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DON MERTON is possibly the world’s happiest man. For the past 28 years, he has battled to save the kakapo, New Zealand’s extraordinary giant parrot. In 1995, when their numbers fell to 50, it looked like curtains for the “old night bird”. But this year the kakapo staged an astonishing comeback.

The last survivors of this unique and appealing species have produced 26 chicks—more than in the whole of the past two decades. Instead of having no future at all, the kakapo suddenly has prospects. “It’s quite a story,” says Merton, the longest serving member of the National Kakapo Team. “After all the years of blood, sweat and tears it’s fantastic to know that the kakapo is not going to die out in a hurry. In fact, it now has an excellent chance of surviving.”

The kakapo’s swerve from the fast lane to extinction onto the rather slower road to recovery is the result of lavish amounts of tender loving care combined with imaginative research and some inventive technology. From the start, this year looked promising, but the population boom of 39 per cent exceeded even the most optimistic estimates. “We didn’t think we’d ever see anything like this,” says Merton.

Strigops habroptilus is not like any other parrots. It’s nocturnal, it looks like an owl, smells sweet and fruity, and makes some very unparrot-like noises—from growls and “skrarks” to metallic “chings” and deep resonant booms. Kakapo can’t fly, but they are excellent climbers. They live a long time, perhaps more than a century, and are the world’s biggest parrots: adult males weigh in at more than 2.5 kilograms.

The kakapo also has a breeding system unique among parrots and any of New Zealand’s birds. Males gather at a traditional arena called a lek to display and compete for females. After mating, the females head off “home” and raise their young alone. “The kakapo is important because it’s so distinctive, so way-out and different, with combinations of features found in no other bird,” says Merton.

Unfortunately, its peculiarities have also made it extremely vulnerable. Before people reached New Zealand a thousand years ago, there were millions of kakapo. Their only enemies were predatory birds that hunted by sight, and the kakapo’s mottled, mossy-green plumage provided perfect camouflage against the lush vegetation. But these beautiful feathers and the bird’s fine flesh made it a prime target for Maori hunters.

The newcomers also brought dogs and kiore—Polynesian rats—that could sniff out kakapo, homing in on their nests among the roots of trees and other natural cavities. They made short work of eggs, chicks and even adults. The decline in numbers accelerated once European settlers arrived in the early 1800s. They cleared large areas of kakapo habitat and brought more lethal predators—cats, ship rats and Norway rats, stoats, weasels and ferrets, and the Australian brush-tailed possum. By the late 1960s the old night bird was feared extinct.

Then in 1974, after years of searching, Merton and a team from the New Zealand Wildlife Service, forerunner of the government’s Department of Conservation, discovered a single bird in a remote valley in Fiordland in the far south. It was an old male. Search parties scoured the region and found 17 more—all old males. Three years later, when many had written off the species, Merton’s team uncovered signs of kakapo in the south of Stewart Island. It turned out to be a colony of around 200 birds and some of them were breeding. “We thought the kakapo was safe then,” says Merton. They were wrong. Feral cats were killing them at an alarming rate.

What followed was one of the most intensive and expensive rescue operations in the history of bird conservation. Between 1982 and 1997 all the surviving kakapo were moved to island refuges where there were no cats, stoats or European rats. “We thought that if we put them out of the reach of predators they would be OK,” says kakapo biologist Graeme Elliott. They were wrong again. The conservationists hadn’t realised how dangerous the kiore were. Not only did they compete with kakapo for food, they also ate eggs and chicks. Numbers fell further as old birds died and chicks were killed within days of hatching. By 1995 there were only 50 kakapo left.

Merton and his colleagues knew what they had to do. Many of the birds were growing old: they had to breed before it was too late. And once they had, nothing could be allowed to jeopardise their eggs or chicks. From now on, the team would manage almost every aspect of kakapo life. They adopted a zero-tolerance strategy towards kiore, laying traps and watching nests 24 hours a day. If anything other than a kakapo entered the nest, a watcher set off a “rat banger”, a tiny explosive charge that made a small bang and a flash, enough to startle any intruder. By 1999, all the kakapo had been moved to just two islands—Maud Island in the Marlborough Sounds and Codfish Island off the west coast of Stewart Island. Maud Island had never had kiore and they were eradicated from Codfish Island in 1998.

