By Chris Clarke
Endangered species news hardly ever comes with happy endings. But on a popular tourist island off the California coast, a frankly endearing wildlife species has come back from the verge of extinction in the last decade with a little help from its friends.
The Catalina island fox is one of six subspecies of Urocyon littoralis that inhabit the Channel Islands off the Southern California coast. Like many island species, island foxes are in trouble. Foxes on Santa Cruz, San Miguel, and Santa Rosa islands have been in decline since the 1990s, mainly due to predation by golden eagles.
But it was an outbreak of distemper 15 years ago that nearly wiped out Catalina's foxes: a population of something like 1,300 foxes crashed to around 100 individuals. A strain of distemper usually found in raccoons had made it to Catalina somehow. Vaccines were ineffective: the distemper shots administered to pets would actually infect foxes with the highly contagious virus. Things looked bleak.
Island foxes are smaller than their mainland gray fox cousins. The Catalina island fox, the largest of the six subspecies, is about the size of a small housecat. The foxes' varied diet consists of rodents and other small mammals, birds and eggs, shellfish, and lots of fruit.
Listed as Threatened under the California Endangered Species Act since 1971, the Catalina island fox was listed by the feds as Endangered in 2004, along with its cousins on the three other islands where its populations had crashed. That listing came five years after the fox's numbers took a nosedive, in response to a suit by the Center for Biological Diversity and others.
The virus can survive in mainland wildlife populations without killing entire species off, but that's because mainland animals are continually exposed to the disease and have evolved resistance. Stuck out on their island paradise twenty miles off Long Beach, Catalina island foxes have had no reason to evolve the ability to survive distemper.
California's Channel Islands are unique evolutionary laboratories. More....