The first bullet ripped through his skin and lodged in the side of his skull. The impact temporarily froze his right hand, but he was still alive. Intent on doing himself in, he twisted the cold barrel perpendicular to his head and again pulled the trigger. This time the gun misfired. Providence? He put the gun down.
Until that lonely night in Mt Eden, Auckland, in 1893, when the “black dog” moods overpowered him, Richard Henry had always been soothed by the Fiordland wilderness. He had spent a decade observing the patterns of life around him in the temperate rainforest and recording their demise. He had built a following among readers of the Otago Witness with his accounts of the day-to-day dramas of flightless birds. The embryonic conservationist community had recognised his rare talent as a field naturalist and communicator and nominated him as their preferred candidate for conservator of Fiordland’s newly reserved Resolution Island.
Henry had thus become entangled in the combative back-room politics of colonial New Zealand. A growing minority viewed the native flora and fauna as valuable and worth preserving, but they were hamstrung by a plodding bureaucracy. Policy and politics were unfamiliar territory to 48 year-old Henry, whose frustration at powerlessness exacerbated depression brought on by physical deterioration after years of hard physical toil.
While waiting for government funds that would allow him to become established as curator of Resolution Island, Henry tidied up his affairs. He left his small pole house in Te Anau and set out to raise scientific interest in his theories on kakapo breeding. Because he wasn’t scientifically trained and didn’t follow the conventions, or use the language, of science, scientists didn’t know what to make of his extraordinary observations. He felt humiliated by their rejection. Of Frederick Hutton, professor of biology at Canterbury College and curator of Canterbury Museum, Henry observed: “…he thinks more of a classical name than about a curious and wonderful fact. He seemed not to take a bit of interest in my story about kakapos but was very anxious to explain to me some straw-splitting difference that shifted a bird out of one class and into another.”
That night in Mt Eden, Henry felt he had outlived his usefulness. “It was purely a personal matter and when I was not in good working trim it was of no matter to anyone,” he later wrote to his friend Edward Melland, a well-connected Dunedin businessman and conservationist. “You know we all have to clear out and I think it a privilege to have the choice of how, where and when.”
Eight hundred years ago New Zealand was home to the most extraordinary collection of birds. There was nothing like it anywhere else in the world. The fossil record reveals that after New Zealand had been cast adrift from Gondwana, birds radiated so as to fill the ecological niches mammals came to occupy elsewhere. As the Australian biologist Tim Flannery writes in The Future Eaters, “Nowhere else had birds evolved to become the ecological equivalent of giraffes, kangaroos, sheep, striped possums, long beaked echidnas and tigers.”
The thoughts of the first humans to arrive on New Zealand shores were not of preservation but of food and survival. Aboard the waka that brought Polynesians to Aotearoa were the edible passengers kiore and kuri—rat and dog—and they brought extinction to many native animals. The largest frogs, tuatara, and a number of smaller birds and invertebrates couldn’t handle the predatory pressure and were soon lost from the mainland. Sea lions were once found all around the coast, but hunting exterminated them, as it did the 11 species of moa. Haast’s eagle and the great goshawk also disappeared. Equally damaging was the firing of forests. By 1840, roughly half of the country’s original forest cover had gone up in smoke. As a result of both predation and habitat loss, 32 species of bird—out of a total of 129—became extinct in the 600 years of pre-European Polynesian/Maori settlement.
Nevertheless, by the latter half of this period (1500–1800), notes historian James Belich, there had been a shift in Maori behaviour, an “extractive” economy giving way to a “sustainable” one. But, unlike 19th century Maori, who, half a millennium on from their colonising ancestors, had learned to manage the land without causing further severe ecological damage, early European settlers had little regard for their new country’s native fauna and flora. In general, Pakeha took a fatalistic approach to the decline of indigenous species. Their crops, farm animals and agricultural technology took precedent; extinctions were to be expected, in accordance with the “inevitable law of displacement”, as New Zealand was fashioned into the “Britain of the South”.
The demise of native species was accelerated by the spread of acclimatisation societies through Victorian New Zealand and the host of exotic species they imported. After early attempts to introduce rabbits had failed, acclimatisation societies undertook a more rigorous and coordinated release in the early 1860s, and by the second half of the decade rabbits were spreading uncontrollably through the South Island. While the occasional critic of the unfettered introductions of the time was to be found, most people were in favour. Notable among the critics was Nature, a British scientific journal as esteemed in the 19th century as it is in the 21st, which described the enthusiastic embrace of acclimatisation as a “silly mania”, deplored the “reckless way animals of extremely doubtful advantage have been transported to the Antipodes”, and concluded that “the importations will become the greatest nuisance”.
These words would prove prophetic, but practical pioneers did not spare a lot of thought for the damage they were doing. Those busy breaking in the land could not afford to romanticise the landscape—it represented food, shelter and money. The conversion of forest to farm put pressure on native species, but it gave the new owners of the land a sense of belonging that few of them had experienced before coming to New Zealand. Arthur S. Thomson, author of an early history of New Zealand, summed up this sentiment when he wrote, “Every man loves the spot of ground he reclaims from the wilderness better than the place of his birth.”
