Key to any solution are the islanders who live in the neat little town of San Juan Bautista on Robinson Crusoe, the only island inhabited year-round. Domesticated cats ruled theirgardens during a recent visit by The Associated Press, and while most townspeople have agreed to sterilize their pets, many more cats are loose in the jungle.
U.S. ornithologist Erin Hagen, who has spent 10 years studying the hummingbirds, said few islanders are willing to abandon their pet cats or give up goat and rabbit meat for their dinners.
"There are people who are making the decision to live without these invasive animals, and others who are very attached to their pets, and others who like to go out hunting," Hagen said.
Chile has protected 96 percent of the territory as a national park since 1935, but the budget "is insufficient, without a doubt," said Ivan Leiva, who runs the park for the state-owned forestry corporation. "The problem is growing and defeating us."
Leiva, whose office is surrounded by small gardens and makeshift greenhouses, has made each of his eight park guards personally responsible for two species of particularly threatened plants. The guards monitor their charges, note when they flower and seed, and confront challenges that might arise.
Such tactics worked with the Dendroseris gigantea, a member of the asteraceae family whose broad, long-stemmed leaves were munched to the nubs by wildly propagating goats.Leiva marshaled an international group of biologists to prevent its extinction. They kept vigil throughout the year, measuring weather and soil conditions and managing to collect enough seeds to produce 50 more trees. Most now grow in the park's gardens, while 15 have been planted around the "mother" tree.
An earlier six-year, $2.5 million effort eliminated goats and rabbits from Santa Clara, an islet not far from town. Islanders were paid for each pelt and even provided with replacement bullets.
Goats were introduced by the Spanish in the 1600s to provide food for passing sailors, and their meat helped save the life of Alexander Selkirk, the marooned Scottish sailor whose four-year ordeal on the main island is widely believed to have helped inspire Defoe's 1719 castaway novel.. On the island Chile later named Robinson Crusoe, goats have been contained to a manageable area, but rabbits and rats run wild.
Meanwhile, on Alejandro Selkirk, the most remote of the islands, thousands of wild goats are destroying the habitat of the Rayadito de Masafuera, a small ovenbird whose numbers have dwindled to about 550.
Hunting down these animals on that island's steep slopes would be impossible by foot, but Chile can follow the lead of Ecuador in the Galapagos, where helicopters were used to eliminate wild goats and pigs from a much larger area, said Arnal.
"Using helicopters for eradication and restoration is to island conservation what the introduction of penicillin was to medicine," Arnal said. "These goats aren't going to die off naturally until they've eliminated all of the plants and the island is turned into a desert where there's nothing left to eat."
Eva Vergara is on Twitter: http://twitter.com/evergaraap
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