Survivors: The Animals and Plants that Time has Left Behind. Richard Fortey

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СКАЧАТЬ more appropriate, since splendid alpine New Zealand has been repeatedly used as the location for the movie version of Tolkien’s saga. The sheep country looks like steep sheep country everywhere, and reminded me of Wales and Scotland, even to the extent of carrying scrubby patches of brilliant yellow-flowered gorse – which, of course, is a troublesome introduction from Europe. There are so many other Europeans on these islands, not just Smiths and Joneses in suburban villas, but oaks, sycamores, elderberries, and implacable ivy. They compete for space with other native trees, including the New Zealand red beech, Nothofagus fusca, with its delightfully delicate little leaves and graceful habit. I could not help feeling that a coarse and unthinking hand has been at work, interfering with the landscape, scrubbing forests out, planting weeds. This is grossly unfair to the New Zealanders, the kindest people on earth.

      Podocarp trees are in a sense ‘survivors’ from the time of Gondwana. These trees are found in Australia, New Caledonia, South America, and Sub-Saharan Africa – one or two genera are even in common between New Zealand and the Andes. Gondwana may have split into its separate pieces, but the identity tags of its former inhabitants were not redesigned so easily. These Gondwanan coniferous trees, with their relatively large leaves and bright berries, do have a very special appearance, at least to a European accustomed to pines and firs with their dry-looking cones. A botanist would remind me I should really describe the berries as ‘fleshy peduncles’ because they carry exposed seeds at their tips. On the wet west coast of the South Island near Karamea, I walk into a podocarp forest where dampness rules. Everything that could be is covered in moss, epiphytes or filmy ferns. They clothe the trunks and branches of trees in a creeping, delicate and close-fitting cloak of tiny green leaves. Inconspicuous orchids are there somewhere, perched on branches, sporting small yellowish flowers, the antithesis of tropical showiness. Where light breaks through the canopy, tree ferns erupt like green fountains perched on shaggy stems, adding ebullience to the primeval atmosphere. Little brown birds with bright little eyes – tom-tits New Zealanders call them – pipe tamely from exposed twigs hoping that these clodhopping visitors might disturb insects for their supper. Trunks of the podocarp totara tree soar upwards, while the rimu – the most elegant of its family, with weeping, cypress-like branches – breaks through the canopy like drapes. The wood of this tree is so hard that the heart is still sound for working from trunks lying on the ground years after the outer layers have rotted. The more familiar southern beeches (Nothofagus) are unsuitable for major construction since they rot from the inside out, but they also have a Gondwanan signature, following closely the pattern of the podocarps. I recall that Charles Darwin observed how the natives in Tierra del Fuego ate a curious fungus looking like a cluster of yellow golf balls that grew on southern beech branches. The fungus was named Cyttaria darwinii by Miles Joseph Berkeley, the great nineteenth-century mycologist who worked out the fungal cause of the Irish potato blight. Further species of the same fungus were discovered, but they only grew on southern beeches: fungi can be choosy. The Gondwana legacy even applies to soft, edible fungi that would never stand a chance of being preserved as fossils. Biologists must have their wits about them if they are to understand the complexity of the past.