Only a small number of the new New Zealanders thought the special qualities of New Zealand were worth conserving. This conservationist impulse was generally confined to the educated, well-heeled and thick-skinned. Canterbury gentleman, runholder, MP and amateur ornithologist Thomas Potts was such a man. The Encyclopaedia of New Zealand describes Potts as “A brisk, peppery, extremely strong, little man, witty and congenial.” He needed all his pluck, for he was constantly rubbing up a bristly establishment the wrong way.
In 1868, in what is generally regarded as the first conservationist speech in the New Zealand parliament, Potts called on the government to “ascertain the present condition of the Forests of the Colony, with a view to better conservation”.
Potts didn’t really enjoy politics; “his heart was in his hobbies—ornithology, entomology, and botany”. But he, more than most, understood the fragility of the native birds and despaired at the apparent lack of interest in their plight. He resolved to do something about it. In the first issue of the Transactions and Proceedings of the New Zealand Institute, he aired his theories on the danger he considered the birds of New Zealand to be in and suggested ways to protect them. Most people, however, were only interested in looking after introduced game birds they could hunt.
Potts also criticised the attitude of collectors and scientists:Bird dealers, agents and collectors for museums, are not as a rule troubled with any scruples as to times and seasons in which their spoils may be obtained; winter and summer plumage, sexual distinctions, immature and adult forms, are each in their several states attractive to collectors.
You are not expected to speak out on this subject of bird slaughter, you are numbered with the philistines if you murmur at wounding and maiming in the interests of museums; mortal offence was said to have been given by an indiscreet individual who recorded the fact that one collector alone had killed and disposed of 2000 specimens of the harmless kiwi.
Neither did the blunders of the powerful acclimatisation societies escape his attention.It would not be a matter of much regret if the present irresponsible system of acclimatisation be stopped before mistaken zeal results in further errors.
The idea of preserving remnants of the original New Zealand for future generations began to take shape in the 1860s and 1870s. According to Paul Star, a conservation historian at Otago University, Potts suggested in his seminal essay National Domains that large tracts of land should be set aside to be used as refuges for vulnerable native animals and plants. He also hit on the idea of converting islands still free of introduced species into refuges.
In 1872 Potts wangled himself a trip on the government steamer round the bottom of the South Island to Fiordland. The remoteness and vastness of Resolution Island struck him as fulfilling the practical requirements of an island sanctuary. “Later that year,” Star comments, “Potts proposed that both D’Urville Island, in the Marlborough Sounds, and Resolution Island, in Dusky Sound, ‘might be placed under tapu from molestation by dog and gun’, so that ‘wingless species, and birds of feeble powers of flight, might there find a refuge for some of their representatives’.”
By the mid-1870s the rabbit liberations had begun to bite where it hurt most—in the pockets of sheep farmers. Instead of reviewing the “silly mania” of introducing species of “doubtful advantage”, farmers cast their net in search of a “natural enemy”. Many were facing ruin and they formed a powerful lobby. The biological controls they sought were mustelids—stoats, weasels and ferrets.
The day after the request to introduce mustelids had been made, George Grey stood up in Parliament and recommended that stoats, ferrets and weasels be added to the list of “prohibited animals”. The farming lobby, however, had the political clout to repel the pot shots of a small group of conservationists. Captain Fraser of Otago represented the majority when he said he was “very fond of birds; but if it came to a question whether he would have birds or sheep, he would certainly vote in favour of the sheep”.
The first heavyweight scientist to enter the debate was Professor Alfred Newton, of Cambridge University.His comments were quoted in the Otago Witness in December 1876, as: the avifauna of New Zealand, regarded from whatever point you choose, is the most interesting, as it is the most peculiar, in the world, and those who would knowingly compass its extinction, must be deservedly held to blame… You may say that the New Zealand fauna is already doomed, and indeed I fear that the greater part of it will become extinct; but we know not which, or how many of its members may be preserved, if some care or consideration be shown towards it.
Newton urged prominent New Zealand scientists and ornithologists—men such as Walter Buller, James Hector and Frederick Hutton—to use their influence to prevent the introduction of predacious animals. But they either did not support him or put forward only weak objections that caused few ripples. Most objections came from the other side, and continued to be concerned with the protection of newly acclimatised game birds, on which a fortune had been spent.
Newton attempted to shame Frank Buckland, the self-proclaimed naturalist who was collecting the mustelids to export to New Zealand, and his attacks on the man proved more successful than his protests to the New Zealand parliament. Buckland agreed to “pause a while” and place the matter before the New Zealand authorities. But the government ignored all pleas and scientific warnings, and in 1882 government-supported shipments of ferrets, stoats and weasels arrived on the country’s shores.
