Channel Islands foxes have made the fastest recovery for any mammal listed on the endangered species list, U.S. wildlife officials said Friday.
The U.S. Fish and Wildlife Service said in an announcement that it plans to remove the San Miguel, Santa Rosa and Santa Cruz Island subspecies, all native to California's Channel Islands, from the Endangered Species Act list.
Wildlife officials and conservationists have worked for years to boost the fox population, in part by eliminating or controlling predators and disease, according to the wildlife service.
“Part of the wonderful story about this recovery is the entire ecosystem was put out of whack through primarily DDT being put into the environment,” Steve Henry, field supervisor of the U.S. Fish and Wildlife's Ventura office, told KPCC.
Henry said that DDT diminished the natural population of bald eagles on the islands. Along with the DDT, non-native species were introduced, like the golden eagle — a species whose diet consisted of eating other non-native species. Once non-native species were removed, they became one of the foxes' primary predators.
“We were able to remove golden eagles from the island and reintroduce bald eagles to restore the ecosystem, and upon that restoration, the island fox flourished,” Henry said.
The bald eagle diet consists mostly of fish and carrion, which allows for the Channel Island fox to return to its position as the apex predator in the ecosystem — keeping other populations, like non-native rats, in check, Henry said.
They also vaccinated foxes against canine distemper (a viral disease) and bred foxes in captivity before releasing them back into the wild.
In its statement, Fish and Wildlife also said it's proposing to change the status of Santa Catalina Island foxes from endangered to threatened.
"The speed at which these subspecies have recovered points to the strength of the [Endangered Species Act] in focusing conservation attention and catalyzing recovery actions, and demonstrates what we can achieve together," Fish and Wildlife director Dan Ashe said in a prepared statement.
Island foxes have been listed under the Endangered Species Act since 2004.
The foxes have now bounced back from a nearly 90 percent reduction, recovering to a self-sustaining level, officials said.
The Catalina Island subspecies, however, could still be threatened in the event of a disease outbreak.
A 60-day comment period on the proposed action opens on Tuesday, when the rule is scheduled to be published in the Federal Register. Comments can be submitted to firstname.lastname@example.org and more information on the rule can be found at the Fish and Wildlife website.
This story has been updated.