During a short five-year period in the 1990s the island fox populations on the northern Channel Islands declined by over 90 percent due to predation by golden eagles.
Today, less than a decade after four of the six island fox subspecies were listed as federally endangered, biologists believe they are on the cusp of meeting the criteria for delisting.
“The decline of the island fox population was so severe it caused biologists to shift from tracking fox populations to worrying about the fate of individual foxes,” said Channel Islands National Park Superintendent Russell Galipeau. “We are thrilled with this rapid recovery which is one of the quickest recoveries of an endangered species in the history of the Endangered Species Act.”
At the lowest point, in 1999, there were only 15 foxes each on San Miguel and Santa Rosa Islands—a catastrophic drop in fox numbers from 450 and 1,500 respectively. In 2000 there were less than 70 foxes on the largest Channel Island, Santa Cruz. Today there are about 1,300 foxes on Santa Cruz Island, 500 on San Miguel Island, and 600 on Santa Rosa Island with each population having a 90 percent annual survival rate.
Saving the island fox from the brink of extinction was only one facet of a decade long restoration effort to return balance to the ecosystem on Santa Cruz Island. Between 2000 and 2006, 44 golden eagles were carefully live-captured and relocated successfully to the eastern Sierra Nevada. Today, they are infrequent visitors due to the absence of feral pigs.
From 2005 to 2006 over 5,000 nonnative feral pigs were eradicated on Santa Cruz Island. Feral pigs had attracted golden eagles as a new predator to the island, rooted up vegetation including nine endangered native plants, caused massive erosion, spread invasive weeds, and destroyed ancient Chumash archaeological sites.
A five year program to reestablish bald eagles, which included the release of 60 eaglets from 2002 to 2006, has yielded over 40 resident birds on the northern Channel Islands. This year’s breeding season there are at least six known active bald eagle nests on the northern Channel Islands.
Recovery of vegetation, resulting from removal of sheep and pigs, also contributed to improving habitat and supporting the recovery of the island fox.
“This recovery is a terrific example of what can happen when people roll up their sleeves to restore an ecosystem,” said Dr. Scott Morrison, lead scientist for The Nature Conservancy in California. “So many scientists, managers, and partners had a hand in this and are celebrating with us today.”
The Nature Conservancy and the National Park Service are continuing their partnership to preserve resources on Santa Cruz Island. In 2011 they began a project to restore what was once the largest coastal wetland on the Channel Islands at Prisoners Harbor on Santa Cruz Island. The project, which extends over nearly 60 acres of land, restores approximately four acres near the shore and nearly one mile of stream habitat in the valley improves habitat for native plants and wildlife such as the Santa Cruz Island fox, island scrub-jay, and migratory waterfowl.
To view a restoration film “Restoring Balance—Santa Cruz Island” visit:http://www.nps.gov/chis/photosmultimedia/multimedia.htm
This publication is available on line at: www.nps.gov/chis/parknews/newsreleases.htm