“The eventual introduction of mustelids,” summarises Star, “represented the victory of landholders’ desperation over scientific foreboding, and of income over the environment.”
Nonetheless, in the 1880s native emblems of New Zealand began to appear in popular culture. Most notably, perhaps, the members of the 1884 national rugby team wore a golden fern leaf on their playing jerseys. It was symbolic of the beginning of a new identification with the land.
Irish born and Australian-raised immigrant Richard Henry had arrived in New Zealand in the 1860s. A man who identified with the land of his adopted home, he took a job as a farm hand on Te Anau Downs station and became a jack-of-all-trades: hunter, collector, sawmiller, rabbiter and boat-builder. Edward Melland, owner of Te Anau Downs and member of the Otago Institute, befriended Henry. The two men shared conservation philosophies and took numerous excursions into the outdoors together. When Henry discovered a complete takahe skeleton in a small patch of scrub close to his home in Patience Bay, Melland brokered a deal to sell it to the Otago Museum, where it can be found today.
Melland recognised Henry’s tremendous feel for nature and encouraged him to publish accounts of his observations and encounters. The kakapo, a comical, bowling-ball-sized, tree-climbing ground parrot, found aparticular place in Henry’s narratives: Once when without a dog I met one sitting on a stick under a fern a few feet from the ground, and went up to have a talk with it. It looked at me more in wonder than fear, until I chucked it under the chin, when it assumed a fierce attitude and protested in its hoarse voice, but made no attempt to go away, and when I let it alone a few moments it coolly put its head under its feathers and went to sleep again.
In another story Henry described how one evening near his camp he watched an excitable weka thrash a kakapo which was “so fat from eating tender broadleaf shoots that it could barely toddle to safety”. He was struck by the amiable bird’s defencelessness: “…they are the easiest things in the world to exterminate. A few wild dogs would clear the country in a decade.”
As Henry’s confidence grew, he wrote a semi-autobiographical pamphlet, The New Zealand Rabbit and its Prey, under the pseudonym An Old Acquaintance. This was a story about his dealings with rabbits, told from a runholder’s and rabbiter’s perspective in the form of an allegorical tale, which lampooned the mistakes of acclimatisers and rationalised the frustrations of farmers: “I invested in exterminating machines that soon exterminated my patience…then I invested in natural enemies.” Henry went on to clinically undress the justification for introducing mustelids:
The real natural enemy of any animal, is that which removes its food… Our sheep runs in their barrenness of resources other than rabbits, are opposite as the poles to the native haunts of the mustilidae; and our evidence is against the probability of their being able to subsist exclusively on rabbits (supposing they could catch them), so that when they finish up the few larks, lizards and wekas, they will look around a little.
He elaborated on his argument that the runholders were deluding themselves if they thought ferrets, stoats and weasels would control rabbits, and concluded that the introduction of these animals was likely to be an aggravation of the evil it was intended to cure.
Similar sentiments were beginning to be expressed elsewhere. In 1882, opinion in the Otago Acclimatisation Society still ran slightly in favour of mustelids, but by 1884 it had belatedly swung strongly against. Collectively, the Otago society expressed “deep regret” that mustelids would “in all likelihood destroy Maori hens [weka] and other native birds”. As Star notes, “concern for native birds, only a secondary argument in 1882, had by 1884 become the main argument against the mustelids”.
Indeed, it wasn’t long before Henry noticed that weka numbers were shrinking. In a letter to the Otago Witness he wrote, “In 1884 I counted 16 wekas at Te Anau Downs…and now they are gone.” And after the weka, the ferrets demolished the ducks: “I have known the ferrets to take seven young paradise ducks out of a clutch of 10.”
From his regular forays across Lake Te Anau, Henry was the first to report the decimation on the unpopulated west side of the lake: “From the mouth of the Waiau for 25 miles of beach, there are neither signs nor sounds of kakapo, weka or kiwi…but there are plenty of ferret tracks.”
Henry believed there was no stopping the onslaught and the only solution was to create safe havens for kakapo and kiwi on remote islands. “On the islands the birds may survive for half a century,” he wrote, “and by that time people in every corner of the world will realise their interest and value, and then there will be no fear of their becoming extinct. If we had a pair of live dodos now or even a pair of takihis they would be valued at almost their weight in diamonds…”
At much the same time, Gerhard Mueller, the chief surveyor of Westland, while looking for a new route for a railway line from Wanaka to the West Coast, caught weasels and ferrets just north of Jackson Bay. He deduced they must have crossed the Southern Alps, and, since there were no rabbits in Westland, predicted mustelids would complete the “extermination of our ground-birds”.
“A wingless species stands no chance whatever in the face of stoats, ferrets and weasels,” agreed Buller, New Zealand’s most famous ornithologist. “Experience had shown that expiring species always lasted longest on islands, and we ought to draw a lesson from experience and place the native birds on islands.”
