Darwin's foxes, Lycalopex fulvipes, are endemic to Chile and were once thought only to inhabit Chiloe Island, which is located off the southern coast. The island is over 200 km long and about 30 km west of Chile. Darwin’s foxes are found on most of the island, except in areas to the north where the island is populated by humans. In the 1970’s a mainland population was discovered at Nahuelbuta National Park in Chile (Medel et al., 1990). The park is about 600 km north of Chiloe Island.
Biogeographic Regions: neotropical (Native )
Vila et al. (2004) found evidence for what may be a third population at Punta Chanchan, north of Valdivia.
Darwin’s foxes are characterized by their short legs, elongated body, and short and bushy tails. Their pelage is a mixture of black and grey hair with rufescent markings on the ears and along the lower portion of the legs. White or light markings can be found under the chin and along the underbelly. There are no significant data supporting sexual dimorphism. However, in a comparison done by Jimenez (2006), males did have a larger separation between the upper canines leading to the appearance of a broader muzzle. Dental formula is 3/3-1/1-4/4-2/3 = 42 (Jimenez and McMahon, 2004).
The following average measurements are from unpublished data from J. E. Jimenez of Chiloe Island and C. McMahon of Nahuelbuta National Park and Chiloe Island that were provided in their report for the IUCN/SSC Canid Specialist Group (2004):
Head and Body Length: 528 mm Tail Length: 221 mm Hind Foot: 106 mm Ear Length: 260 mm Mass: 2.72 kg
Average mass: 2.72 kg.
Average length: 528 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Darwin’s foxes prefer secondary forest to old growth in areas typical to temperate rainforest vegetation. On Chiloe Island the forest is of Valdivian type. It contains conifer species, a few evergreen species, and fruit-bearing trees. The northern and eastern areas of the island are inhabited by humans and agriculture has had some impact on the landscape. On the west coast of the island, the fox actively uses an evergreen forest habitat fragmented by sand dunes. The mainland population is found in dense forest containing monkey-puzzle trees (Araucaria araucaria) and five species of beech (Jimenez and McMahon, 2004).
In Nahuelbuta National Park elevation ranges from 950 to 1462 meters (Jaksic et al., 1990).
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: forest ; rainforest
Habitat and Ecology
On the Pacific coast of Chiloé, Darwin's Fox lives in a fragmented environment of coastal sand dunes mixed with dense evergreen forest. On the northern part of the island, Darwin's Fox uses a relatively flat, but fragmented landscape of broad-leaf forest and dairy cow pastures. Research on the mainland population supports the notion of the species using primarily dense forest (Jaksic et al. 1990; Jiménez et al. 1990). Capture and telemetry data indicate that animals are found in dense Araucaria-Nothofagus forest, open Nothofagus forest and open pasture with decreasing frequency (McMahon et al. 1999). The forest comprises mainly monkey-puzzle trees (Araucaria araucania) and five species of southern beech (Nothofagus spp.), one of which is non-deciduous.
Darwin’s foxes are omnivorous and opportunistic. Their diet varies seasonally with food availability. Their diet contains a variety of food items including small mammals, birds, reptiles, insects, fruits, and seeds. Data from scat analysis show that insects are the most abundant food item but that small mammals make up the largest amount of biomass in the diet. Although Darwin’s foxes may congregate at the site of a carcass, they are mainly solitary hunters. In areas where South American gray foxes (Lycalopex griseus) are present, Darwin’s foxes are more active at night, when South American gray foxes are less active.
Animal Foods: birds; mammals; amphibians; insects; aquatic crustaceans
Plant Foods: seeds, grains, and nuts; fruit
Primary Diet: omnivore
The diet of Darwin's foxes includes a large portion of seeds. It has been suggested that these foxes may be seed dispersers for several plant species.
Ecosystem Impact: disperses seeds
Possible predators of the mainland population of Darwin foxes are pumas (Puma concolor). Large raptors may also prey on these foxes, especially young foxes. However, predation on Darwin foxes has not been described in the literature.
Life History and Behavior
No information on communication within this species has been published. Like other canids, however, they are likely to use olfactory cues, vocalizations, and postural communication extensively. Canids in general have keen senses of smell, hearing, and touch.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Several individuals monitored in ongoing research have estimated ages up to seven years.
Status: wild: 7 (high) years.
Some evidence suggests that Darwin's foxes are monogamous (Jimenez, 2006). Not much is known about the mating behaviors of this species.
Mating System: monogamous
Breeding season begins in October and pups have been documented leaving the den in December. Based on observations of dens, estimated litter size is 2 to 3 individuals (Jimenez and McMahon, 2004). Weaning takes place in February. Most inferences concerning breeding time come from observations on lactating females caught during trapping of island and mainland populations.
Breeding interval: Darwin's foxes breed once yearly.
Breeding season: Breeding occurs in the austral spring.