Persuading the birds to breed was harder. Kakapo breed only once every few years when certain native plants produce bumper crops of fruit and seeds, an event known as masting. At other times, the birds get by on a poor diet of leaves and stems, roots and a few berries and seeds. It’s enough to support creatures with the kakapo’s slow metabolism, but not enough to raise a family on. In the past, the kakapo from Fiordland and Stewart Island bred in response to masting by a range of plants—southern beeches, enormous tussock grasses and rimu, a gargantuan conifer that once formed great forests. The kakapo team hoped that if they gave the birds extra food they might breed more often.

“The challenge was to work out a balanced diet and then persuade them to eat it,” says Elliott. The team tried an assortment of fruits, vegetables and nuts and found kakapo were especially partial to walnuts and almonds. The birds thrived on the extra food, but still wouldn’t breed. They seemed to be waiting for some special cue. On Maud Island it wasn’t clear what that cue was but on Codfish Island there was no doubt the birds breed in response to some signal from the rimu tree that alerts them to a coming mast. “It became obvious that if the rimu didn’t mast, they didn’t breed,” says Elliott.

The team had no choice but to wait for nature to run its course. At the first sign the birds might be getting ready to breed, they laid on extra food to ensure the females were in top condition. Later, these food supplements would help the mothers keep their chicks well fed. The team monitored every nest and every egg round the clock. If the eggs were at risk or the chicks failed to thrive, they whisked them away and reared them by hand.

There were setbacks. Some chicks died. But the team learned fast. They discovered that the eggs take 30 days to incubate and that chicks fledge after around 10 weeks, during which time they grow from around 25 grams—the size of a small sparrow—to a hefty 1.5 kilograms. The researchers quickly had hand-rearing down to a fine art. And they discovered that if they removed a clutch of eggs early in the season, the mother would mate and lay again—something that would later prove very useful. Unfortunately, there was a downside to their intensive feeding strategy: fatter females are more likely to produce male chicks. With the population already heavily biased towards males, that was the last thing anyone wanted.

Armed with all this new knowledge and expertise, the team was ready to swing into action as soon as they spotted signs of a coming masting on Codfish Island. Last year, it became obvious that the rimu were going to produce a bumper crop of seeds the next autumn—early in 2002. Merton, Elliott and team manager Paul Jansen decided to capitalise on the event by moving all the adult female kakapo from Maud Island to Codfish Island. By April 2001, all 21 females of breeding age were on Codfish Island. As the breeding season drew nearer, half-a-dozen members of the kakapo rescue team arrived, bringing an assortment of electronic equipment to monitor the birds. Over the next few months they would be joined by a stream of volunteers who would spend long, cold nights watching nests.

In September, the team began to fill up the food hoppers. “We had to provide enough food so that the birds reached the threshold for breeding but not so much that they’d put on too much weight,” says Elliott. “We wanted to keep their weight on the low side to encourage them to produce female chicks.” In December, the males began to boom like foghorns, a nightly ritual designed to attract females from all over the island. The females started to trek up the hillsides to the courtship arenas to choose a mate—unaware that electronic eyes were watching them.

The first pair mated on Christmas Eve, and over the next few weeks every female bar one elderly arthritic bird mated. Each time a pair of kakapo mated, the team trailed the female as she returned to her home patch and began to build a nest. Sometimes a few home improvements were needed. “We make sure the nests won’t flood and they have a decent roof,” says Elliott.

As soon as a female laid an egg, a pair of nest watchers set up camp about 40 metres away. The team had developed a portable “nest kit” over the previous five years, which now came into its own. Each nest soon had its own doorbell—a chime linked to an infrared beam across the entrance. Nesting kakapo make up to five forays for food each night, often staying away for two or three hours. Whenever a bird crossed the threshold, she broke the beam and the bell rang in the watchers’ tent. This was the signal to move in close and set up a miniature video camera to monitor the nest.

