The Santa Cruz Island Fox

The Santa Cruz Island Fox

by Nathan Mok

  Deep within the heart of California's Channel Islands lies the state's only unique carnivore, the Island Fox. The Santa Cruz Island Fox (Urocyon littoralis santacruzae) lives on one of those Channel Islands right off the coast of Southern California. As you can probably tell from its name, the Santa Cruz Island Fox comes from Santa Cruz Island, which is also the largest out of the channel islands. In addition to the Santa Cruz Island fox, there are 5 other types of foxes affected by the same struggles of extinction. The Islands they usually inhabit are Santa Cruz Island, San Miguel Island, Santa Rosa Island, Santa Catalina Island, San Clemente Island, and San Nicolas Island. They are found no where else on earth, except on their respective island that they are named after.

The Santa Cruz Island Fox is about the size of a house cat commonly seen as pets. At adult age, the fox stands at around 12-13 inches tall, extends about 23-27 inches long (from nose to tail tip), and weighs around 3-5 pounds. Compared to the other island foxes, the Santa Cruz Island Fox is generally the smallest in size. They are also said to be a relative cousin of the gray fox (Urocyon cineroargenteus).

Within this chart below shows the population change of the island foxes, linked to it’s respective island. It gives a pretty clear picture on how drastic changes took a toll on its population within a span of a decade or two.

Island/Subspecies	1994 Estimate	1999/2000 Estimate	2012/2013 Estimate
San Miguel	450	15	557
Santa Rosa	1780	15	894
Santa Cruz	1465	55	1354
Santa Catalina	1342	103	1852
San Clemente	1003	535	1000
San Nicolas	520	452	341

As of March 5, 2004, the Santa Cruz Island Fox was listed as an endangered species (U.S. Fish and Wildlife Service) after the fox population fell from 1,500 individuals to less than 100 within a span of a decade - a 95% reduction rate!

Though the Santa Cruz Island Fox has been historically known for being the top predator on the island for thousands of years, many parts of the evil quartet have caused the species to become one of the animals preyed on instead, causing the species to become close to extinction. The main threat that has endangered the Santa Cruz Island Fox ( as well as other fox species on nearby islands) is the predation by Golden Eagles, When feral goats, sheep, and pigs were introduced to the islands by humans, many Golden Eagles migrated to the islands as well, as they were an attractive food source for the eagles. In addition to preying on the animals, the eagles preyed on the foxes as well, and as a result, the foxes drastically decreased in population size, as they were naive to aerial attacks. Another reason for the decline of island foxes was the transmission of a highly contagious canine distemper virus, a virus that attacks the respiratory, urogenital, gastrointestinal, and nervous systems. Because population was small, there was low genetic diversity, causing the disease to spread rapidly.

Many steps have been taken in use of the Recovery Plan for the Santa Cruz Island Fox. In 2004, around 37 golden eagles had been removed from Santa Cruz Island. Though there are still a few left, there is an ongoing effort to remove all of these eagles. In addition to getting rid of Golden Eagles, there has been successful restoration projects of Bald Eagles to the Channel Islands. The importance of Bald Eagles is that they provide a deterrent to Golden Eagle Colonization. On Santa Cruz Island alone, 15 Bald Eagles and counting are inhabiting the Island (2004). To also get rid of Golden Eagle colonization, Feral Goats, Pigs, and Sheep were removed from the Channel Islands, also removing the incentive for Golden Eagles to live on these islands. To preserve the species and stabilize its population, there has been captive breeding of the Santa Cruz Island Fox. Also as part of the recovery plan, island foxes on all islands have been vaccinated against CDV and rabies to prevent outbreaks and diseases from spreading.

As for personal action, there really isn't much we can do except support the National Park Service in their effort in preserving this species or donating to their cause. As of now, the recovery plan for Santa Cruz Island Foxes is showing a lot of promise, and their population is many times larger than what the population was a decade ago. Progress of the Island fox population can be checked on this link here. Please continue to spread awareness and give support to these cute little island foxes!

Sources: 

"Distemper in Dogs." Distemper in Dogs. N.p., n.d. Web. 23 Nov. 2015.

Draft Recovery Plan for Four Subspecies of Island Fox (Urocyon Littoralis). N.p.: n.p., n.d. Web.

"Friends of the Island Fox: About Island Fox." Friends of the Island Fox: About Island Fox. N.p., n.d. Web. 23 Nov. 2015.

"Index 2015." The Pennsylvania Magazine of History and Biography 139.3 (2015): 373-97. Web.

"Santa Cruz Island Fox." Santa Cruz Island Fox. N.p., n.d. Web. 23 Nov. 2015.

"Support the." Urocyon Littoralis (California Channel Island Fox, Channel Islands Fox, Island Fox, Island Gray Fox, Island Grey Fox). N.p., n.d. Web. 23 Nov. 2015.

United States. National Park Service. "Island Fox." National Parks Service. U.S. Department of the Interior, 22 Nov. 2015. Web. 23 Nov. 2015.