Darwin's Fox
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| Lycalopex fulvipes Martin, 1837 |
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Darwin's Fox or Darwin's Zorro (Lycalopex fulvipes) is a small Critically endangered canine from the genus Lycalopex. It is also known as the Zorro Chilote or Zorro de Darwin[2] in Spanish and lives on Chiloé Island and Nahuelbuta National Park in mainland Chile (IX Region Araucania).
Darwin's Fox was first collected from San Pedro Island off the coast of Chile by the naturalist Charles Darwin in 1834. It was long held that Darwin's Fox was a subspecies of the South American Gray Fox (L. griseus); however, the discovery of a small population of Darwin's Fox on the mainland in Nahuelbuta National Park in 1990[3] and subsequent genetic analysis has clarified the fox's status as a unique species.[4]
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[edit] Taxonomy and evolution
Lycalopex is a South American genus of canine distantly related to wolves and is technically not a fox. When Charles Darwin collected a specimen from San Pedro Island in Chiloé Archipelago, he observed that it was distinct from the species (Culpeo L. culpaeus and the South American Gray Fox L. griseus) that occur on the mainland.[5] Darwin's Fox does not interbreed with the other Lycalopex species, only lives in forests, and is smaller and darker-colored than the other species. It was not until a small population of Darwin's Fox was found on the mainland in the forested Nahuelbuta National Park and subsequent genetic analysis was performed, that the Darwin's Fox was confirmed as a distinct species.
[edit] Historic of classification
Darwin's Fox firstly was described by Charles Darwin during his travel on Beagle ship. Later, the population of Darwin's Fox that live in Chiloé was distinguish as a subspecies of the Grey Fox (Pseudalopex griseus fulvipes). When in 1990, scientists discovered that a new population exists in Nahuelbuta National Park, there began a discussion for a new taxonomy of "Chiloé" fox, not endemic to this island but living on the continent. According to Yanke et al., in their 1996 article publish in the Journal of the Society for Conservation Biology, shows mitochondrial analysis composed of two patterns (Darwin's Fox and Grey Fox) confirming elements component of nucleosomes and recognized the rare specimens as a new species, closely related to the Sechuran Fox. Also according to Yahnke (1995; et al.1996 ) they are a relic of a former more wider range. Now Darwin's Fox have been classified as distinct, but sympatric species, was a results of workings of divergency in selection and is describe as a sister taxon. Zoologist noticed the difference in this species from their ecological niche, appearance and behavior. Darwin's Fox is differentiated from the Grey Fox in being darker, has shorter legs, a broader, shorter skull, smaller auditory bullae, a more robust dentition and also differs from the Grey Zorro in jaw shape and its style of premolar occlusion.
In the late Pleistocene, Chiloé Island was connected to mainland Chile by a land bridge. The land bridge was severed about 15,000 years ago when the sea level rose following the last glaciation[6]. This created two isolated populations of Darwin's Fox.
[edit] Physical description
Darwin's Fox has a dark brown coat with red areas on its head and face, and it has shorter legs than the mainland foxes, and weighs 2-4 kg, much smaller than the L. griseus which weighs between 5-10 kg[4]. Coat of Darwin's Fox is dark grey-violet with red areas on it ears, head and limbs. Their dewlap and underbelly is mainly white, and thorax is sometimes locally cover of white coating.
[edit] Diet
Darwin's Fox feed on various food. In dense forests, where it exists, the foxes hunt for mammals, reptiles, beetles and invertebrates. Sometimes it selects fruits and berries. Birds and amphibians to a lesser degree are also consumed.
[edit] Ecology
Darwin's fox is generally believed to be a forest obligate species found only in southern temperate rainforests.[2] They only occur in forested areas on Chiloé and on the mainland. They are most active at twilight and before sunrise. Darwin's fox is generally only occur in the southern primary temperate subtropical forests their range - variously from other false foxes (especially Pseudalopex), prefers open spaces. The population of Chiloé is calculate to about 200 individuals, and Nahuelbuta on the mainland contains about 50 individuals. The total population size is about 250 mature individuals with at least 90% of the population occurring in one subspopulation (Chiloé Island). Although the species is protected in Nahuelbuta National Park, substantial mortality sources exist when foxes move to lower, unprotected private areas in search of milder conditions during the winter. [7].
[edit] Conservation status
It is believed that there are only 250 Darwin's foxes on Chiloé Island and up to 70 on the mainland, and they are listed as critically endangered by the World Conservation Union.[2] Fragmentation of forest adjacent to National Parks is a concern for their conservation and dogs in the Parks may be the greatest conservation threat in the form of potential vectors of disease or direct attack.
Threats for populations of Darwin's Fox is devastation unique forest - their habitat, diseases from feral dogs and direct persecution by people, think that foxes attack the fowls.
[edit] References
- ^ Wozencraft, W. C. (16 November 2005). in Wilson, D. E., and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press. ISBN 0-801-88221-4.
- ^ a b c d Jiménez et al (2004). Pseudalopex fulvipes. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes a lengthy justification of why this species is critically endangered
- ^ Medel, R.G. et al. 1990. Discovery of a continental population of the rare Darwin Fox, Dusicyon fulvipes (Martin, 1839) in Chile. Biological Conservation 51:71-77
- ^ a b Yahnke, C.J. et al. 1996. Darwin's Fox: A Distinct Endangered Species in a Vanishing Habitat. Conservation Biology 10:366-375
- ^ Darwin, C. 1839. Journal of researches into the geology and natural history of the various countries visited by H.M.S. Beagle, under the command of Captain Fitzroy, R.N. from 1832–1836. London: Henry Colburn.
- ^ Villagrán, C. 1988. Late Quaternary vegetation of Southern Isla Grande de Chiloë, Chile. Quaternary Research 29: 294–306
- ^ Jiménez, J.E., Lucherini, M. & Novaro, A.J., 2004; IUCN & CSG 2004). On mainland Chile, Jaime Jiménez has observed a small population since 1975 in Nahuelbuta National Park; this population was first reported to science in the early 1990s (Medel et al. 1990; Jiménez, J.E., Lucherini, M. & Novaro, A.J., 2004; IUCN, 2004
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