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Ocean Notorious

Page 4

by Matt Vance


  Campbell Island is one of those places few people can point to on a map, but despite its obscurity it’s notable for many things. Perhaps the most conspicuous are the incessant westerly wind and the lack of trees. Technically speaking, the Sitka spruce, or Picea sitchensis, is the only tree on the island.

  Even though its nearest taxonomic cousins live far away in the northern hemisphere, the spruce is thriving in its own peculiar way. All the surrounding vegetation consists of wind-tolerant, low-lying shrubs and grasses. Most huddle in a dwarf Dracophyllum forest as thick as a woollen jersey. There are two species of this Dracophyllum: D. longifolium and D. scoparium. They are so similar in appearance and have so many intermediate forms that even hardened botanists have trouble telling them apart. On mainland New Zealand longifolium can grow up to five metres tall, but in the blustery climate of Campbell Island the plant can barely muster a stunted couple of metres, making it technically a shrub.

  Dracophyllum has evolved a perfect defence mechanism. The flow of wind across its canopy produces eddies that pass down through the stems and trunks, causing the surrounding plants to brush into each other. On windy days this rhythm of eddies can be seen as a series of pulses that ripple like a wheat field swaying in a summer breeze. The closer the plants huddle together the less chance there is of damage: any large gaps in the canopy would allow the wind to penetrate, causing mayhem. Dracophyllum has perfected the sense of community; you have only to duck your head down a few feet below the canopy to be in the blessed calm of its thick stringy interior.

  In 1901 Lord Ranfurly, an eccentric governor of New Zealand, visited Campbell Island on a steamer, the Hinemoa, while touring the outlying reaches of the dominion and collecting bird specimens for the British Museum. As with many governors and ministers of the Crown before and since, the baubles of office were shamelessly pursued. On board Hinemoa were Lord Ranfurly’s family, his servants and sixty tons of personal luggage.

  By his own admission the governor’s bird-bagging was not a complete success. Wind sometimes buffeted his shotgun, letting many a rare species flap away unharmed into the Dracophyllum. Despite this, the governor was impressed with what he saw of the island and lamented the fact it was not in productive use and contributing to the expansion of the British Empire.

  While records of the cruise are slim, it seems Hinemoa’s visit coincided with a rare spell of calm weather in the Southern Ocean. A windless day on Campbell Island has a special charm, and it was probably this that fuelled Ranfurly’s notion that the island could be cloaked in forest. In the great New Zealand tradition of celebration, it was decided a tree should be planted. On Hinemoa’s next scheduled visit a site was selected at the head of Camp Cove and a Sitka spruce sapling set in the ground. In time, this hardy newcomer became known as the Ranfurly tree, a symbol of progress and development that miraculously endured despite constant squalls and the aching desire of later inhabitants for a Christmas tree. Over time, the Ranfurly tree showed the kind of grit that can get a tree noticed.

  Lord Ranfurly , c. 1900.

  The Campbell Island Sitka looks deceptively calm but this is a façade, masking the tortured life within. Sitka spruces are big trees that live a long time. In doing so, they have to fight the constant onslaught of gravity, wind and mad bastards with chainsaws. They are genetically programmed to drive skywards in a race for light in competition with others of their species. This means they face major mechanical stress that would never happen to, say, plankton or jellyfish.

  How and why trees attain their myriad forms has been the focus of much dry thinking by scientists. In the 1970s a French botanist, Francis Hallé, came up with an architectural system for classifying trees. He defined twenty-three different models and threw caution to the wind by naming each after another prominent tree botanist. He came to the conclusion that a tree’s architectural form is merely its genetically programmed plan of growth. He posited a picturesque world in which every tree looks the same as its kin.

  To continue to believe in this state of perfection, Hallé would have had to avoid visiting Campbell Island. In reality a tree’s growth plan is only part of the picture: its eventual form will also reflect its environment, accidents, and the stresses of life in the breeze. Lightning, a storm, a chainsaw or a truck can cause permanent modification to a tree’s form. As professors of forestry Martin Zimmermann and Claud Brown point out in their book Trees: Structure and function: ‘The shape of a tree represents an interaction between destiny and experience.’ Destiny decreed that the Campbell Island Sitka spruce would be 100 feet tall with a structure based on a towering central trunk. Instead it is a stunted tree with multiple trunks, not unlike the shape of a cabbage.