By now New Zealand’s ecology was totally out of whack, explains Star. “Henry, Mueller and Buller had all indicated that the presence of mustelids in the bush could wipe out entire bird populations in a matter of months. So there was a real urgency at the 1891 meeting of the new Australasian Association for the Advancement of Science held in Christchurch, and most of the delegates swung in behind the idea of establishing island sanctuaries.”
John McKenzie, the minister of lands, acted swiftly after some back-room arm-twisting by Buller and Lord Onslow, Governor of New Zealand. Within a few weeks Resolution Island had been designated the world’s first island sanctuary for native animals. The call had gone out that native fauna must be protected at once, and government had listened to the people.
Jubilation was premature, however. For nearly two years delegations met and argued with the government. One of the main points of contention was the suitability or otherwise of Resolution as a refuge. Competition was coming from Hauturu/Little Barrier Island. Henry Wright, a businessman who had built his fortune on the back of refrigerated-meat exports, was one of conservation’s more unlikely characters, but he convincingly argued that Little Barrier had advantages over Resolution as a bird sanctuary. It was both warmer and out of swimming range of predators. Ngati Wai owned the island at the time and were not keen to leave; nonetheless, in January 1893, the colonial secretary declared that the government had decided to secure Little Barrier as a refuge rather than appoint a curator for Resolution.
George Thomson, a member of the Otago Acclimatisation Society, had twigged that Wright’s claims were behind the withdrawal of support for Resolution Island. Driven by the urgency of saving native birds, or perhaps indignation, Thomson convinced Dr Hocken, the president of the Otago Institute, to join forces with the acclimatisation society.
A delegation of Otago’s heavy-hitters, including Melland and professor of biology at the University of Otago T. Jeffery Parker, descended on Wellington while Henry waited to meet Thomas Cheeseman, the curator of Auckland Museum, to talk about kakapo with him. Parker and Melland pointed out the need for two sanctuaries because of the great diversity in species to be protected and the different climates of the two locations. They also stressed their belief that the narrowest point along Acheron Passage, between Resolution Island and the mainland, would “prove a most effective barrier” to predators, including mustelids.
In Henry’s own words, the thing that stopped him pulling the trigger a third time was that “the remnants of superstition made me think I had better put it off to see what would turn up”. What turned up was the job he had been craving. A few days after his failed suicide attempt, the government caved in to the lobbying of Thomson and his allies and made funds available for a Resolution Island curator.
Henry Eventually made it to Dusky Sound in mid-1894, but government money didn’t stretch far enough to pay for an assistant, so he shelled out the wages for a helper, Andrew Burt, himself. Together, the two men built a comfortable hut on Pigeon Island, within rowing distance of Resolution. Their first six months operating from here were spent making preparations for the capture and release of kakapo and prospecting the mainland for the best kakapo-collecting grounds. The work invigorated Henry and proved to be the best medicine for body and mind in this “earthly paradise”.
Kakapo booming started in late November, and by January was like “distant thunder”. However, by the time a new sniffer dog arrived in February (the first having proved uninterested in the birds), the sound had become infrequent. Henry got straight into his work with the dog at the mouth of Wet Jacket Arm, beneath the slopes of Mt Forster—only a “short pull” to the shores of Resolution. With mapou, tutu and kotukutuku (tree fuchsia) in fruit, there was plenty of food in the form of purple-black berries for adult kakapo and their chicks.
Within an hour the new dog had found three nests, but it was apparent that the chicks were too small to be safely transferred, so Henry delayed this project until May, when the youngsters would be ready to look for their own real estate.
When Henry finally began transferring birds, three trips saw 75 kakapo carried to safety, but the fourth and fifth trips were thwarted by bad weather, which made it impossible to row across to Resolution Island. Henry had to come up with ways of holding and feeding birds in transit. Some could be placed in trees where they would feed themselves, and there were those that accepted hand feeding with oats and potatoes. It was a good start.
By November 1898, Henry had shifted 572 birds—kakapo and kiwi—and he thought the island stocked to capacity. His job now was to monitor and protect the birds and ensure that they were adapting to their new home. He also had to defend them from the incursions of both fishers and poachers, who threatened to undo much of his work by leaving behind dogs on Resolution Island. Furthermore, he had to educate tourists and excursionists, who merrily shot birds (mainly ducks) from the comfort of their craft. Henry was so concerned that he asked T.E. Donne, superintendent of the Department of Tourist Health Resorts, to “not publish a word about the birds” lest shooters be attracted.
But whatever human threats there were to Henry’s feathered charges could not compare with what was about to befall them. In March 1900, Henry Wright’s reservations as to the suitability of Resolution Island as a sanctuary were proved valid. Tourists aboard a passing schooner saw a “weasel” on the shore chasing a weka. At first incredulous, then mortified, Henry wrote: “This on Resolution Island! It looked so like a joke that I only laughed.” The magnitude of the situation soon sank in, and he immediately set out to trap the animal.