      New Zealand took away its package of Gondwanan plants as the continent broke up. Later, it was colonised by birds, and they evolved in isolation to produce a host of endemic species. Some are almost comical, like the kakapo, a ground parrot of remarkable stupidity (and now a threatened species), and the kea, a mountain parrot of legendary intelligence and a fondness for eating the windscreen wipers of cars exploring the Alps. It is said that keas can be found solving crossword puzzles left behind by tourists. Other birds became intimately involved with perpetuating the podocarp forest by swallowing and distributing their seeds. Some still remain, singing sweet songs high in the canopies of the stately stands that survive. Many scientists believe that at some stage in New Zealand history the sea level rose to a point where mammal species could not endure and breed. Today, it has no endemic terrestrial mammals. Whatever happened, nobody could question the fact that this antipodean island represents the acme of avian evolution in the absence of serious mammalian competitors. The loss of the ability to fly is common – why bother to take to the air when you can safely amble about in the bush? The kiwi is the amiable emblem of the country; a variety of kiwi species show the fecundity of this ground-dwelling option. None is safe for the future. The largest flightless bird that ever lived, the moa, lived in huge numbers in New Zealand. A Brobdingnagian ostrich, it was meat on legs for the first human invaders, who undoubtedly hastened its extinction.^* In the Karamea forest I see the dark entrance to cave systems perforating Honeycomb Hill from which dozens of moa bones have been recovered, and marvel at a sudden vision of an island swarming with the giant birds. If only we could turn back the clock. So many New Zealand bird species are either extinct or threatened. The new generation of New Zealanders are almost neurotically aware of what human interference has done to the natural environment. The introduction of the possum from Australia was a particular disaster, since these aggressive vegetarians seem to particularly relish New Zealand tree flowers. They threaten the livelihoods of all the nectar sippers and honey eaters among the bird species. The restocking of offshore islands with native birds in a rat-free, possum-free and cat-free environment seems to be the best option at the moment. It is at best a despairing attempt to store away from further trouble a remarkable history running into millions of years.

      I have to understand New Zealand’s long history before my search for an animal that has survived from a period even earlier than the first appearance of the horseshoe crabs. My quarry is the velvet worm. This creature will help us climb downwards to a still lower branch of the evolutionary tree. George Gibbs from the University of Wellington is my guide. He knows the secretive ways of these elusive animals. We drive out along Route 1, west of Wellington on the southern edge of the North Island, prior to walking up the Akatara Ridge along a small country track. The whole area was milled in the 1930s and 1940s so the mature podocarp forest has all gone, but there is secondary growth of tree ferns and rimu and Protea in a dense thicket. Some of the common native birds have adapted to the new circumstances. We hear the distinctive whistle and churr of the tui as we park the car. New Zealand birds usually have a distinctive and attractive song, even those that are unspectacular to look at. As we walk up the track I notice another survivor, the lowly herb Lycopodium, growing on the bank, a plant we shall meet again. It is a steady climb, though hardly taxing. Towards the top of the track the landscape opens out into gently rolling, wooded farmland. A scattering of cows and white sheep graze on the cleared, grassy hillsides, and dotted among them are Californian pines. The wind blows through the trees with a sound like the gentle crash of waves. The ‘old homestead’ proves to be an antique wooden building in the bottom of a small hollow surrounded by a circle of ageing pine trees. George locates the bleached remnants of rotten pine logs lying on the ground nearby. For some reason they had not been tidied away after felling, so they have had the opportunity slowly to break down in situ. Selecting one log, it soon becomes apparent that inside its pale exterior the decaying wood is rusty red and fibrous. George starts beating at it with a small mattock brought along especially for the purpose. I cannot help leaning expectantly over his shoulder. Each hack of the instrument beats away ten million years of geological time. Can the velvet worm be hiding inside this curious sarcophagus? Where is its time capsule?

      But the first log yields nothing. A second log is soon under attack. It seems softer somehow, more decayed. As the wood splits easily apart tiny white termites are exposed to the air, looking something like pallid ants, almost transparently delicate. They move slowly, as if stunned by being exposed suddenly to bright light: they are creatures of habitual darkness. Their little antennae can be seen waving furiously. Termites are wood eaters hiding deep inside the log, living in chambers they make running along its ‘grain’. We had opened up their secret world. And then we see there’s something else, something caterpillar-like, hiding in the termites’ tunnels. It shrinks away as if it does not want to be seen, or as if light is somehow an embarrassment to it. George coaxes it expertly into full view: it’s the velvet worm!

      This is the creature we had come all this way to find: Peripatus novae-zealandiae to give it its scientific name. Because it does not move very fast, it proves relatively easy to catch and bring out into the light. It is indeed about the size of a very large caterpillar, light brownish and with a stripe running down its СКАЧАТЬ