Campbell’s lost parrot and other cautionary tales
Campbell Island’s snipe flew home from its precarious refuge on tiny neighbouring Jacquemart Island recently and onto prime-time television news. Less than four years after the extermination of 200,000 brown rats on Campbell Island in the largest operation of its kind anywhere in the world, the snipe’s return was an astonishing and important event. It was certainly worthy of a better news slot than that between the weather and the wrap: as a landmark event in New Zealand conservation it surely merited as much screen time as the latest sports injury. The bold kilometer-long flight across sub-antarctic waters showed that, given the chance, our wildlife can make it. Unknown until 1997, the snipe had for 160 years survived amid gale-blasted vegetation clinging to 19 steep ha above vertical cliffs. The little bird’s success is just the latest leg of a far longer journey to reverse long-term environmental damage on the island, and is a fine reward for the daring and professional team that, in midwinter 2001, cleared the 11,300 ha island of rats.
Campbell Island is part of New Zealand’s subantarctic World Heritage Area—remote, beautiful, frequently forbidding. The southern islands have resisted all attempts at permanent settlement. Seals and whales proved incapable of surviving industrial-scale predation, while the harsh climate and distance from markets killed off farming ventures. Now the islands are reserves, a source of revenue for tourist companies and of wonder for their clients. Forty years ago, conservationist Gerald Durrell listened in disbelief to a cabinet minister dismissing the islands: it didn’t matter if royal albatrosses became extinct because no one could go and see them anyway. Somehow, damaged but not destroyed, these magnificent birds have weathered exploitation and active political indifference. Fortunately, people—or at least those with enough disposable income—can go there now and bring back images and sounds to share with the world. But what is the real state of the islands, and what will be the effects of our present management? Answers may lie in the mists of history.
Subantarctic island histories tell of treasure and tragedy, of hardship and perseverance, shot through with a touch of opportunistic scientific endeavour. The islands’ bleak shores received expeditions from Europe during the era of scientific colonialism, and since the 1840s, English, French, Americans and Russians have all added to the pool of knowledge. Darwin’s great friend and confidant, Joseph Dalton Hooker, drew on first-hand experience and his own collections to describe the botany of the southern islands. But Hooker and the others were already studying damaged goods. Drastic changes had begun with the first visitors, the sealers.
Sealers were secretive people. Their business was finding and exploiting isolated seal-rich islands, reaping the bounty for as long as it lasted. Island locations were usually closely guarded commercial secrets. Hence, the visit to Campbell Island recorded in the log of the sealing brig Perseverance in 1810 may not have been the first by Europeans. Yet southern sealing did not begin until the 1790s, so any earlier visits could not have been many years before that of Perseverance, and Campbell Island’s plants and animals in 1810 are likely to have been in as close to an original state as any seen by Europeans in New Zealand. The date is therefore a convenient one on which to hang the island’s recent history.
Unfortunately for the natural inhabitants of Campbell Island, sealing gangs—bad news that they were for the fur seals they harvested, and the penguins and albatrosses they lived on—were not the only new arrivals. By the 1790s, brown rats—also called Norway rats despite originally coming from southern Asia—infested ports and vessels, and sealing and whaling ships delivered them free to islands around the world. Also known as water rats, browns are not afraid of getting wet—in fresh or salt water—and proved able island colonists, soon at home even on bleak specks of land such as Campbell and the glacier-bound South Georgia. We don’t know who took brown rats to Campbell Island, but we can work out roughly when they arrived.
The first scientists to visit the island recorded what they saw, but they could not know what was missing, and most of what was missing had gone down the throats of rats. By late 1840, a bare 30 years after Perseverance’s visit, James Clark Ross’s expedition to find the South Magnetic Pole recorded no land birds at all.
Later researchers found a teal and a song-bird (and, in 1997, the snipe), but grumpy surgeon-naturalist Robert McCormick did not see these in 1840 because they had already been banished to rugged stacks too small to warrant visits by the scientists aboard Her Majesty’s ships Erebus and Terror, and in many instances, still impossible to land on today. These last tiny refuges from the rats included tooth-like Dent Island, off the north-western coast (conferred by French explorers, the name rhymes with “want”).
Dent and two other islets were refuge, too, for the local pipit, but the snipe was confined to Jacque-mart, off the southern coast. Missed in its castle keep by the first human visitors there in 1984, it was seen and photographed in 1997 by people looking for more teal. Its relationships are still unknown because no feathers have been collected for DNA analysis, but even so it fills a puzzling biogeographic gap. It may have been unknown until 1997, but its presence was not unexpected. Other southern islands have their snipe; the puzzle was why Campbell Island did not have one. And there are similar gaps in other widespread groups. Even Macquarie Island, further south and more remote yet, had its rail and duck, both of which made it into the 19th century but not beyond, and all the islands have parakeets. The question was, was Campbell special? Had rails or parakeets or other songbirds never reached the island, or had they got there and died out? And what about the petrels? Had diving petrels, prions and storm petrels always been confined to the stacks?
With no possibility of finding more land birds lurking on offshore islets, there was only one way to go: down. Limestone outcrops and dune systems offered the hope that there might be fossils. We could dig for answers.
Funding is always tight for research and management in the subantarctic, and even tighter when it is based on a hunch; so hunch had to be married to opportunity. That came in September 2004 with the triumphant repatriation of the teal, first fruit of the rat–eradication campaign. From then, the hunt was on. Space was found for Jeanette Winn, veteran of over a decade of palaeontological research. Time was short, and Jeanette had searched several possible sites without success before a test pit under an overhang above Perseverance Harbour yielded six identifiable bird bones. Then she had to hurry to catch the boat.