After seeing a set of weka chicks in the exact spot where the intruder had been reported, he wrote, “better evidence there could not be that there is no weasel staying there, for by all accounts a weasel has courage enough to attack a man and couldn’t be beaten off by a weka”. In the long lonely months that followed he kept up his dogged hunt until he almost came to believe that nothing had changed. But the uncertainty began to eat away at him. To quell his concerns he captured and transferred birds to some of the smaller surrounding islands, including Maori, Anchor, Prove and Nomans Islands. Eventually, six months after the “weasel” sighting, he saw a stoat on Resolution for himself.
Henry remained on Resolution until he was 63, not leaving until February 1908. For the most part they were not happy years. That pests had infiltrated his sanctuary gnawed at him and he spent much time trying unsuccessfully to track and trap them. Most of the time he was alone and visits from steamers were erratic and infrequent. His letters indicate he suffered considerable loneliness and depression. Part of the trouble was that there was little for him to do. Resolution held as many ground birds as it could support, and there was little more he could do to help them. He received few orders for birds, both alive and preserved in alcohol. Birds for live shipment often perished because of delays in the arrival of steamers, which upset him. Writing helped preserve his sanity. He wrote The Habits of the Flightless Birds of New Zealand, which was published and widely appreciated. As for the birds, for a year or two things seemed OK, but after 1902 the situation deteriorated. Robins and parakeets seemed to disappear from the Sound, kakapo became emaciated, then small birds such as New Zealand thrushes, creepers, korimako and tui disappeared. The birds of Dusky and Breaksea Sounds, including those on Resolution Island, were perishing and there was nowhere safe to take them.
Mustelids and rats were certainly part of the problem, but Henry noticed great increases in the numbers of introduced birds. Sparrows, thrushes and blackbirds were spreading everywhere, snatching food from under the beaks of natives. He wrote in 1907:
Kakapo, quite fresh and without a mark on it, but light as a bunch of feathers. I did not pay much attention to it then, but now… I think it may have been a specimen of starvation by imported birds, and I am greatly afraid it will be the fate of all kakapos…the new berry-eaters can fly and gather up to take the best of everything. He began to doubt that Resolution was good habitat for his favorite among birds, the kakapo, after all. Apart from rats, mustelids, wild cats and introduced birds, Henry had other problems. Hunting parties and fishermen and prospectors, all with dogs that killed birds at every chance, penetrated his remote domain and mocked him and his endeavours.
When he was offered the job of ranger on Kapiti Island in early 1908, Henry was glad to accept it. He left Dusky Sound in June of that year and took up the Kapiti post in July. In 1912 he retired from Kapiti and moved to Katikati, north of Tauranga, and finally, in 1929, shifted to Helensville. He continued to write the odd column for local papers but had few friends. He died in November 1929, age 84, from “senile decay and heart failure” in Avondale Mental Hospital.
Henery was rescued from obscurity by Don Merton of the Wildlife Service after he was charged with the job of saving kakapo from almost certain extinction in the 1970s.
“Henry’s writings,” says Merton, “more than any other, have been indispensable in our work… Henry was undoubtedly a remarkable and talented field naturalist. His extraordinarily accurate observations and records have given us insights into the biology of piopio [New Zealand thrush], kakapo and kiwi. We knew from Richard Henry’s experience that some of the birds were very stubborn and that they sometimes starved themselves. Henry recognised that even if they did not eat they would drink, so we gave them honey water, which they just loved. Then we would fortify the honey drink with [the dried-milk formula] Glaxo and a vitamin and mineral mix.”
Henry demonstrated that birds could be moved from place to place and that they could establish themselves successfully in new territories. “We got a fair idea from Henry what would work and what would not, and that became the platform for what we did with the Wildlife Service while moving critically endangered species.”
As for Henry’s theories on kakapo breeding: “We confirmed many of Henry’s theories on kakapo that were contentious even up until the 1980s. While radio-tagging females on Stewart Island and wearing night-vision goggles, we were able to confirm that the only years kakapo breed are those booming does not occur every year.
“Henry speculated that booming and breeding were related to the availability of food, though he was hard-pressed to justify his view for he found that the male’s air sacs started to develop several months before the seasonal abundance of food. Recent research indicates that booming and breeding are linked to the sporadic heavy cropping of certain food species.”
Merton also confirmed Henry’s belief that only females were involved in the incubation and care of young. This was disputed up until the 1980s, when Merton and his team confirmed that the male kakapo, as Henry contended, was just “a gay Lothario”.
Henry may ultimately have felt a failure as he watched his island of avian treasures being plundered by stoats, but his work was certainly not in vain. His true legacy is in his field notes and writings, which have been pivotal in establishing techniques for the rescue of several critically endangered species in New Zealand and around the world.