  The only other Sitka spruce with which I was acquainted sprung from my childhood, and it too was a solitary survivor of the west wind. The great nor’westerly storm of 1975 whistled out of the Southern Ocean and slammed New Zealand’s Canterbury Plains, where my family lived. After a night fearing we’d lose the roof of our house, we were presented next morning with a strangely silent sight: every pine and macrocarpa tree around our isolated little home was lying on the ground. Only one tree was still standing. I asked my father what it was. ‘A Sitka spruce,’ he replied. Despite the tree’s unusual colour and staunch form, which seemed to hug the ground a little more than that of the other trees, I had never noticed it before – the sappy pines and twisted macrocarpas had been better sites for tree huts.

  I grew to love that old tree. As the landscape restored itself to open paddocks and shelter belts I would return to climb it time and again, sometimes with mates, sometimes alone. From a neat cradle of branches near the top you could see across the plains to the edge of forever and the promise of adventure beyond our small country town. High up there it seemed to a daydreaming boy that nothing would change. The paddocks would always stretch to the distant Southern Alps, the rivers too vast and the space too big ever to be filled.

  I didn’t know how the tree had remained upright while every tree around it had toppled until as an adult I came across an article in Natural History magazine by Steven Vogel, a biologist. In ‘When Leaves Save the Tree’, Vogel pointed out that while most of the weight of a tree resides in its trunk and branches, the majority of its surface area is in its leaves. The leaves are not only vital for capturing energy from the sun, conserving water and aiding cooling, they are responsible for a huge amount of drag, which can topple the tree in an extreme wind.

  Vogel had wondered if some trees had developed techniques for reducing drag. He set about placing small branches of various species in a wind tunnel at Duke University and observing their response to increasing amounts of turbulent wind. To his surprise he found that as the wind increased many leaf structures morphed into streamlined shapes. In the case of the tulip poplar, Liriodendron tulipifera, the leaves folded, then curled up lengthwise until they formed slender stable cylinders. In holly trees the leaves flattened against each other, making a thin stack, while the white oak kept its leaves horizontal and clumped them into a stable mass.

  Vogel found that the needle-shaped leaves of the mainland Sitka spruce formed into low-drag arrows during extreme winds. However, it was what lay beneath the ground that gave the tree its toughness. Further studies by tree-struck academics suggested that the Sitka’s stability is in part due to its ability to grow asymmetric root structures, with as much as sixty percent more growth on the windward side in environments like the Canterbury Plains and Campbell Island, where strong winds come from a consistent direction.

  On a recent expedition to Campbell Island, forest ecologist Jonathan Palmer managed to extract a core sample from the Sitka spruce with a view to studying potential climate variation. To his surprise he found the thickest branches of the 100-year-old tree were only forty-six years old: the main trunk had been altered not by the ravages of climate change but by vigorous pruning of the chainsaw kind. From 1941 to 1995 Campbell Island had hosted a meteorological station. For the small complement of
meteorologists and support staff the feeling of isolation would have been keenly felt, especially at Christmas. The desire for a Christmas tree may have led them to commit an unspeakable crime.

  The thought of the tree having been attacked stirred my memory. When I got back to New Zealand I took a sentimental journey to the town on the plains where I grew up, hoping my own Sitka spruce was still extant. Returning to a childhood haunt can leave you with a feeling of devastation and this was no exception. Under the guise of progress, developers had surrounded our old home with subdivisions full of giant houses and carved up the land with cul-de-sacs. Gone were the paddocks, shelter belts and endless unsullied vistas to the Southern Alps. Gone, too, was the Sitka spruce, felled to make way for a garage and a rotary washing line.

