February 12, 2016 ~ BREAKING NEWS ~ USFWS Announces Recovery of Channel Island Fox:
The Island Fox, a cat-sized carnivore, descendant of the gray fox, is native to six of the eight Channel Islands of California, and is considered an endangered species on four islands: San Miguel, Santa Rosa, Santa Cruz and Santa Catalina. The foxes are believed to have "rafted" to the northern islands between 10,400 and 16,000 years ago. They are found on the Channel Islands and no where else in the world. Each of California’s Channel Islands are unique and, like the Galapagos Islands, a treasure of biodiversity.
Island foxes vary genetically and in coloration, size, muzzle shape, and tail length from island to island. Each population is considered a separate subspecies, unique to the island it lives on, reflecting its evolutionary history:
San Miguel Island Fox (Urocyon littoralis littoralis) - typically second largest in size, shortest tail (average 15 vertebra).
Santa Rosa Island Fox (Urocyon littoralis santarosae) - average the longest ears.
Santa Cruz Island Fox (Urocyon littoralis santacruzae) - typically smallest in size, shortest legs.
Santa Catalina Island Fox (Urocyon littoralis catalinae) - typically largest in size, longest tail.
San Nicolas Island Fox (Urocyon littoralis dickeyi) - may be lighter in color, typically longest legs, most number of bones in tail (average 22 vertebra).
San Clemente Island Fox (Urocyon littoralis clementae)
The island fox is significantly smaller than the gray fox and perhaps the smallest fox in North America. Adults are typically 12-13 inches high at the shoulder, 23-27 inches long from nose to tail tip, weighing 3-6 pounds. Males are slightly larger than females. Their small size is an adaptation to the limited resources available in the island environment. Their lifespan is 4-6 years; some individuals have been known to live up to 15 years.
Channel Island foxes mate for life and breed once a year. Pairs come together in late winter, find a den location, and mate between February and March. The pups are born in late April, blind and helpless, about the size of two AA batteries. They stay in the protection of the den, cared for by their parents, until early June, when they emerge and begin their journey to adulthood.
By September, most pups head out to find their own territory. Female pups may stay near their parents’ territory, while male pups tend to travel a distance before setting up their own territory. A mated male and female may have overlapping territories. Island foxes protect their territories and sometimes they can be heard barking or yipping at other foxes coming into their territory. Territorial disputes can be serious, injury from these disputes can include ripped and torn ears, leg wounds and even death.
Island foxes are omnivorous, eating both plants and other animals. They eat a large amount of insects, island deer mice, reptiles, ground-nesting birds, grasshoppers, crickets, and fruit from native plants such as summer holly, cholla cactus, rose, sumac, and nightshade. Their diet changes with the seasons.
The island fox is not intimidated by humans, although at first could show aggression. It is quite easy to tame and is generally docile. They communicate using auditory, olfactory and visual signals. A dominant fox uses vocalizations, staring, and ear flattening to cause another fox to submit. The island fox marks territory with urine and feces. Island foxes moult twice a year, gaining a winter pelage in October to November, which is replaced with a less dense summer pelage during March to May
Twelve years ago, four subspecies of Channel Island foxes almost went extinct from introduced diseases and predation by golden eagles. The island foxes on Santa Catalina became endangered when a wild North American raccoon was accidentally transported on a boat and escaped onto the island in the late 1990s. Canine distemper virus, a fatal dog disease, was passed from this raccoon to the Catalina island foxes. By 2000, nearly 90% of the Catalina population had died from the distemper virus.
In the mid-1990s biologists began to notice a decline in fox populations. By 2000, the northern populations were crashing toward extinction:
San Miguel - 1994 estimated 450 foxes, by 2000 only 15 individuals remained.
Santa Rosa - 1994 estimated 1,780 foxes, by 2000 only 15 individuals remained.
Santa Cruz - 1994 estimated 1465 foxes, by 2000 only 62 individuals remained.
This rapid population decline was due to an imbalance in the ecosystem. The island fox is the largest mammal native to the islands; it is the top terrestrial predator. It did not know how to protect itself when a new predator came to the islands. Historically, bald eagles also lived on the northern islands and on Santa Catalina Island. This large bird of prey specializes in eating fish and sea birds and did not prey on the island fox. As a territorial bird, it kept other eagles from nesting on the islands.
After WWII the introduction of DDT into local watersheds and the marine environment, caused the extinction of the bald eagle on the Channel Islands. DDT is a chemical insecticide that caused the eagles to lay eggs with thin shells, which crushed under the incubating parent. Large scale ranching on the islands introduced plant-eating animals: goats, sheep, pigs, as well as deer and elk for hunting. These animals heavily impacted native plants that the island fox depended on. Ranching had limited success on the islands and the domestic animals became feral or wild. The young pigs, goats and deer, were all potential food sources for another large bird of prey, the Golden Eagle. After DDT was banned in the 1970s and ecosystems began to recover, golden eagles moved out to the northern Channel Islands to prey on the introduced animals and eventually, the island fox. From 1994-2000, golden eagle predation on island foxes was extreme. The golden eagle was eating the island fox into extinction.
Rapid response on the part of land managers at the Channel Islands National Park, Nature Conservancy and Catalina Island Conservancy, government agencies, and public and private organizations saved the four endangered island fox populations from extinction. Today, all populations are stable or increasing.
For more information on the Channel Island Foxes:
Friends of the Island Fox: http://www1.islandfox.org/ http://www.nps.gov/chis/naturescience/island-fox.htm http://www.defenders.org/channel-island-fox/basic-facts
We made our first day trip to Santa Cruz Island in October 2011. We spent the day hiking around the island with zero fox sightings. As we were heading back to wait for the return ferry, with less than 30 minutes on the island, a fox crossed our path, posed for a photo, and continued on his way. We scrambled to position our cameras and snapped a few shots, thrilled with our 12th hour fox visitor.
We went back to the island in May of 2012, again just for the day, again the foxes proved elusive. Not one sighting. I got sea sick on the ride over in the morning and spent most of the day sleeping it off. Not a successful fox trip! We realized the best way to see foxes is to camp on the island. Which we did in June 2012.
Third time is the charm!!! We hit T-H-E- MOTHERLOAD of fox activity. What a thrill to see these wonderful creatures with their pups doing what Island Foxes do. Knowing that they can live their lives free from the fear of predation and with the protection of the humans that care for the islands and their ecosystems. We spent two wonderful days chasing and photographing the Island foxes. As if this experience wasn't wonderful enough, on our ferry ride home we were surrounded by a pod of hundreds of Common Dolphins: http://www.kimmichaels.com/recent/h4f33d04e#h4f33d04e
What a fulfilling two days!!!