Surrounded by the magnificent blue waters of the Pacific Ocean, Santa Cruz Island, just 25 miles west of Santa Barbara, is the scene of a life-and-death drama that pits feral pigs against the dainty island fox. The introduction of non-native species to one of California’s isolated Channel Islands has led to the near extirpation of native species and the destruction of archaeological ruins dating back some 6,000 years.
The Nature Conservancy, which owns about 75 percent of the island, in cooperation with the National Park Service, which owns the other 25 percent, is leading a project to restore ecological balance to Santa Cruz and save the island fox from possible extinction, or at least from being listed as an endangered species.
This tangled web begins with the introduction of pigs to this 62,000-acre island in the 1800s when it was home to several ranches. The pigs, now wild, can number as many as 4,500 and root in the soil for their food. In the process, they destroy wildlife habitat and disturb historical sites belonging to the Chumash Indians, the island’s first human inhabitants. The disturbed landscape is ripe territory for sweet fennel, a European herb that has encroached on native island plants.
The pigs have opened the door to further upheaval by attracting golden eagles who feed on the piglets until they grow too large and then move on to the island fox, which is no bigger than a house cat. The resident population of bald eagles, which nested on the island and lived off fish and other marine life, plummeted during the 1960s presumably because DDT thinned their eggshells. Without these normally territorial birds, which make their homes on the island’s bluffs, the golden eagles have had a heyday.
The solution as planned by the Nature Conservancy’s project ecologist is far from simple. The golden eagles are being relocated to the mainland, while bald eagles are being reintroduced to the island. Meanwhile, the feral pigs are being hunted and the imperiled island fox is being bred in captivity to boost its population.
Finally, the fennel will be treated and removed, allowing native plants to recolonize these areas. Without the disturbed soil conditions created by the pigs, the fennel should be less invasive and more easily controlled.
If all goes as planned, the island will be restored to conditions that existed before it was transformed by ranches. This effort is one of the largest and most complex ecological restoration projects ever attempted in the United States.
U.C. Santa Cruz Currents
