A little more than a decade after being listed as endangered, three subspecies of miniature foxes native to California’s Channel Islands have made a full and epic recovery, federal authorities said Thursday.
Their comeback from the very brink of extinction is the fastest of any mammal in the 43-year history of the Endangered Species Act, the U.S. Fish and Wildlife Service and the Interior Department said.
“It’s remarkable to think that in 2004, these foxes were given a 50 percent chance of going extinct in the next decade,” Dan Ashe, the Fish and Wildlife Service director, said in a statement. He said successes at reversing endangered species’ population declines were “coming faster and faster now because we’re learning how to do it better.”
The subspecies removed from the endangered species list Thursday are those from the islands of San Miguel, Santa Rosa and Santa Cruz. A fourth from Santa Catalina Island continues to see populations increase and has been reclassified from endangered to threatened.
In the late 1990s, these isolated foxes, which evolved to be top predators of their island ecosystems, saw populations plummet by more than 90 percent, mainly a result of predation by golden eagles that moved in to replace bald eagles, whose populations were decimated from exposure to DDT pesticide, according to authorities. Foxes on the island of Santa Catalina also were struck by an outbreak of canine distemper.
“The decline of the island fox, one of America’s rarest mammals, was rapid and severe,” National Park Service Director Jon Jarvis said in a statement.
On Santa Rosa, for example, 1,780 foxes were reduced to 15 individuals. Other islands saw similar declines.
As of last year, however, federal authorities estimated there were some 1,200 foxes inhabiting Santa Rosa, 700 on San Miguel, and 2,100 on Santa Cruz. On Santa Catalina, where disease remains a threat, the fox population hovers around 1,800, according to a release.
Island foxes are considerably smaller than their mainland ancestor, the gray fox. One theory, according to the National Park Service, is that foxes arrived on the islands thousands of years ago by “rafting” there on debris.
The population recovery, although speedy, was no easy feat. In addition to captive breeding and vaccinating foxes, authorities removed feral pigs from the islands, relocated golden eagles and re-established bald eagles, according to the Fish and Wildlife Service.
Experts said the record-breaking comeback could serve as a template for other species.
“Many aspects of this recovery effort ― from its scientific rigor to the collaborative enterprise that drove it ― can serve as model to advance conservation elsewhere,” Scott Morrison, director of conservation science at The Nature Conservancy, said in a statement.