The Habits of Flight less Birds of New Zealand is an easy read, full of interesting and humorous anecdote while also packed with science. Ecology is a relatively modern field of research, yet, writing a century ago, Richard Henry expressed himself like an ecologist, weaving into his narrative the many environmental interactions he observed influencing the birds he cared for, rather than focusing solely on the purely ornithological detail so beloved of his peers. In many ways he was a man ahead of his time.
The COGS in my mind have always been slow to turn at 5 a.m. so I let Kerri-Anne Edge do the talking. Kerri-Anne has served her time helping with the eradication of rats and cats on subantarctic islands. Now she has her sights set on the elimination of stoats and deer from Secretary and Resolution Islands, in Fiordland.
“Until very recently, eradication of stoats was in the too-hard basket,” she tells me. “But the Campbell Island and Little Barrier Island rat eradications have convinced people to take the risks, and recently stoats were eradicated from three small islands down the Fiordland coast. I’m confident we’ll eradicate the Secretary and Resolution stoats.”
“But won’t they reinvade?” I ask. “We know they’ll reinvade.”
“Doesn’t that leave you in the same position as Richard Henry—stoats plundering your treasure trove?”
I’ve been planning to spend the next two weeks aboard Southern Winds, DOC’s coastal work-horse, with island-restoration staff from their Te Anau area office to get the long answer, but Kerri-Anne gives me the short answer now: “No. Henry assumed stoats would not invade: we are assuming they will.”
Soon we are ploughing through the south-west swell of the Tasman aboard Southern Winds, but once inside Thompson Sound, the swell disappears and with it goes our seafarers’ lethargy. Activity spreads across the rear deck as every one prepares to work. Hannah Edmonds demonstrates how to set traps, use the GPS and record data, while the gasping hydraulic arm of the davit lifts the zodiac out of its holster and drops it into the sound.
I board the zodiac with Clea Gardiner and Glen Clouston, volunteers from Northland, and Murray Willans, the Te Anau biodiversity programme manager, who is operating the craft. He times his run into the shore so that the boat hits the boulders just behind a swell, then he accelerates further to hold the hull against the rocks as the backwash tries to suck us out. Everybody leaps out, then he slams the outboard into reverse, hitting an oncoming wave perpendicularly, pivots the outboard and accelerates away. He executes this so accurately that not an egg (for baiting stoat traps) is broken.
We check, re-bait and reset all of the mainland traps along the 20 km length of Thompson Sound in a day. Trap lines are set parallel to the shore on the nearby mainland to try and intercept any stoats that might be tempted to swim across to Secretary Island.
Secretary is the second largest (8140 ha) and highest coastal island in Fiordland, rising steeply to 1196 m and it supports a wide range of plant communities and habitats ranging from lowland beech podocarp forest through to sub-alpine scrub and herb fields. Most of Secretary Island is more than 1200 m in a direct line from the mainland. This is significant because the maximal distance stoats swim is thought to be 1200 m. However, there are several stepping stone islands that are closer than this distance. Only good swimmers like stoats and deer have made it to Secretary Island and no possums or rats live on the island. Wildlife on Secretary has been hit hard by stoats. “The removal of stoats,” explains Edge, “will give protection to many species already on the island such as the Fiordland crested penguin, titi, northern tokoeka, the New Zealand falcon (karearea), kakariki and Fiordland skinks.”
The three small islands on which stoat-eradication programmes have already been carried out are Te Kakahu/Chalky Island (511 ha) and Pukenui/Anchor Island (1280 ha), in Dusky Sound, and Bauza Island (480 ha), in Doubtful Sound, the last-named being the largest of the “stepping stones” between the mainland and Secretary Island. Stoats on these islands would never have seen traps before so would probably have been cautious about entering them. To familiarise the animals with the traps, therefore, and reassure them they were safe, traps were laid and left empty for a while, then baited a couple of times but not set.
“The result was really surprising,” explains Kerri-Anne. “They got all the stoats almost immediately on Anchor and Chalky, and both islands have been stoat-free since. Bauza has proven a little more difficult. It is quite a lot closer to the mainland and we had a lower density of traps. It took us longer to get the stoats off but it has been stoat-free for two-and-a-half years. The really exciting thing is that bird life on Bauza has diversified and intensified significantly in that time.”
The same technique was used on Secretary, where, in July 2005, the first trapping netted 96 stoats. A return trip in November caught just nine.
No one really knows what to expect on this trip. Female stoats tend to be very cautious after giving birth, which could account for the low take in November. If that is the explanation, we can expect to catch a lot of young stoats on this occasion. If the November trapping was a true indication that numbers on the island were low, we are likely to catch few stoats. So tonight on Southern Winds we wait with anticipation to see what the island trappers have found.
Edge starts the 8 p.m. sched. “This is Southern Winds, Southern Winds. Do you copy, Simon?”
“Go ahead Southern Winds.” Skeletal radio chat, pared back to the essentials.
“How are ya?”
“How did ya go?”
“I got six stoats.”
