Charles Darwin collected the first specimen in 1834. He wrote, “he was so intently absorbed in watching the work of the officers, that I was able, by quietly walking up behind, to knock him on the head with my geological hammer” (Darwin, 1962, p. 281).
Lycalopex fulvipes was originally placed in the genus Vulpes by Martin in 1837. It was also placed in the genus Dusicyon. Until the discovery of the continental population, Darwin’s foxes were considered an island population of South American gray foxes (Pseudalopex griseus). Further study of the continental population revealed that Darwin's foxes lived in sympatry with South American gray foxes, leading to the elevation of Darwin’s foxes to its own species. A study based on mtDNA supported the separation from South American gray foxes (Yahnke, et al. 1996). The results also suggested that current populations are descended from a population that had a broad range in southern Chile before the split of Chiloe Island from the mainland in the late Pleistocene. It is thought that degradation of forest habitats has slowly limited the distribution of these foxes. A study by C. Vila et al. (2004) attempted to assess the possibility of other small populations in the forest areas between Naheulbuta National Park and Chiloe Island but no conclusive evidence was found to support this.
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
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
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
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
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
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 )
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
Several individuals monitored in ongoing research have estimated ages up to seven years.
Range lifespan
Status: wild: 7 (high) years.
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
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.
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)
Darwin's fox or Darwin's zorro (Lycalopex fulvipes) is an endangered canid from the genus Lycalopex. It is also known as the zorro chilote or zorro de Darwin[2] in Spanish and lives on Nahuelbuta National Park, the Cordillera de Oncol, Cordillera Pelada in mainland Chile and Chiloé Island.[4] This small, dark canine weighs 1.8 to 3.95 kg (4.0 to 8.7 lb), has a head-and-body length of 48 to 59 cm (19 to 23 in) and a tail that is 17.5 to 25.5 cm (7 to 10 in).[5] Darwin's fox displays no key differences between male and female other than the fact that the male has a broader muzzle.[6] Males display no territorial behavior and aren't aggressive towards other males roaming around their territory.[6]
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[7] and subsequent genetic analysis has clarified the fox's status as a unique species.[8] 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.[4]
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 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".[9] 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",[10] 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.[11] 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, berries, and seeds.[12] 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.[2] They only occur in areas of primary forest on Chiloé and on the mainland. They are most active at twilight and before sunrise. In contrast to other Lycalopex species, Darwin's fox prefers open spaces. 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.[13] The population was considered as critically endangered because its main population occurred in one island and their habitat was declining due to human impact.[14]
The species was previously classified as Critically Endangered by the IUCN, but in 2016 was downlisted to Endangered, as its area occurrences is apparently substantially larger than originally believed. Current estimates of the total population are still low, with an estimated minimum 227 individuals on the mainland and 412 on Chiloé Island. 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.[2]
The species is often plagued by Mycoplasma haemocanis. The already endangered fox is prone to this infection because the infection's bacteria attach themselves to surface red blood cells of many mammals, and although the species is believed to be no major threat to human life it can spread to humans, dogs, cats, and other wildlife species. The bacteria also seem to spike when located close to any major habitat inhabited by humans as well as where there is a large population of wild dogs present near the species. Researchers are testing RNA subunits of RNase P gene and out of 10 foxes, nine were infected. Even though they are considered "sick", they have no external symptoms (Cabello, 2013). Studies show that many foxes risk of catching the deadly bacteria inclines as they age leaving many older foxes vulnerable. Although the disease is prevalent in this species, little to nothing is known about this disease.[15]
Darwin's fox or Darwin's zorro (Lycalopex fulvipes) is an endangered canid from the genus Lycalopex. It is also known as the zorro chilote or zorro de Darwin in Spanish and lives on Nahuelbuta National Park, the Cordillera de Oncol, Cordillera Pelada in mainland Chile and Chiloé Island. This small, dark canine weighs 1.8 to 3.95 kg (4.0 to 8.7 lb), has a head-and-body length of 48 to 59 cm (19 to 23 in) and a tail that is 17.5 to 25.5 cm (7 to 10 in). Darwin's fox displays no key differences between male and female other than the fact that the male has a broader muzzle. Males display no territorial behavior and aren't aggressive towards other males roaming around their territory.
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.
