The Channel Island fox is a diminutive species of fox endemic to the Channel Islands in Southern California. The island fox was listed as endangered under the Endangered Species Act (ESA) in 2004 due to predation by non-native golden eagles, habitat degradation and disease introduced by mainland species entering the islands.
This installment of Species Spotlight takes a closer look at partnership-driven conservation efforts that brought the island fox from the brink of extinction in 2004 to a delisting due to recovery in 2016. This effort represents the fastest successful recovery for any ESA listed mammal in the United States.
In the early 1990s scientists began to notice a dramatic decline in island fox numbers. Partners from the National Park Service, the Nature Conservancy, the Catalina Island Conservancy and numerous other groups recognized the dire situation of the island fox and initiated a captive breeding program in 1998.
Following the 2004 island fox ESA listing, a golden eagle capture and relocation program was initiated. The program was designed to remove golden eagles – a predator to which the fox had no natural adaptation – and replace them with bald eagles. Given bald eagles’ preference for aquatic prey and historical habitation of the islands, they do not present a significant predatory threat for the island foxes.
Following the golden eagle relocation program, partners began the process of removing introduced mule deer and elk and feral goats, pigs and sheep. These introduced species were severely degrading habitat and inviting a suite of invasive plants to take hold on the islands. The National Park Service and the Nature Conservancy were able to successfully remove a variety of introduced mammal species from the islands, which allowed native vegetation in critical island fox habitat to rebound.
Canine distemper, a disease introduced to the islands by non-native dogs and raccoons, was responsible for nearly decimating the island fox population on Santa Catalina Island in the 1990s. In response, federal, state and private groups assisted in rounding up the remaining foxes and administering distemper and rabies vaccinations on all of the islands containing foxes. The diseases had not yet reached the other islands containing foxes, but precautionary vaccinations were administered to “core populations” of foxes on all islands to ensure that there will be sufficient survivors if the diseases were to arrive.
On Aug. 11, 2016, the U.S Fish and Wildlife Service (FWS) announced the final delisting of the island fox. At the time of the 2004 endangered listing, the FWS estimated that there were fewer than 100 foxes remaining on all of the Channel Islands. By 2015, that number had reached roughly 4,000.
The FWS will continue to monitor the status of the island fox through microchips, radio tracking collars, annual counts and a continued vaccination program. Interior Secretary Sally Jewell remarked in a press release that “the island fox recovery is an incredible success story about the power of partnerships and the ability of collaborative conservation to correct course for a species on the brink of extinction.”
Species Spotlight, a case study series examining the challenges and opportunities in species conservation, is part of the Western Governors' Species Conservation and Endangered Species Act Initiative, the Chairman's Initiative of Wyoming Gov. Matt Mead.
More in the Species Spotlight series: