Island Fox (Urocyon littoralis)
Fox pup

In June 2014 the Institute for Wildlife Studies announced to the Island Fox Working Group that it was initiating a petition to delist three of the four subspecies of island fox, and downlist the remaining subspecies. This action was being taken due to the amazing recovery of the populations across all of the affected islands. The US Fish and Wildlife Service (USFWS) later approached IWS and discussed their moving forward with an internal process to do the delisting, rather than have IWS submit a petition. IWS agreed and in February of 2016, the USFWS proposed delisting three island fox subspecies on the northern Channel Islands due to population recovery (press release). The San Miguel, Santa Rosa and Santa Cruz Island fox subspecies would be removed from the endangered species list, while the status of Santa Catalina Island foxes would be downgraded to “threatened” status. While the Santa Catalina Island subspecies had undergone essentially a complete recovery, attaining its estimated pre-decline population size, there is a greater potential risk for disease introduction given the number of island residents and the large number of annual visitors to the island. In August 2016 the delisting was officially announced (press release), and the three island fox subspecies became the fastest mammalian species to ever reach recovery and be removed from the endangered species list.

IWS is a member of the Island Fox Working Group, which helped develop the Recovery Plan for the four subspecies. The group consists of agencies, landowners, academics, and non-profits dedicated to conserving the island fox.

In the late 1990s, three of the six island fox subspecies (found on Santa Rosa, San Miguel and Santa Cruz islands) suffered marked population declines caused by disease and predation by golden eagles (Aquila chrysaetos), and the Santa Catalina Island population was devastated by the introduction of canine distemper. In 2000, IWS and the Center for Biological Diversity petitioned the USFWS to list the four subspecies under the Endangered Species Act. The Department of Interior took action and on March 5, 2004 the subspecies were listed as “endangered”.

At the time of the listing, IWS was already involved in conservation actions, working with the Catalina Island Conservancy, The Nature Conservancy and the National Park Service. Our biologists and veterinarians led the effort to breed captive foxes on Santa Catalina and Santa Cruz islands, release captive-bred foxes into the wild, test an experimental canine distemper vaccine, and monitor the wild fox populations on those islands. At the same time we conducted annual population monitoring of non-federally listed subspecies on San Nicolas and San Clemente islands.

The intense recovery actions of captive breeding/reintroduction, along with golden eagle removal have concluded. Emphasis is now on mortality monitoring (via radiocollars) and monitoring for population size/density using spatially explicit capture-recapture methods. IWS also formulated epidemic response plans for all of the island except San Nicolas, to assist land managers should significant predation or disease occur. We continue to be actively involved in annual monitoring of foxes on San Clemente and San Nicolas islands.



Population Trends (y axis = Number of Foxes; x axis = Year)

Click on the island names to learn more about recovery actions on each of the islands.

San Miguel Island Santa Rosa Island
Fox pop declines, then grows 1993-2014 Fox pop declines, then grows 1993-2014
Santa Cruz Santa Catalina
Fox pop declines, then grows 1993-2014 Fox pop declines, then grows 1993-2014
San Nicolas San Clemente
Fox pop declines, then grows 1993-2014 Fox pop declines, then grows 1993-2014


Island Fox Working Group 2015 Update

Recovery Plan for Four Subspecies of Island Fox (San Miguel, Santa Rosa, Santa Cruz, and Santa Catalina islands) Recovery Plan.pdf

Channel Islands National Park Island Fox Page

Friends of the Island Fox