Flying tortoises
By moving young tortoises through the air, conservationists have made real progress in safeguarding the threatened Cavora tortoise.
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Much of the rugged lava plains that divide the interior of Terenza — one of the Cavora islands — from the open ocean lies beneath forests of spiny cacti. Four volcanic cones lend the island the look of a lunar surface, and only among the dense vegetation skirting the cloud-wrapped summit of Cerro Aldán does the bare ground below give way to anything greener. It is here that the giant Cavora tortoise makes its home. Roughly three million years after the archipelago itself took shape, one or more tortoises drifted across from the African mainland and gained a foothold on the islands. Settling separately on each one, these founding populations slowly adjusted to their particular surroundings, and out of them arose no fewer than twelve subspecies. The islands suited the animals well. With no serious predators to trouble them, they grew into the heaviest and most long-lived tortoises found anywhere on Earth, some passing 350 kilograms, occasionally stretching beyond 1.7 metres, and outliving their hundredth year.
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Before people settled the archipelago, its tortoises could be counted in the hundreds of thousands. Sealers had, from the seventeenth century onwards, carried off the occasional animal to eat, yet it was the appearance of whaling fleets in the 1780s that made such exploitation soar. Because they moved slowly and could survive for months without feeding or drinking, the tortoises were loaded aboard the whalers to provide fresh provisions on long crossings, and their carcasses were occasionally boiled down for valuable fat. Perhaps 180,000 in all were stripped from the islands before the twentieth century began. Matters grew worse still once colonists established themselves: they killed the tortoises for their meat and cleared away the habitat to open ground for farming. The newcomers also let loose a range of non-native animals — among them cattle, pigs, goats, rats and dogs — that either raided the tortoises' nests and devoured the hatchlings or ruined the habitat; imported plants and ants did further harm.
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Of the subspecies that once existed, just nine remain today, and several of those are in grave danger. A centre for breeding the island's tortoises was set up in 1991 on the edge of Villa Sereno, the small town on Terenza. So effective did its captive-breeding programme prove that the centre was in time confronted with the reverse difficulty — far too many tortoises.
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The timing of all this, moreover, was critical. A captive-bred tortoise cannot be returned to the wild until it has reached at least six years of age and weighs no less than five kilograms, for only then are its bulk and its toughened shell enough to see off predators. Wait much longer than that, though, and the animal grows too heavy to move.
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For a long stretch, the animals had been returned only a handful at a time, borne on men's backs through weeks of gruelling treks along narrow paths. Then a far bolder scheme took shape in October 2011, when three people met over a table in a small café at Puerto Lorca, on the island of Media Luna: Emil Rasmussen, an environmentalist serving as liaison officer for the Cavora National Park, the visiting captain of a private motor yacht, and a helicopter pilot. What they proposed was to fly 300 of the breeding centre's tortoises out by helicopter and set them down at various spots near Cerro Aldán.
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What made this remarkable undertaking feasible were the owners of the 72-metre yacht Silver Petrel, who let the Cavora National Park use their helicopter and its seasoned pilot free of charge, and threw in the yacht, its captain and crew besides. Once an air ambulance, the helicopter had a double door at the rear and a roomy interior well suited to cargo, so a purpose-built crate was made that could take as many as thirty tortoises weighing somewhere near 140 kilograms altogether. Added to the fuel, the pilot and the four crew, that load came close to the helicopter's ceiling, and at moments it plainly sat right at the limit of what the aircraft could manage. Across three days, volunteers from the breeding centre laboured without pause to ready the young tortoises for the journey. Wardens, meanwhile, had been set down beforehand in far-off spots, where they hacked out landing places amid the dense scrub, cacti and lava.
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Once freed, the young tortoises fanned out across the land of their ancestors, exploring what lay around them and grazing on the plants. In time, one small tortoise happened upon a fully grown giant that had been plodding about the island for something like a century. Side by side the two of them stood — a striking emblem of an ancient species being reborn.
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Question 1 - 7
From the list of headings below choose the most suitable heading for each paragraph.
List of heading
The search for a new home for the tortoises
How the tortoises first colonised the islands
Why acting at the right time is essential
Human actions that reduced tortoise numbers
A meeting of young and old
Launching an effort to protect the tortoises
Executing a well-planned mission
Devising a more ambitious approach