  Material progress seems an inevitable sin of civilisation but sometimes it’s the little things that stop it in its tracks. On Campbell Island, Lord Ranfurly’s vision of orderly development was never realised. Although several attempts were made at introducing forestry, the plans were always stymied by the incessant wind, the waterlogged soil and the plain isolation of the place. In time all thoughts of commercial ‘improvement’ of the subantarctic islands were abandoned. The British Empire crumbled and in 1904 Lord Ranfurly left New Zealand to pursue the baubles of office elsewhere.

  On Campbell Island the wind still whistles in the branches of the lonely tree as it stands, solitary and crooked, comforted by the whispering of the Dracophyllum.

  Merganser, painting by George Lodge, c. 1913.

  Extinctions great and small

  52°35′S

  Human colonisation of remote lands has often led to extinctions of the local fauna. Mainland New Zealand is a painful example: multiple waves of settlers have wrought havoc on bird species that had evolved no form of defence against humans and their entourage of pests and domesticated animals. The Auckland Islands, though, are a happy exception having lost only one species of bird to human-induced extinction.

  Of course extinctions are not always small and quiet, nor do they always happen in small out-of-the-way places. Sometimes they are loud and global. For most of Earth’s history mass extinctions have swept the planet like a sort of evolutionary spring-cleaning. For homo sapiens, these clean-outs have been a double-edged sword: they have eradicated competition and allowed us to evolve as a species, but at the same time the reduction of species diversity has been a surefire way of exposing us to extinction ourselves.

  It’s believed the last great mass extinction happened sixty-five million years ago. Something, perhaps an asteroid, hit the planet with the force of 100 million megatons and wiped out seventy percent of life, including the vast species of dinosaurs and ammonites. The odd thing is that some species came through this armageddon unscathed. Delicate little creatures such as salamanders survived.

  While destruction was global, isolation had curious consequences for the place known today as New Zealand. These islands became an extraordinary repository of unusual plants and birds – and thanks to their remoteness they remained that way for a long time. Humans were slow to arrive. The first who got there, voyaging south by canoe through the Pacific in an island-hopping diaspora, launched the process of species extinction. Later, colonists from Europe brought such wonders as shotguns and stoats, and with them the ability to wipe out multiple species on an impressive scale.

  On the Auckland Islands a little fish-eating duck called a merganser kept out of the way and survived the first wave of European contact. There are six known species of this duck and most occupy high-latitude lakes and streams in the northern hemisphere. The first recorded sighting in the Auckland Islands was by members of an 1840 expedition led by Jules Dumont d’Urville, the French equivalent of England’s Captain James Cook. During February the expedition stopped in at Port Ross on its return journey from Antarctica where its members had been looking for the south magnetic pole. A merganser was shot, skinned and added to the boat’s huge haul of animals and plants never before recorded by science.

  The classic island biogeography I learnt at university held that when animals arrive on isolated islands that are free from predators and abundant in food, they slowly evolve to become bigger and hairier than their continental cousins. Unfortunately this did not apply to the Auckland Islands merganser. Sketches by Louis Le Breton, the artist on board d’Urville’s ship the Astrolabe, show a skinny bird with a body like a cormorant and the plumage of a grebe. The creature’s most notable feature is its beak, which is serrated into what look like teeth. The male has a burst of colour around its head and neck.

  Competition from the more plentiful and socially resourceful shags seems to have confined the mergansers to the shallow coastal bays and streams of Carnley Harbour and protected eastern bays of the main island. This marginal habitat limited the population to fewer than a hundred for most of the birds’ existence. Over many generations the merganser shrank, its wings grew short and stubby, and it only just retained the ability to fly.

  Only one brood of ducklings was ever reported; two of these ducklings now reside in pickling jars in New Zealand’s Otago Museum. There is one report of the birds in a stream, one report of them flying and eight other first-hand accounts of sightings in the wild. The birds have not been seen since 1902 despite extensive searching. All that remains of them, apart from the pickled ducklings, are twenty-five skins, six in New Zealand museums and the rest in the UK.

