Wednesday, February 6, 2013

Island Fox

Urocyon littoralis
Meet the Island Fox, one of the smallest foxes in North America, and also one of the most endangered. These small Canines are found exclusively on six of the eight Channel Islands off of the coast of California, and are the only carnivores found only in that state.

Did you know that there are actually six different subspecies of Island Fox? One for each of the six islands that they inhabit? Around 10-16,000 years ago, Grey Foxes from the mainland made their way over the islands. Once there, the population evolved over time to be smaller in size (an example of Insular Dwarfism). They are around 1/3 smaller than their cousins.

The Foxes are incredibly important to the Channel Island habitat because they keep rodent populations down, they keep bird populations stable (by feeding on the small mammals that feed on birds), and they help to disperse the seeds of many native island plants. The foxes are omnivores that hunt during both the day and night, due to the fact that they traditionally has no natural predators.

Unfortunately that is not the case anymore, and Island Foxes have been in trouble for a number of years. About a decade ago some of the subspecies had fewer than 100 individuals left! Disease and the introduction of non-native farm animals and plants have contributed, but the main reason for this rapid decline is the growth of Golden Eagle populations on the islands. Bald Eagles were once the dominant birds-of-prey, and Bald Eagles feed on fish, not Foxes. DDT introduction caused the Bald Eagles to go extinct on the islands, allowing the Golden Eagles to settle in. Golden Eagles, if you couldn't guess, eat Foxes. And they almost ate several of the subspecies into extinction. The San Miguel and Santa Rosa Island Foxes were down to populations of only 15 apiece!

Since 2000, several different conservation efforts have been underway, and the Island Fox populations have been rebounding. Captive breeding programs were quickly established for the remaining Foxes, and their offspring have been re-released to the wild. Golden Eagles have been captured and relocated, and Bald Eagles have be reintroduced. A new report shows that no Foxes have been killed by Golden Eagles in nearly 18 months! Other non-native plants and animals are also being removed or managed more carefully. The species is still Critically Endangered, but the numbers have been on the rise and things are looking promising for the Island Foxes.

IUCN Status : Critically Endangered
Location : Channel Islands
Size : Height up to 12in (30cm), Full length around 2ft(60cm)
Classification : Phylum : Chordata -- Class : Mammalia -- Order : Carnivora
Family : Canidae -- Genus : Urocyon -- Species : U. littoralis

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