The once-pristine Channel Islands are under attack from a non-native population of feral pigs.© Chuck Graham
But now a four-footed menace has them under siege. Feral pigs, brought to the archipelago in 1853, are the only holdovers from the islands’ ranching days, which ended in 1990. The herds of cattle, horses and sheep that once inhabited the islands have left their mark on the chain, sometimes referred to as “the Galapagos of the North.” But the four-legged rototillers on Santa Cruz Island, the largest of the islets, have the greatest impact—even on neighboring Santa Rosa and San Miguel, where there are no pigs.
“We want to be pig-free,” proclaims Diane Divine of The Nature Conservancy. “The focus of the National Park Service and the Conservancy is to protect what’s out there, our California heritage.” Approximately 4,000 pigs are rooting up endemic flora like the island oaks and manzanita groves, and they’ve also lured mainland-based golden eagles, which have in turn discovered that the endemic island fox is as easy a kill as a piglet. “Golden eagles are making day trips over to the islands,” says Tim Coonan, terrestrial biologist for the park service. “They’re decimating the fox populations on Santa Rosa and San Miguel.”
The feral pig population will be hunted until they’ve been extirpated. Nearby Santa Rosa Island took a year and a half, from 1991 to 1992, to eradicate its pigs. “Their reproduction is very responsive to the weather,” says Kate Faulkner, chief of resource management for the Channel Islands National Park. “During the dry season they have a high mortality rate.” Eliminating feral pigs from the park will cost an estimated $1 million.
Faulkner says the Santa Rosa pigs were wiped out with a force of gun-toting wildlife biologists; a similar method may be used on Santa Cruz. Stephanie Boyles, a wildlife biologist representing the People for the Ethical Treatment of Animals (PETA), says that the group hasn’t taken a position on the Channel Islands plan, but has opposed Nature Conservancy eradication efforts when they involve the use of painful snares.
Years of overgrazing have taken a toll on the fragile native ecosystem, but there is hope in reclaiming the islands. “I feel we’ve gone from an era of ranching to an era of restoration,” says Faulkner.