Edge moves on to see how Scott Theobald has fared. Scott is a dog handler who trains his dogs to track and indicate stoats. He’s trapped three, and his dog, Tui, has found him another. It appears we’re catching the inexperienced juveniles and that the wily females did indeed avoid capture in November.
The next morning, a Zodiac flings me ashore with Eigill Wahlberg, from DOC Twizel, and together we walk one of the trap lines. We’re soon climbing through thick bush. Secretary Lake is almost one vertical kilometre above us.
Secretary Island may be home to only two kinds of mammalian pest, but deer and stoats have knocked the island’s ecology totally out of kilter. Over dinner last night, Murray told us, “The bush is noticeably quieter than on the mainland.” Stoats on immediately rodent-free islands do not have a ready supply of small mammals, so they target birds. Even the more resilient species, such as fantails and bellbirds, find it difficult to survive, while cavity-nesting birds, such as kakariki, mohua (yellowheads) and kaka, find it nigh on impossible.
Half an hour along the trap line, I’ve seen a handful of fantails, a rifleman and a couple of bellbirds. By the time we reach Secretary Lake I’ve counted dozens of juvenile fantails and bellbirds, two riflemen, numerous tomtits, four kaka and four kereru. I’ve also heard regular weka calls. Eigill and I are sure we’re witnesses to a resurgence in bird numbers.
Another thing I notice is the health of the vegetation. Secretary Island has never had to bear the grazing of possums and rodents, so plant diversity and vigour are impressive. Mistletoe, mountain lancewood, gentians, olearias and Easter orchid are just a few of the species that grow in abundance.
Next day I climb a steep track in the company of Hannah Edmonds and her stoat dog, Zephyr.
“One of the valuable things about Secretary is its sheer scale,” she tells me. “There are heaps of different habitats here, so lots of different species can make use of it. We’ve never seen any rock wrens, but Secretary has an alpine environment so we may be able to put some here. Like everything they’re going downhill on the mainland.”
I recall that in 1851 a takahe was caught on Secretary, opposite Deas Cove in Thompson Sound, so I ask about reintroducing the giant rail.
“It isn’t out of the question that takahe may make it back to Secretary, but there’s probably not enough suitable habitat to support a self-sustaining population. They have quite big home ranges, and the food here doesn’t appear as good as up in the Murchisons.”
During lunch we’re given a graphic demonstration of how vulnerable ground birds are to four-legged hunters. Zephyr is eyeing a sandwich when two weka silently walk up behind us. Zephyr has been trained to find stoats and leave birds alone, but her gaze immediately shifts from sandwich to weka. You can tell it isn’t easy for her to just watch the birds. The weka walk to within a metre or two of us. Every sinew in Zephyr’s body is tensed, watching the birds. Her training has taught her not to break the point. Any untrained dog would have pounced on them.
By the fourth day the weather looks as if it might close in. Conditions are pretty bleak while I wait to be picked up from Bauza Island, where just one stoat has been caught. Bauza is 600 m from the mainland at its closest point, overlooking Patea Passage, and 150 m from Secretary where Te Awaatu Channel is narrowest. Kerri-Anne concedes that the stepping-stone islands effectively bring stoats closer to Secretary, but doesn’t see that as all bad. “Steppingstone islands are extremely useful in terms of protecting your jewel. We know stoats have to go through them to get to the main island, so you can load them up with traps.”
In four days, we’ve taken a total of 48 stoats off Secretary and Bauza Islands.
“It would have been nice to come out to Secretary and not catch any stoats, but we were expecting they would be here,” comments KerriAnne, who refuses to be drawn on when she thinks Secretary will be stoat-free. “We’ll review the programme in May 2007 if we’re continuing to catch stoats and the numbers aren’t decreasing.”
You often see up to 80 mohua flocking. There were probably 40 back there in the bay,” says Murray when he collects us from the eastern shore of Breaksea Island. “The beech forest would have been a noisy place before stoats.” He speaks with enthusiasm, not regret—probably because he’s seen how much a few committed people can achieve. “Islands certainly stack up when you compare them with what we’re spending on the mainland. The conservation gains you get on these islands are much, much higher and more defendable than on the mainland.”
Murray concedes that inshore islands are not as secure as offshore islands, but goes on: “Controlling rats over 800 ha in the Eglinton Valley is going to cost us $150,000. Resolution and Secretary total almost 30,000 ha and we aren’t going to have to spend a cent controlling rats. After the stoats have been removed the reinvasion rate will be low, as water around these islands is a natural barrier, so there’s a buffer against the continuous immigration of stoats.”
However, as Richard Henry learned, water is not an insurmountable obstacle to stoats. Last year a stoat was caught on Centre Island, in the middle of Lake Te Anau, over 2 km from the nearest other land—an exceptional distance for the animal to have swum.
“Richard Henry failed because he worked on the assumption that stoats would never get to Resolution Island; but they did. We know they can swim huge distances, but what is really important is how often they do this and whether you can catch them before they do any damage to the special things that you have on the island. I think our ability to catch stoats is probably better than we suspect.”