Range number of offspring: 2 to 3.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous
Darwin's foxes show biparental care and the offspring share their parent’s home range for an undetermined amount of time. Parents share their ranges with offspring from previous litters but no observations so far suggest that these offspring contribute as helpers.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
Most recent estimates place total population sizes at less than 100 individuals in the mainland population and approximately 500 individuals in the island population (Jimenez and McMahon, 2004). The size of the mainland population has been estimated to be on the rise, possibly due to a decrease in number of South American gray foxes (Lycalopex griseus) in the area (Jaksic et al., 1990). A study done by Jimenez (cited by Jimenez and McMahon, 2004) calculated the ecological density of a coastal population on Chiloe Island to be 0.92 foxes km2. This high density was attributed to the large overlap in the territories of these foxes. Agriculture plays a role in limiting the range of Darwin’s foxes in the island and mainland populations. Deforestation rates are limiting the range of these foxes, especially on the mainland where Nahuelbuta National Park is surrounded by agriculture and degraded habitat. On the island these foxes show little to no fear of humans and reports of foxes getting into houses to search for food are not uncommon. Domestic dogs may also present a problem in spreading disease to fox populations (Jimenez and McMahon, 2004).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: critically endangered
IUCN Red List Assessment
Red List Category
Red List Criteria
Total population size is less than 250 mature individuals with at least 90% of the population occurring in one subpopulation (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. Some foxes even breed in these areas. The presence of dogs in the park may be the greatest conservation threat in the form of potential vectors of disease or direct attack. On Chiloé Island, Chiloé National Park has a sizable fox population; however, foxes also live in the surrounding areas, where substantial forest cover remains. These latter areas are vulnerable and continuously subjected to logging, forest fragmentation, and poaching by locals. In addition, being naive towards people places the foxes at risk when in contact with humans. If current relaxed attitudes continue in Nahuelbuta National Park, Chiloé National Park may be the only long-term safe area for the Darwin's Fox.
- 2004Critically Endangered
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). It appears that Darwin's Foxes are restricted to the park and the native forest surrounding the park (McMahon et al. 1999). This park, only 68.3 km² in size, is a small habitat island of highland forest surrounded by degraded farmlands and plantations of exotic trees (Greer 1966). This population is located about 600 km north of the island population and, to date, no other populations have been found in the remaining forest in between (W.E. Johnson pers. comm.).
Darwin's Fox was reported to be scarce and restricted to the southern end of Chiloé Island (Osgood 1943). The comparison of such older accounts (reporting the scarcity of Darwin's fox), with recent repeated observations, conveys the impression that the Darwin's Fox has increased in abundance, although this might simply be a sampling bias.
The presence of dogs in the park may be the greatest conservation threat in the form of potential vectors of disease or direct attack. There is a common practice to have unleashed dogs both on Chiloé and in Nahuelbuta; these have been caught within foxes' ranges in the forest. Although dogs are prohibited in the national park, visitors are often allowed in with their dogs that are then let loose in the park. There has been one documented account of a visitor's dog attacking a female fox while she was nursing her two pups (E. McMahon, pers. obs.). In addition, local dogs from the surrounding farms are often brought in by their owners in search of their cattle or while gathering Araucaria seeds in the autumn. Park rangers even maintain dogs within the park, and the park administrator's dog killed a guiña in the park. Being relatively naive towards people and their dogs is seen as non-adaptive behaviour in this species' interactions with humans.
The island population appears to be relatively safe by being protected in Chiloé National Park. This 430 km² protected area encompasses most of the still untouched rainforest of the island. Although the park appears to have a sizable fox population, foxes also live in the surrounding areas, where substantial forest cover remains. These latter areas are vulnerable and continuously subjected to logging, forest fragmentation, and poaching by locals. In addition, being naive towards people places the foxes at risk when in contact with humans. If current relaxed attitudes continue in Nahuelbuta National Park, Chiloé National Park may be the only long-term safe area for the Darwin's Fox.
No commercial use. However, captive animals have been kept illegally as pets on Chiloé Island (Jiménez, pers. obs).
Nahuelbuta National Park (IX Administrative Region) protects the mainland population in ca. 68 km²; Chiloé National Park (X Admistrative Region) protects the island population in ca. 430 km².
The Temuco Zoo held a male and a female until their release in October 2000 on Chiloé. No known specimens are kept elsewhere.
Gaps in Knowledge
A high priority would be to conduct intensive searches for other populations between Nahuelbuta and Chiloé. There are many remote pockets that are little explored where isolated populations could still be found.
The behavioural ecology of a forest-specialist or forest-dependent species is of utmost interest. Research topics to be explored include: social behaviour (e.g., tolerance to conspecifics), large home range overlaps, presence of helpers, and small litter sizes. In addition, little is known as concerns population dynamics, dispersal behaviour, and metapopulation structure.
