Darwin's fox or Darwin's zorro (Lycalopex fulvipes) is an endangered canid from the genus Lycalopex, which is distantly related to wolves and whose members are not true foxes. It is also known as the zorro chilote or zorro de Darwin It is a small, dark-colored species that is distinguished from other Lycalopex by its shorter legs, broader head, and darker pelage.
Darwin's fox was first collected from San Pedro Island off the coast of Chile by the naturalist Charles Darwin in 1834, after whom the species is named. It was long held that Darwin's fox was a subspecies of the South American gray fox (Lycalopex griseus); however, in 1990, a small population of Darwin's fox was discovered on the mainland in Nahuelbuta National Park and subsequent genetic analysis confirmed that the fox is a distinct species.
The species is thought to number under 1,000 mature individuals, with most found on Chiloé Island and smaller populations on the mainland.
The species is restricted to forest habitats and does not interbreed with the other Lycalopex species. It is smaller and darker-colored than other members of the genus and shows several distinguishing morphological traits. In 1839, Darwin reported in his Journal and Remarks that this specimen was mounted in the Museum of Zoological Society (Zoological Society of London). He described Darwin’s fox as an undescribed species that was more curious but less wise than other foxes, indicating that it was distinct from species that occur on the mainland.
Darwin’s fox was originally given the name Vulpes fulvipes by William Charles Linnaeus Martin in 1837. In 1943, there was some disagreement on if the Darwin's Fox was a subspecies of South American gray fox (at the time Dusicyon griseus, now Lycalopex griseus). Ultimately, Wilfred H. Osgood's morphological observations along with the fact that Darwin's fox populations were isolated from mainland foxes contributed its classification as a separate species, Dusicyon fulvipes.
Scat analysis of Darwin's fox populations in Nahuelbuta National Park consisted mostly of mammals, including Akodon, Monito del monte, Southern big-eared mouse, and long-clawed mole mouse, although it also contained birds, reptiles, insects, arachnids, and plants. Scat analysis of populations on Chiloé Island consisted mostly of invertebrates, especially arthropods and Cratomelus armatus, rodents, and fruits, but also contained fish, reptiles, birds, and Monito del monte. Intake of specific dietary items varies seasonably in this population, with a greater intake of rodents and lesser intake of invertebrates in winter. Current evidence suggests that human perturbation has a negative effect on Darwin’s foxes. On Chiloé Island, Darwin’s foxes were detected less often in areas with lower forest cover or higher dog activity. 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. The population was once considered as Critically Endangered because its main population occurred in one island and their habitat was declining due to human impact. However, a 2016 IUCN assessment estimated a minimum of 412 mature individuals on Chiloé Island and 227 mature individuals in mainland areas, for a total of approximately 639 mature individuals, updating its status as Endangered.
Habitat Loss and Protected Habitats
The loss of habitat is an important threat as Darwin's fox prefers to inhabit forested areas, although they have been sited on plantations as well. The highest rates of forest loss are recorded in the coastal range of the Araucanía Region, where the annual forest loss rate reached 4.8% between 1999-2008. This was the second highest forest loss rate reported for Chilean temperate forest. Consequently, habitat loss reduces the total area available for Darwin’s fox and may favour fox species that prefer open areas. However, the effects of land cover changes on local interaction webs are unknown.
Darwin’s fox has been recorded in the following public protected areas: Alerce Costero National Park (Los Ríos Administrative Region), Nahuelbuta National Park (Araucanía Administrative Region), and Chiloé National Park (Los Lagos Administrative Region). It has also been recorded in the following private protected areas: Caramávida Reserve (Biobío Administrative Region), Oncol Park and Valdivian Coastal Reserve (Los Ríos Administrative Region), and Tantauco, Ahuenco and Tepuhueico Parks (Los Lagos Administrative Region).. In addition, there have been documented cases of foxes being caught in traps and relocated after poultry predation. In Oncol Park, Alerce Costero National Park, and Valdivian Coastal Reserve, there have been reports of some species of foxes being killed as a response to predation on poultry, however, it is unknown if Darwin's fox is part of this population. In September 2023, a Plan for the Recovery, Conservation and Management (Spanish acronym RECOGE) for Darwin's fox was submitted to the Chilean Ministry of Environment with its focus being addressing major knowledge gaps to better implement conservation efforts for the species. In 2025, the Darwin's fox was added to the RECOGE plan, allowing greater protections for the species and its habitats.
Conservation using Molecular Technology
Future conservation efforts for Darwin's fox is expected to integrate genomic technologies with traditional conservation strategies. High-throughput sequencing (HTS) has been proposed as a method to address the knowledge gap on remaining genetic diversity and pathogen exposure of Darwin's fox. Some believe that this molecular data will be essential for developing effective conservation management plans. However, in South America, the application of HTS in conservation research is limited, mainly due to funding shortages, the availability of advanced genomic equipment, and access to analytical expertise. Rural dogs often roam free in Chile and are not provided with any veterinary care. Interactions with these dogs is thought to lead to pathogen transmission. A 2022 study determined dietary overlap in rural dogs and Darwin's foxes despite differences in habitat use by analyzing carbon and nitrogen isotopes in hair samples, concluding shared food resources in human-modified landscapes can be detrimental to the Darwin's fox due to pathogen spillover. Viruses canine distemper and rabies are believed to be able to spread to Darwin's foxes from rural dogs, however, there is little evidence of either disease being present in Darwin's fox populations. Due to the lack of intraspecies interaction, Darwin's fox has limited pathogen spillover from members of its own species but also limited acquired immunity. Because of this, some researchers believe they may be particularly vulnerable to epidemics.
There is also evidence of Toxoplasma gondii and Leptospira in Darwin's fox populations which may pose a threat to the species. Specifically, T. gondii was widespread in Darwin's fox populations that were living in non-anthropized areas. T. gondii exposure in Darwin's fox has no correlation with specific risk factors such as sex, age, season, or degree of anthropization. Darwin's foxes were reported to have one of the highest prevalence of T. gondii antibodies in Chilean wildlife and foxes worldwide, potentially a sign of frequent infections.