Channel Island Fox (credit: Tim Coonan).
These endangered foxes are found on six (San Miguel; Santa Cruz; Santa Rosa; Santa Catalina, and not endangered on San Clemente and San Nicolas) of the eight Channel Islands off the coast of Southern California—and nowhere else. The subspecies on each island differ genetically and physically. For example, the foxes on San Miguel have shorter tails and one less vertebra. All of the island foxes are very small, about a foot high, two feet long with tail, and weighing between three and four pounds—smaller than the average house cat and some 20 percent smaller than the gray fox. Yet this is the largest native predator on the Channel Islands.
The six subspecies of the Channel Island foxes, found on six of the eight islands, are the result of changes that occurred since the foxes first got to this island chain between 10,400 and 16,000 years ago by “rafting” (floating on logs or other debris) from the coast of Southern California.
Initially, fox populations were located on the three northern islands, which were likely easier to access during the last ice age, when lowered sea levels united four of the northernmost islands into a single mega-island (Santa Rosae), and the distance between the islands and the mainland was reduced.
As sea levels rose and the Channel Islands separated, genetically distinct subspecies evolved on each. Archaeological records show that the Chumash Native American tribe made pets of the docile, inquisitive creatures, and likely introduced the fox to the southern Channel Islands, including Santa Catalina, about twenty-two to thirty-eight hundred years ago.
Foxes in Trouble
I first heard about the declining populations of island foxes in 2001 when I visited the Santa Barbara Zoo for a Roots & Shoots festival. One of the groups—the S.O.S. (Save Our Species) Roots & Shoots—told me about the project they had chosen: helping to publicize the plight and raise money for the endangered Channel Island foxes.
Will Van Santen and Spencer Steinberg from the SOS Roots & Shoots group preparing food for Island Foxes in the captive breeding program (credit: Gloria Van Santen).
Six years later, in Los Angeles, I met Susan Morris, parent leader of S.O.S.; Tim Coonan, Channel Islands National Park biologist, who directed the Island fox recovery program; Patricia Meyer, president of the Friends of the Island Fox nonprofit organization; and the S.O.S. members—Alexandra Morris, Larissa Rockney-Finger, Xander Rockney-Finger, Brianna Slade, Haley Slade, Simon Ettenger, and Kristen Pietro—three of whom have been with the project since 2000. They gave me a good deal of information about the history of the foxes, and their rate of decline on the northernmost islands.
On San Miguel Island, for example, there were above four hundred foxes in 1994: five years later there were no more than thirty left and it was decided to put radio collars on fifteen of them to try to determine the cause of death. Tim told me, “Of the first eight we collared in fall 1998, four had died of predation by March 1999. That’s when we began pulling the remaining foxes into captivity, and there turned out to be only fifteen foxes left.”
A New Predator—The Golden Eagle
It was found that four of the foxes had fallen victim to a newcomer, the golden eagle. Historically, bald eagles had soared over the Channel Islands, but they had vanished during the 1950s and 1960s, mainly due to DDT poisoning. After 1971, when the chemical was banned, bald eagles began to make a recovery on the mainland, but they did not reappear on the islands. And then in the 1990s, Tim told me, golden eagles appeared on the islands. Soon they increased in number, able to thrive in an island habitat where the composition of the undergrowth had been completely changed by the feral pigs that had been introduced by settlers years before. The problem is that golden eagles hunt small mammals, including foxes, whereas bald eagles are fish eaters.
After this proof of eagle predation, it was decided to capture all remaining foxes on San Miguel and Santa Rosa for captive breeding. At about the same time, large numbers of the foxes on Santa Catalina Island began dying of canine distemper, introduced by domestic dogs. By the end of the following year, 88 percent had been lost to this disease. Fifteen pairs were then trapped for captive breeding, and the progress of those remaining was closely monitored. By 2005, when it was clear that the remaining population in the wild was doing well, all the captive foxes were vaccinated and released. (Unfortunately, on Catalina—but not the other islands—the foxes also have to contend with traffic. Cars have killed a number of them in recent years.)
In 2006, the National Park Service and The Nature Conservancy jointly sponsored a program to exterminate the pigs on the islands. And another program saw the relocation of golden eagles and the reintroduction of the bald eagle to Santa Cruz Island, where two pairs bred.
Protection Through the Santa Barbara Zoo
Thane has written about the role played in the Channel Island fox program by Rich Block. He and Thane went to grad school at the University of Michigan’s School of Natural Resources “over thirty years ago, back when we both had hair,” said Thane. Currently, Rich is director of the Santa Barbara Zoo, which is working to protect key California endangered species including the California condor and the San Clemente fox. “It is,” said Thane, “one of the best small zoos in the world.” It got into the fox business in 1999 when it created the first zoo exhibit dedicated to Channel Island foxes.
Today the islands’ fox population is estimated at more than 240 animals, which is a significant comeback from less than 150 just a few years ago. Even so, Thane described the zoo’s work as never ending. “Veterinarians and researchers, from the Santa Barbara Zoo and others, are involved every week with the foxes, measuring their health through periodic physicals and monitoring their movements and behavior via radio collars. And vaccinations continue to play a principal role in this comeback effort. Currently, 75 percent of the wild population has been vaccinated against canine distemper to protect against future outbreaks.” As Rich Block put it, “This is the emergency room of the wildlife game. Some species take drastic measures to ensure their continued survival.”