Genetic aspects, including levels of inbreeding and inbreeding depression, and past population bottlenecks, are little known and important for future management.
Impacts of and resilience to human-related disturbances, the effects of free-ranging dogs, the foxes ecological naiveté to people, and forest disappearance and fragmentation are all of interest for fox survival. The impact of habitat loss (through forest conversion) on fox populations is also of interest. At least in Chiloé, habitat disturbance per se seems to play little, if any, role in population dynamics. On the mainland, however, fragmentation might increase risk of predation by other native predators.
Considering the potential disease threat posed by domestic dogs, an investigation into diseases and pathogens (and other allied mortality causes) is crucial.
If Darwin's Fox is so closely related to the Sechuran Fox of southern Peru as the circumstantial evidence suggests, then how did the two species diverge and became separated? These two ranges have been separated by the Atacama Desert for a long time. Exploring this question, in connection with other puzzling biogeographical patterns, could provide evidence to better understand canid speciation and species interactions.
Relevance to Humans and Ecosystems
There are no known adverse effects of the Darwin's foxes on humans. They exhibit a lack of fear for humans in urban areas. On the island they inhabit these foxes have been accused of killing poultry .
No economic importance is proposed for this species. Trapping for fur is not reported. The uniqueness of these foxes may make them an ecotourism attraction.
Positive Impacts: ecotourism
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 in Spanish and lives on Nahuelbuta National Park, (Araucanía Region), the Valdivian Coastal Range (Los Ríos Region) in mainland Chile and Chiloé Island.
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 and subsequent genetic analysis has clarified the fox's status as a unique species. In 2012 and 2013 the presence of the Darwin's fox at Oncol Park, Alerce Costero National Park and the Valdivian Coastal Reserve was confirmed through camera trapping.
Taxonomy and evolution
Pseudalopex 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 in December 1834 during the Beagle survey expedition, he observed that this "fox (of Chiloe, a rare animal) sat on the point & was so absorbed in watching [survey work], that he allowed me to walk behind him & actually kill him with my geological hammer". In the 1839 publication of his Journal and Remarks, Darwin said "This fox, more curious or more scientific, but less wise, than the generality of his brethren, is now mounted in the museum of the Zoological Society." He said it was "an undescribed species", indicating that it was distinct from the species (L. culpaeus and L. griseus) that occur on the mainland. Later, Darwin's fox was classified as a subspecies (Lycalopex griseus fulvipes) of the latter.
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. In 1990 a small population of Darwin's fox was found on the mainland in the forested Nahuelbuta National Park, indicating that the fox was not endemic to the island. According to Yahnke et al., in their 1996 article published in the Journal of the Society for Conservation Biology, analysis of mitochondrial DNA of Darwin's fox and the gray fox showed two patterns, indicating Darwin's fox was a new species, closely related to the Sechuran fox. Also according to Yahnke (1995; et al.1996) the present restricted range is a relic of a much wider former range. Zoologists noted the distinctiveness in the ecological niche, appearance, and behavior of this species. Darwin's fox is differentiated from the gray fox in being darker; having shorter legs; a broader, shorter skull; smaller auditory bullae; a more robust dentition; and a different jaw shape and 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. This created two isolated populations of Darwin's fox.
Darwin's fox has a vast diet. 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. It sometimes eats carrion, but it mostly eats live animals and fruit. This makes it mostly an omnivore, sometimes a scavenger.
Darwin's fox is generally believed to be a forest obligate species found only in southern temperate rainforests. They only occur in areas of primary forest on Chiloé and on the mainland. They are most active at twilight and before sunrise.. The population of Chiloé has 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.
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. Fragmentation of forest adjacent to the national park and on the island is a concern for their conservation, and feral dogs may pose the greatest threat to their survival by spreading disease or directly attacking. Persecution by people who think that the foxes attack domestic fowls, though they pose little threat, is also a potential problem.
|Wikispecies has information related to: Pseudalopex|
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- Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Jiménez et al. (2008). Pseudalopex fulvipes. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 11 May 2006. Database entry includes a lengthy justification of why this species is critically endangered
- Farías, A.A., M.A. Sepúlveda, E.A. Silva-Rodríguez, A. Eguren, D. González, N.I. Jordán, E. Ovando, P. Stowhas. 2014. A new population of Darwin’s fox (Lycalopex fulvipes) in the Valdivian Coastal Range. Revista Chilena de Historia Natural 87:3.
- 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
- Yahnke, C.J. et al. 1996. Darwin's Fox: A Distinct Endangered Species in a Vanishing Habitat. Conservation Biology 10:366-375
- Keynes, R. D. ed. 2001. Charles Darwin's Beagle diary. Cambridge: Cambridge University Press. pp. 272–273
- Darwin, C. R. 1839. Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, Journal and Remarks 1832–1836. London: Henry Colburn. p. 341
- 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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