  Biologist and waterfowl expert Murray Williams has done most of the detective work around these vanished creatures. With a little help from stable isotope analysis, he has discovered their preferred environment was a combination of both fresh and brackish water: the mergansers managed to hang out in creeks and hide in the tussocky edges of the quiet bays. It is testimony to the power of evolution that they kept living and adapting despite the intense competition for food and having no chance of breeding with other populations of mergansers. Until Dumont d’Urville spotted them they were doing all right.

  The ornithologist Walter Lawry Buller proclaimed what turned out to be the humble duck’s death sentence when he said in 1891: ‘It is desirable that specimens of this interesting form be obtained for our museums before it is too late.’ In the next decade collectors of rare birds shot at least twenty.

  At the front of the lynch mob was none other than the New Zealand governor, Lord Ranfurly. When the natural history curators at the British Museum heard that Ranfurly intended to make an annual cruise to the islands, they requested he obtain as many specimens as he could for their collection. The governor was delighted: this would be a great boost to his reputation as a bird collector. He ordered many jars of various sizes to be made, then had them filled with formalin solution and loaded aboard the government service steamer Hinemoa. He invited museum curator Frederick Wollaston Hutton to come along as his guest. Hutton’s knowledge of natural history meant he and his men could do the work while Ranfurly claimed the glory.

  At each island a thorough search was made to procure examples of local bird species. After being downed by shotgun the birds were quickly sketched to show important aspects of their colour and plumage before being treated with formalin to preserve their skins. The bodies were then packed into the jars and forwarded to the British Museum.

  Obtaining specimens of the Auckland Islands merganser proved difficult. A visit to the known hideouts of Carnley Harbour and Port Ross produced nothing. William Ogilvie-Grant, a Scottish ornithologist on board, recorded: ‘To show how scarce [the merganser] are, a gentleman went around the crew of the government steamer, prior to its sailing from the Bluff, and offered £3 10s to any of the men who would procure a skin for him. As this offer was made with a view to reselling, probably at a large profit, the rareness of this duck may be easily understood.’

  Ranfurly redoubled his efforts, ordering Hinemoa to enter every bay and inlet in the islands. His persistence paid off. He recorded in his journal: ‘Our great prize was the Merganser australis, a kind of duck very rare …
we have so far shot 4 of them.’ A year later, on another cruise to the islands, he noted: ‘Shallock shot 2 mergansers (a rare duck) in the harbour.’

  Few records exist of exactly where these specimens ended up. In 1994 one was found in Dublin Museum with a collection date of 1902 and Ranfurly’s name attached as collector. Murray Williams writes: ‘It is hard to escape the conclusion that this species was collected to extinction and that the final act of extinction was by vice-regal command.’ Today the closest you will get to a Merganser australis is a stuffed specimen in the attic of the Otago Museum.

  In recent times there have been quiet attempts to save rare and endangered species of birds before it’s too late. One of these took place 143 nautical miles south-east of the Auckland Islands, on a rocky outcrop called Dent. The island, which looks remarkably like a tooth, is the last refuge of the Campbell Island teal, a small brown flightless duck.

  For reasons associated with the place’s extreme remoteness and formidable coastline – your chances of getting ashore without drowning are slim – Dent has remained free of rats and the other afflictions of civilisation. It was not until 1975, when three men from the New Zealand Wildlife Service were able to scramble on to the island in a spot of calm weather, that its true value became apparent. The youngest member of the trio, Rodney Russ, thought he saw something that looked like a teal. At first his colleagues put this down to the exuberance of youth, but as they wandered around a small brown bird did indeed dart in front of them and Russ secured it with a diving tackle into the tussock. The teal was the pioneer in what would become a twenty-year breeding programme to save and eventually release the species back on to its native Campbell Island.

  As simple as this sounds it was a mammoth undertaking because the island had to be first cleared of rats. Twenty-six days, 120 tonnes of bait and some skilled helicopter flying in rugged winter conditions proved successful. While the teal was not the first New Zealand species to be saved, nor Campbell the first island to be cleared of rats, the project remains a high point in a world where extinctions occur by the day and special places are turned into subdivisions for humans.

 

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