Small enough to fit in the palm of your hand, the tiny Channel Island fox has faced big problems. This unique species lives only on the Channel Islands located off the coast of Southern southern California, where they are believed to have evolved from the gray fox about 16,000 years ago. Despite its historic tenacity, the island fox is critically endangered.
In 1999, a major decline in the island foxes occurred on Santa Catalina Island. Scientists were concerned that canine distemper may have been the cause and that other disease outbreaks could wipe out the remaining populations on each island. In an effort to save this species, four islands began captive breeding programs, but little was known about the survival rate of the animals released from these programs or their ability to combat disease.
Using Morris Animal Foundation funding, Drs.doctors Jonna Mazet, Linda Munson and Deana Clifford of the Wildlife Health Center at the University of California–Davis’ Wildlife Health Center evaluated the captive-release program on Santa Catalina Island. The results were encouraging. The animals who were born into captivity and then released have high survival rates — about 89 percent compared to wild populations at 95 percent — and no evidence of illness due to infectious disease. The information gleaned from this program is now being used to develop effective management and release strategies on the other islands.
The team also determined that the island foxes had been exposed to numerous infectious diseases carried by dogs and cats. Population managers are using this information to design vaccination programs to protect the remaining foxes and to implement policies regarding domestic animals on the islands.
Island fox numbers are now increasing on four of the Channel Islands, with the population on Catalina more than doubling, thanks in part to the information learned from Foundation-funded studies. Although the island foxes are still endangered, scientists and managers are now optimistic about the population’s survival.
