'Darwin's Fox' or 'Darwin's Zorro' (''Pseudalopex fulvipes'') is a small
endangered canine from the genus ''
Pseudalopex''. Darwin's Fox was first collected from
Chiloé 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
Grey zorro (''P. griseus''); however, the discovery of a small population of Darwin's Fox on the mainland in
Nahuelbuta National Park in 1990
[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] and subsequent genetic analysis has clarified the fox's status as a unique species.
[Yahnke, C.J. et al. 1996. Darwin's Fox: A Distinct Endangered Species in a Vanishing Habitat. ''Conservation Biology'' 10:366-375]
Taxonomy and evolution
''Pseudaloplex'' is a
South American genus of canine distantly related to wolves and is technically not a
fox. When Charles Darwin collected a specimen from Chiloé Island, he observed that it was distinct from the species, ''P. culpaeus'' and ''P. griseus'', that occur on the mainland
[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.]. Darwin's Fox does not
interbreed with the other ''Pseudalopex'' 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.
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
[Villagrán, C. 1988. Late Quaternary vegetation of Southern Isla Grande de Chiloë, Chile. ''Quaternary Research'' 29: 294–306]. This created two isolated populations of Darwin's Fox.
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 ''P. griseus'' which weighs between 5-10 kg
[Yahnke, C.J. et al. 1996. Darwin's Fox: A Distinct Endangered Species in a Vanishing Habitat. ''Conservation Biology'' 10:366-375].
Ecology
Darwin's fox is generally believed to be a forest obligate species found only in southern temperate
rainforests[Jiménez, J.E., Lucherini, M. & Novaro, A.J. 2004. Pseudalopex fulvipes. In: IUCN 2004. 2004 IUCN Red List of Threatened Species.]. They only occur in forested areas on Chiloé and on the mainland. The are most active at twilight and before sunrise.
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[Jiménez, J.E., Lucherini, M. & Novaro, A.J. 2004. Pseudalopex fulvipes. In: IUCN 2004. 2004 IUCN Red List of Threatened Species.]. 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.
References