islands noted that they could walk up to one and drop a hat over it. The bird’s demise was exacerbated by the burning of forest in New Zealand by Maori to facilitate easier travel and moa hunting, and the introduction of mammalian predators like kiore, the Polynesian rat, and kuri, or Maori dogs, both of which predated on kakariki.
However, when Europeans arrived in New Zealand in the late 1700s and early 1800s, there were still plenty of the birds, as Sir Walter Buller noted during his travels. This was also the time that kakariki were being discovered by the international scientific community and became the subject of considerable debate around the taxonomic status of the bird, a debate that continues today. Scientists have been divided, for instance, on whether the orange-fronted parakeet is a colour morph (a race of bird) of the yellow-crowned parakeet, or a completely different species. It was originally described as a distinct species, was later synonymised with yellow-crowned parakeets based on hybridisation experiments, while more recent genetic and ecological evidence has elevated it to full species status, as the sister species of Reischek’s parakeet.
At one stage the kakariki’s popularity as a caged bird (they were hardy and prolific breeders) was so high they rivalled the popularity of budgies. Early Victorian collectors seem to have favoured the Antipodes Island green parakeet as a caged bird, while their French counterparts preferred the orange-fronted version.
But by the late 1800s, kakariki were considered a pest in rural New Zealand. This was due to large irruptions—or plagues—of kakariki descending from the wooded hill country into cultivated districts, as a result of forest fire, or collapses in food sources following mast events. They would have arrived lean, covered with parasites and extremely hungry, sometimes followed by plagues of rats.
These plagues were especially common in the South Island, with massive flocks of birds arriving to feast in orchards and wheat fields. In the 1880s fruit farmers in the Moteueka district offered sixpence for a dozen kakariki beaks. One such plague resulted from a fire in the Oxford forest, with kakariki reaching Christchurch city, where some were shot from the roof of the Canterbury Museum. Records from the North Island are somewhat scarce, though the few that exist indicate that they were also considered a pest by early settlers in the Hutt Valley. Miners of the day would have disagreed, as they regularly dined on parakeet pie, which they described as “very good eating”.
The situation was somewhat different in the towns and cities. Sir Walter Buller remarked that red-crowned parakeets were the Pretty Polly of the family, and were often housed in homemade cages made from candle boxes or whisky crates, which could be seen affixed to the sides of houses in Porirua and Kelburn, Wellington. Some of the settlers in those days would have been sleeping on mattresses stuffed with kakariki feathers as well.
But the numbers of parakeets crashed after the last plague in 1886 and never recovered. By the early 1900s red-crowned parakeets were rare in many mainland areas but common on near and offshore islands, yellow-crowned parakeets were restricted to tall stands of old established forest on the mainland and near shore islands, and orange fronted parakeets to southern beech forest in Canterbury and Nelson districts. The distribution remains much the same today.
The situation was similar on the offshore islands around New Zealand. By the late 1700s to late 1800s, the Macquarie Island red-crowned parakeet, the Campbell Island parakeet, the Lord Howe Island parakeet, the black-fronted parakeet and Society parakeet were extinct. It is not known when the Tuamotu parakeet became extinct. On the Auckland Islands (where kakariki numbers were relatively low) habitat modification resulted in widespread hybridisation. As a result, the yellow-crowned parakeet is all but extinct there. The same is happening on Mangere Island in the Chathams, between Forbes’ parakeet and Chatham Islands red-crowned parakeet. Only the parakeets on Antipodes Island have escaped relatively unscathed.
Farther north however, the situation is better. The Kermadec Island red-crowned parakeet, which survived the volcanic eruption of 2006 (on Raoul Island), has a population of some 10,000 individuals. And now that kiore have been eradicated from Macauley Island, the Kermadecs can join the growing list of pest free islands in New Zealand, making the bird’s future even brighter.
So, with all this in mind, what is the likely future of the kakariki? Global extinction would be the final word—there is no coming back from that—and for numerous kakariki taxa, this has already happened. And while local extinction isn’t the end of the matter, it does alter the evolutionary trajectory of a species. Island populations have and will continue to rapidly diverge into new subspecies and future species. Kakariki populations on islands such as Tiritiri Matangi and Kapiti Island will become genetically distinct from other island populations, as has already been seen in green geckos and kiwi. And local population declines also result in the loss of genetic diversity which, in the long term, leads to inbreeding depression, as is currently affecting the kakapo population.
Near and offshore pest-free islands such as Wellington’s Kapiti Island, Matiu Somes Island and Mana Island and Tiritiri Matangi in the Hauraki Gulf, offer the best hope for the kakariki. On Mana Island, recently transferred yellow-crowned parakeets (from Chetwodes in the Marlborough Sounds) are thriving and the population rapidly increasing—even if the majority of the kakariki nest boxes were used by starlings during the breeding season. And on Matiu Somes Island, the red-crowned parakeet population is exploding and turning up in Eastbourne just across the harbour. Captive breeding programmes for the Antipodes Island green parakeet and orange-fronted parakeet are providing a vital role in establishing safeguard populations and preserving the genetic diversity of the wild populations.
Far from Antipodes Island where we started this story, I was cruising along the shore of the Meyer Islets in the Kermadecs, some 1000 km north east of North Cape. The sun was sinking behind Raoul Island, its rays highlighting the fine volcanic ash that was still in the air from the Green Lake eruption a few days before. Thousands of sea birds were wheeling above my head, returning to their roosts after a day of fishing. I could faintly hear the chattering of Kermadec Islands red-crowned parakeets over the cacophony of sea birds which are beginning to return to Raoul Island, after an absence of over 150 years. It occurred to me that this must have been something like New Zealand was before it was settled by humans. Whether we manage to recreate some of the qualities of the Kermadecs on the mainland, with colourful parakeets again flying around our southern beech forests, will depend on what we do now.