Murray draws this conclusion from trapping statistics gathered around mainland Fiordland and on the 30 inshore islands being monitored to measure stoat reinvasion. A lot of sophisticated maths has been done on the findings, but Murray gives me a simple rule of thumb:
“If an island is closer than 300–400 m from the mainland, you’re going to get stoats quite regularly. Islands like that are probably not a lot more valuable than the mainland. Beyond 400 m, islands become much more valuable. And for most of the islands that we think are valuable, we provide another level of protection on top of the natural water barrier. We put trap lines on the adjacent mainland.”
Recently, Anchor Island has become a refuge for kakapo and other endangered birds, including the South Island saddleback (tieke) and the South Island robin (toutouwai). Stoats were eradicated from the island in 2001, and the last deer have been removed since then. Kakapo and other birds depend on the shrub under-storey for fruit and foliage, but deer can badly damage this. Walking through the mixed podocarp forest it is obvious recovery is taking place in this lower layer, with young totara sprouting up everywhere.
The next stop on our island odyssey is Chalky Inlet. Out in the Tasman there is a solid south west swell, and a westerly wind flicks manes of sea spray off the backs of the breaking waves and fuels the flight of seabirds, which range from fluttering shearwaters to wheeling Buller’s albatrosses. Soon the white-layered limestone cliffs of Chalky Island come into view.
In the late 1980s, the kakapo-recovery programme was in desperate need of safe havens. Dave Crouchley, head of takahe recovery, proposed Chalky—once it had been cleared of stoats, which he suggested was possible. Richard Henry, he noted, had visited both Chalky Island and neighbouring South Passage Island in 1906 and considered them ideal for kakapo.
The Passage Islands lie between Chalky Island and Great Island, the latter being very close to the mainland—well within stoat swimming distance. North Passage Island, an islet very close to its larger southern namesake, is 1200 m from Great Island—right on the maximum distance stoats are likely to swim. Neither Chalky nor South Passage has supported a resident population of deer, possums or rodents, so the flora is pristine.
This combination of factors encouraged DOC, in 1999, to try its first stoat-eradication programme on Chalky. Its success led on to the eradication of stoats on Anchor and Bauza Islands and gave DOC the confidence to proceed with the ambitious plans to eradicate stoats from Secretary and Resolution Islands.
Our trip to Chalky coincides with a release of the critically endangered orange-fronted kakariki. Since 1999, when it was realised that the orange fronted kakariki was distinct from its red- and yellow-fronted relatives, its numbers have plummeted. Only 100–200 of the birds remain in three Canterbury valleys, two in Arthur’s Pass National Park, the other in Lake Sumner Forest Park. As a result, this rare parakeet has had the dubious honour of joining kakapo and takahe on the list of New Zealand’s most endangered species.
I join Kerry Weston, who yesterday supervised the release of 15 birds, and she explains why it was important to get them to a predator-free island.
“They roost and nest in tree cavities, which makes them vulnerable to predation by rats and stoats, so they will never be entirely safe on the mainland. Therefore the top priority is to establish a population on Chalky Island.” Kakariki feed on a range of invertebrates and plant material, including seeds, buds, shoots, flowers, leaves, ferns and grasses
“With no introduced predators and plenty of food on Chalky, if they can handle the stress of being moved here they should do well.”
A tiny transmitter has been attached to the tail feathers of each bird so researchers can find them and observe how they’re coping during the first weeks after release. One has died overnight, and I accompany Kerry while she checks the rest. Without transmitters it would be impossible to find them. They’re superbly camouflaged, and the scrub is so dense that on one occasion we return to a hebe bush three times before we see the bird our receiver tells us is there.
After we’ve located all the birds and observed them for a short while, Kerry takes me for a quick tour of the island. A pair of falcons circles above us before one of them barrels into a dive and crashes onto an unsuspecting bird in the canopy. Is it one of the kakariki, we wonder? With the dead bird in its talons, the falcon drops to the track, where it’s joined by an excited mate. By the time we arrive on the scene, all that remains of the attack is a few shiny blue-black tui feathers. This time the kakariki have been spared.
One of the most important things about Secretary and Resolution Islands is that they’re big enough to hold large self-sustaining populations of birds. Once they’ve been rehabilitated and stocked, therefore, the loss of one or two individual birds won’t jeopardise the survival of a whole species. Although not impregnable to mammalian intruders, they offer the best hope for many critically endangered and declining mainland species.
Secretary is on track to become New Zealand’s first large stoat-free inshore island, while track work is due to begin on Resolution in September 2007. According to current simulations of kakapo biology and productivity, female kakapo numbers could swell to 150 within the next two to four decades if these two islands are used as sanctuaries. It may have taken over a hundred years to make any inshore island safe, but it is still not too late. The dreams of Thomas Potts and Richard Henry, of having large, safe havens for kakapo, kiwi and other vulnerable native birds, may yet be realised.