You have to be lucky sometimes. One of the bones came from a parakeet—Campbell’s lost parrot, at last. Whether this bird was unique to the island cannot be stated before the results of DNA analysis are available, but at least we now know that Campbell Island did have a parakeet. The other five bones? Three were identified as Richdale’s diving petrel and two, both juvenile, as sooty shearwater, confirming both these species once bred on the main island. But there is the shadow of another bird too, evident not in the bone count but in the result of its actions. One of the shearwater bones features a notch made by a predator’s beak, telling us that falcons—some of the southernmost in the world—once graced Campbell Island skies. The island appeared different from other subantarctic outposts only because rats had arrived early enough, and done their job fast enough, to erase all above-ground evidence of birdlife before McCormick stepped ashore. They managed it within about 30 years, meaning McCormick was a few years too late to eat snipe and watch parakeets rocketing above the tussocks and megaherbs.
What can we learn from the parable of Campbell’s parrot? First, as Horatio found, there are more things out there than we might think. Life has patterns, but we may need to dig below the surface (literally) to find some of the pieces. Fossil evidence can flesh out what we know of these remote islands. The story of the parrot and its companions on Campbell Island, and the efforts to sustain them and their home, echo the experience of all New Zealand over the past 2000 years. Fossils are the only means we have of knowing what the main islands were like, too. The cultural landscape that is New Zealand today can tell us only so much about the environment in which such iconic species as takahe and kakapo evolved. To save and manage them and all the rest, we need to know far more about what used to be here and how it all worked.
The lost petrels of Campbell Island are telling us something, too. They are saying that nutrient cycles and succession cycles of vegetation there are not what they used to be. No account of the vegetation and animal life of Campbell Island can ignore the fact that millions of birds once occupied millions of burrows there, fertilising the land with thousands of tones of nutrients brought in from the Souhern Ocean and, in effect, ploughing the fertiliser in deep.
We know that at least 14 species of petrel nested on the South Island, but have scant idea of how they fitted into the terrestrial ecosystems, or even if they determined what those systems were.
The parrot was discovered because a Department of Conservation manager was prepared to take a punt and let palaeobiology have a go. He found a berth on a tight ship, and we found a person who could help with the teal transfer but who was also skilled in unearthing bone deposits. Now, anything older than last year’s budget is usually off the map for managers and funding agencies. The concept that the past is important, and that a few bones can take you where binoculars and modern ecology cannot, has at best gone unappreciated.
Popular fallacy has it that palaeobiology—in our case, studying recently extinct birds—is about mounting expeditions to exciting places to haul another moa skeleton or two back to glass cases and storage basements. Glitz and one-day glamour, maybe, but not really science. Collecting as an end in itself is 19th century science. Then, the job was over when the bones had been identified, labeled and listed. Now, collecting should be done only as the basis for dealing with larger questions. The richest results come from work after catalogue entries have been made. New high-tech tools for interpreting the structure and function of past environments are begging to be applied to the riches of New Zealand’s recent fossil record. They promise us a perspective of the past that can guide and underpin our responses to the challenges of the present and the future. It is time to recognise the extraordinary value of recent fossil deposits, largely ignored here by science both in teaching and in practice. Society’s indifference means that, unlike our thin human heritage, the natural resource of the palaeontological record is completely unprotected by statute. It should be cherished and conserved as a vital part of our national heritage and identity, and mined for information fundamental to conservation.
Progress in understanding our recent past and what it can teach us about the present demands properly trained professional researchers, encouraged by peer and public recognition that they are playing a role in New Zealand’s future and not just fixating on a lost past.
Progress will not be helped by high fees for bona fide researchers wishing to sample museum collections for the ancient DNA and stable isotopes that can reveal so much about our astounding past. Given museum managements’ grudging support for collections, even at Te Papa, it is ironic that for some institutions collections have become a means of offsetting costs rather than the substantial basis of a thriving and relevant—science. The Campbell parakeet is just a small example of how our horizons can be opened up by allowing the orphan palaeobiology a seat at the table. Its bone, collected on a hunch, has been halved: one half will be preserved as a permanent record; the other has been sacrificed to ancient-DNA analysis so that an ex-pat Kiwi can fit into place what is a new piece of the jigsaw of New Zealand’s life. We must fill in more of that jigsaw if we are to take more than museum relics of our rich heritage into the future.
Conservation management in New Zealand has come a long way, with many successes to balance the trials, blind alleys and inevitable abject failures. The Campbell Island experience is its microcosm. Take the teal; when it was rediscovered rat eradication was only a dream, so there was no alternative but to bring the birds north and breed them in captivity. Returning them to their own island is an unexpected bonus, flowing from the new technologies of predator removal. For 40 years, translocation has been used to save rare species in New Zealand. The technique came too late to save those species lost when Stephens Island was trashed in 1894, and it failed the South Island snipe and the bush wren when, in the early 1960s, it could be practised only in defiance of official instructions. But, clandestine or otherwise, the first successful moves ensured the saddleback could be brought into the 21st century; and when translocation was finally, if grudgingly, accepted, it allowed the black robin to stage its astonishing comeback in the 1970s and 1980s.
Now that predator removal has become more of a science than an art, species can go home or stay at home. Some, like the snipe, can even go home under their own steam. Spending money on deratification saves far more in the long term. Spending some on research into past systems would not only show us that the Campbell Island landscape needs the flash of green and blue parakeet wings to be truly restored; it could also provide a context and a structure to guide sustainable conservation on islands and on the mainland, now and in the future. And conservation has to be a commitment in perpetuity if the efforts of today are to have any meaning at all.