Island fox
:
Animalia
:
Chordata
:
mammalia
:
Carnivora
:
Canidae
:
''
:
''littoralis''
Binomial_name
''Urocyon littoralis''
(
Baird,
1857)
The
island fox (''Urocyon littoralis'') is a small
fox that is native to six of the eight
Channel_Islands_of_California. It is the smallest fox species in the
United_States. Other names for the island fox include coast fox, short-tailed fox, island gray fox, Channel Islands fox, Channel Islands gray fox, California Channel Island fox and insular gray fox.
Physical Description
The island gray fox is about a foot high and weighs about three or four pounds. They have gray fur on their backs, a ruddy red coloring on their sides and white fur on their bellies.
Taxonomy and Evolution
The island fox shares the ''
Urocyon'' genus with the mainland
Gray_Fox (''Urocyon cinereoargenteus''), the fox from which it is descended.
There are six subspecies of island fox, each of which is native to a specific Channel Island, and which evolved there independent of the others. The subspecies are ''Urocyon littoralis littoralis'' of
San_Miguel_Island, ''Urocyon littoralis santarosae'' of
Santa_Rosa_Island, ''Urocyon littoralis santacruzae'' of
Santa_Cruz_Island, ''Urocyon littoralis dickeyi'' of
San_Nicolas_Island, ''Urocyon littoralis catalinae'' of
Santa_Catalina_Island and ''Urocyon littoralis clementae'' of
San_Clemente_Island. Foxes from each island are capable of interbreeding, but have genetic and phenotypic distinctions that make them unique, for example, the subspecies have differing numbers of tail vertebrae.
The small size of the island fox is an adaptation to the limited resources available in the island environment. The foxes are believed to have "rafted" to the islands about 15,000 years ago. Initially located on the northern islands, which were probably easier to access during the last
ice_age--when lower sea levels united four of the northernmost islands into a single mega-island and the distance between the islands and the mainland was reduced--it is likely that humans brought the foxes to the southern islands of the archipelago, perhaps as pets or hunting dogs.
Based on genetic distance from their gray fox ancestors, the northern island foxes are probably the older subspecies, while the San Clemente Island foxes have been only resident on their island for about 3,400 years, and the San Nicolas Island foxes established themselves as an independent group about 2,200 years ago. The Santa Catalina Island foxes are the youngest subspecies, having been on their island for about 800 years.
The foxes did not persist on
Anacapa_Island because it has no reliable source of fresh water.
Behavior, Feeding and Habitat
Their preferred habitat is complex layer vegetation with a high density of woody, perennially fruiting shrubs. The foxes live in all of the island
biomes including temperate forest and
rainforest, temperate
grassland and
chaparral. They are not intimidated by humans, as they have historically been at the top of the island
food_chain and had no natural predators. No island supports more than 1,000 foxes. Island foxes eat fruits, insects, birds, eggs, crabs and small mammals, including the
deer_mouse. The foxes tend to move around by themselves, rather than in packs. They are generally
diurnal, albeit with peaks of activity at dawn and dusk.
Island foxes mate for life and are monogamous. Breeding only once a year, a typical island fox litters has one to five kits, which are born in the spring and emerge from the den in early summer. Island fox kits initially have much darker fur than adult foxes. The expected life span of an island fox is about five years.
Endangerment and Recovery Efforts
The island fox was classified as a federally protected
endangered_species in March of 2004, although
IUCN still lists them as "lower risk"
Home |
Index |
mail
Search at Google.Com | Search at MSN.Com
History:
Copyright (c) 2004
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.2
or any later version published by the Free Software Foundation.
A copy of the license is included in the section entitled
"GNU Free Documentation License".