The article incorrectly listed in one reference the three islands where populations of island foxes were endangered but are now recovering quickly. The three islands are Santa Cruz, Santa Rosa and San Miguel
Restored Island Offers Hope for Other Trouble Spots
Monday, March 30, 2009
SANTA CRUZ ISLAND, Calif. -- The tiny fox scurrying across the lush green landscape, whose ancestors probably floated here 18,000 years ago on storm debris, wore an unlikely testament to its survival in the wild: a radio collar.
The collar helped explain why the Santa Cruz Island fox, along with several other species scattered across Southern California's Channel Islands, are recovering from the brink of extinction. Even as habitat destruction and other pressures threaten plant and animal species across the United States, a concerted restoration effort is demonstrating that it is possible to rebuild an ancient ecosystem that had disintegrated because of human habitation.
It is uncertain whether the success achieved on this 160-mile-long archipelago can be easily replicated on the mainland. But it helps to prove that just as isolated island habitats can fall apart when humans ignore the consequences of their actions, they can also rebound quickly under ca reful scientific management.
"Without intervention, the island fox would have perished, a one-of-a-kind place would have disappeared and the native habitat you're seeing flourish now would be gone," said Lotus Vermeer, director of the Nature Conservancy's Santa Cruz Island Preserve.
Santa Cruz is the largest of the eight islands, a grouping that collectively is home to more than 2,000 land and aquatic species, of which 145 live nowhere else on Earth. Channel Islands National Park incorporates five of them -- Anacapa, Santa Cruz, Santa Rosa, San Miguel and Santa Barbara. The Nature Conservancy owns 76 percent of Santa Cruz and runs it jointly with the National Park Service. The Navy controls San Clemente and San Nicolas, and a private group, the Catalina Island Conservancy, oversees Santa Catalina.
The islands' distance from the California mainland, which ranges from 12 to 70 miles, allowed a variety of distinct species to evolve there over tens of thousands of years. They include the island scrub-jay on Santa Cruz, the Anacapa deer mouse, the unique Santa Rosa subspecies of the Torrey pine and the Santa Catalina Island ironwood, a member of the rose family.
An array of birds, including the rare Xantus's murrelet, the California brown pelican and Cassin's auklet, also depend on the islands for shelter and sustenance.
"We pretty much would not have breeding seabirds in Southern California if it was not for these islands, because they're predator-free and free of disturbance, and close to a good food source," said Kate Faulkner, chief of natural resources management for Channel Islands National Park.
But this was not always the case. In the 1800s, people brought alien species to the islands, including sheep, pigs, cattle, deer, elk, cats and rats. The animals distorted these isolated ecosystems in myriad ways by destroying vegetation and attracting still more predators, which decimated the archipelago's six distinct subspecies of island fox and other native animals.
Golden eagles, lured by the easy prey of baby feral pigs, also feasted on the foxes. "They were picked off by golden eagles like popcorn," Vermeer said. The three subspecies on Santa Cruz, San Miguel and Santa Cruz declined by more than 90 percent by the late 1990s, and all three were listed as federally endangered in 2004.
In the 1980s, the Nature Conservancy, the Park Service and the Fish and Wildlife Service jointly launched a restoration program on Santa Cruz that was replicated on the other islands. Over a decade, the organizations killed 40,000 sheep and a few thousand cattle on Santa Cruz, and by 2006 they had also eliminated 5,036 feral pigs. Since 1999, managers have captured and relocated 32 golden eagles, none of which have returned to nest.
The Conservancy placed radio collars on the 100 remaining Santa Cruz island foxes so it could track them weekly. Vickie Bakker, a Smith Conservation Research Fellow at the University of California at Santa Cruz, is doing computer modeling to monitor how the island fox population is expanding and determine when it will be out of danger.