While the mother is away her eggs and chicks cool to the surrounding temperature, usually between 0 and 10 °C. Although kakapo are adapted to a cold climate, Elliott thinks the young may be damaged if left too long. So each time a mother left, the watchers covered the nest with an electric blanket—a bizarre invention made from a whoopee cushion filled with wallpaper paste and heated by a battery-powered element. The consistency of the paste ensures that the blanket moulds itself snugly over eggs or chicks. The chicks were also scooped out of the nest for regular health checks using a plastic food sieve on the end of a tele-scopic ski pole. Neither the chicks nor the mothers mind such intrusions. “Kakapo are remarkably forgiving,” says Merton. “They accept almost any sort of intrusion. Many island species that evolved without mammalian predators are like this.”

The kakapo’s laid-back attitude to human interference also meant the team could try some new tricks aimed at boosting the productivity of these ultra-slow breeders. Although all 20 mated females laid eggs, 37 per cent of them were unfertilised. Some infertile clutches were replaced with fertilised ones from other nests, giving the successful birds a chance to mate again and lay a second clutch. The result was four extra chicks. The egg swapping didn’t stop there. Kakapo normally lay between one and four eggs. In the past chicks that hatched last often died, unable to compete with their older siblings. The team decided to even things up so each brood contained eggs of a similar age and no bird had more young than she could cope with. That too seems to have paid off. Of the 26 chicks that hatched, only two have died. A further three are being hand reared but are doing well. “Most wild birds would lose 50 per cent of hatched chicks if they were left to their own devices. We’ve doubled the success rate,” says Elliott. Better still, the feeding strategy seems to have worked: half the chicks are female.

The bumper batch of new kakapo isn’t the only breakthrough this year. Ten-year-old Hoki, the first hand-reared female to reach maturity, mated and laid an egg. “Some people said the hand-reared birds wouldn’t breed,” says Merton. There were fears that they wouldn’t know how to mate or bring up young. But Hoki, who has been something of a celebrity in New Zealand since she hatched, proved them wrong. Although her own embryo died early in incubation, the team swapped the egg for one on the point of hatching, and Hoki was the perfect mother. Another cause for celebration is that even the oldest females, which may be over 50, produced chicks this year. “We thought they might not be capable of breeding. Now we know these birds can breed at a ripe old age,” says Merton.

By anyone’s standards this has been a good year for the kakapo. The young are just beginning to leave their nests and will be independent by November. But there are still only 86 kakapo in the world. What sort of prospects do they really have? The aim of the recovery programme is to build up their numbers until they can safely be left to fend for themselves. “I’m confident that if we keep using the same techniques the population will steadily rise,” says Elliott. “Once there are around 200 birds, we can back off.”

He estimates this could take at least 15 years, less if they can trick the birds into breeding more often. “We’re looking for whatever it is in rimu that triggers breeding. It’s probably chemical—perhaps one of the terpenes the tree is packed with,” says Elliott. “Or it might be nutritional.” The team is about to test an improved food pellet to see if that does the trick. As a back-up, researchers are also investigating ways to promote masting, and trials with plant hormones sprayed onto the trees have boosted productivity a little. “The results were intriguing enough to try it some more,” says Elliott.

There remain some serious questions about the kakapo’s future, however. Species that recover from such tiny populations have little genetic diversity, and that can lead to problems. All but one of these birds comes from a single population on Stewart Island. Yet Elliott thinks the kakapo can cope. He points out that many of New Zealand’s strange birds retreated into tiny refuges during ice ages and made successful comebacks. Others have survived for centuries on little specks of islands. “The problems associated with such genetic bottlenecks may not be so bad here as they are in other places,” he says. Another question is where to put the bird colonies once they outgrow their island homes. Merton has his eye on Campbell Island, 500 kilometres south of New Zealand. It’s big enough for thousands of kakapo, and its last rat was killed this year.

In 1990, I wrote an article for 91av which asked “Can anyone save the kakapo?” Back then, it looked as if nothing short of a miracle would rescue the species from extinction. Today, it seems the kakapo team has achieved the impossible. “They were undoubtedly heading for extinction and were very, very close,” says Merton. This new generation has given the species a new lease of life. “No matter what the birds do now,” says Elliott, “they won’t be extinct in our lifetimes.”