Linnaeus had most canid species placed in the genus Canis. Kaup (1829:85) revised that genus and placed the Arctic Fox in Alopex. Other early suggestions included it in Vulpes (Oken 1816:1033), or in Leucocyon (Gray 1869:521). In more recent discussions, the Arctic fox is sometimes placed in Vulpes and sometimes in Alopex (e.g. Corbet 1978, Corbet and Hill 1991). However, the current opinion (Wilson and Reeder 2005, ASM 2024) is to include it in Vulpes. Although both names are still used, the inclusion in the Vulpes genus is supported by genetic data (Geffen et al. 1992, Lindblad-Toh et al. 2005, Perini et al. 2010).

European regional assessment: Least Concern (LC)
EU 27 regional assessment: Endangered (EN)

At the European regional level, the species is assessed as Least Concern with large populations of 10,000 mature individuals, occupying a large area, and populations are generally stable (Angerbjörn and Tannerfeldt 2014). The primary climate change-induced threats are identified as loss of tundra habitats, increased interactions with boreal species, e.g. the Red Fox, and disrupted frequency and amplitude of the Lemming cycles (Sillero-Zubrilo and Angerbjörn 2009).

Within the EU 27 region, the Arctic Fox is found only in the far north of Sweden and Finland. Finland has now (2022 and 2023) a few cases of reported reproduction. These are the first reproductions in Finland since 1996 (Eide et al. 2022). The most recent estimate is for Norway, Finland and Sweden of about 500 animals (Eide et al. 2022). The total number of mature individuals in the EU 27 region (Finland and Sweden only) is below 250. Hence, it is listed as Endangered under criterion D. Arctic Foxes in Fennoscandia are isolated from other populations (Cockerill et al. 2022) and thus should be regarded as a subpopulation (according to global Red List guidelines). Within that subpopulation, there are a number of further isolated subpopulations, of which several consist of less than 50 individuals (Eide et al. 2022). 

For the Kola Peninsula, there is limited information about the Arctic Fox population, but a recent assessment shows that the population is small and isolated (Tirronen et al. 2021). Despite being of Least Concern on a regional level, there may nevertheless be cause for concern in north-western mainland Russia, where population densities apparently are low and have failed to recover despite a decrease in hunting pressure (Ehrich et al. 2017, Terekhina et al. 2021).

Arctic Foxes have a circumpolar distribution (Corbet 1978, Hall 1981, Ginsberg and Macdonald 1990, Norén et al. 2011), occurring in three distinct ecological contexts. In the European context, Arctic Foxes occur in four geographic areas that represent all three ecological conditions – continental tundra in western Siberia (Russia), Arctic islands in Svalbard (Norway) and Iceland, and alpine tundra in Fennoscandia (Norway, Sweden, Finland and the Kola peninsula of Russia). Southern and altitudinal limitations on its global distribution is most probably set by intraguild competition with the larger Red Fox (Hersteinsson and Macdonald 1992, Elmhagen et al. 2017a). The southern limit of the distribution is related to the local tree line. Arctic Foxes are only found in forested areas during long migration events, especially after population peak years. For example, there are several reports from the 19^th century of Arctic Foxes in the very south of Sweden. In Europe, Arctic Foxes occur from sea level to 1,500 m.

At the global scale, Arctic Foxes are found throughout the area of continental tundra that covers the northern coasts of Alaska, Canada and Siberia. They occur on most of the arctic islands in the Canadian High Arctic, Greenland, Iceland, Svalbard, Jan Mayen, Bjørnøya, Novaya Zemlja, Wrangel Island, and the Komandor Islands. Arctic Foxes are native to the northern Bering Sea islands (St. Matthew, Hall, St Lawrence). They were introduced to many isolated islands in the Aleutian chain at the end of the 19th century for the fur industry (Bailey 1992), but have since been eradicated from most of these islands. Arctic Foxes are also observed in the open drift ice. During long migrations on the sea ice, Arctic Foxes have been recorded close to the North Pole (Nansen 1904, Fuglei and Tarroux 2019).

Fennoscandia
Arctic Foxes were once very abundant throughout the alpine tundra habitats of Fennoscandia but were greatly reduced due to over-harvesting in the late 19th and early 20th centuries. Even though the population was legally protected, inter-specific competition with Red Foxes as well as irregular small rodent cycles prevented recovery (Hersteinssonet al. 1989, Angerbjörn et al. 2013). In addition to this, inbreeding depression (Norén et al. 2016, Hasselgren et al. 2021), Golden Eagle predation (Meijer et al. 2013) and disease outbreaks (Wallén et al. submitted) have likely contributed to the low population size. Following intensive conservation actions, the negative trend was reversed and the population went through an increase during the past decades (Angerbjörn et al. 2013).

The most recent estimate (2022) is about 500 animals in Norway and Sweden. Finland has now (2022 and 2023) a few reported cases of reproduction (in 2022) since 1996 (Wallén et al. 2023), with 5-10 foxes reported each year (LAJI.FI 2021). The population on the Kola Peninsula has not been accurately censused and remains largely unknown (Tirronen et al. 2021). Estimates range from c.40 individuals (Angerbjörn et al. 2005), and less than 100 individuals (Tirronen et al. 2021). Genetic research showed that the Arctic Fox in Scandinavia is subdivided into four main subpopulations (Dalén et al. 2006), with smaller stepping stone areas between (Hemphill-Keeling et al. 2020). Dispersal between the subpopulations is low (Dalén et al. 2006, Cockerill et al. 2022), with documented signatures of inbreeding in several sub-populations including the Kola Peninsula (Hasselgren et al. 2021, Cockerill et al. 2022). In a large-scale conservation programme in Fennoscandia, a strong increase in the Arctic Fox population was related to a programme of Red Fox culling (Angerbjörn et al. 2013). However, in Canada, the northern expansion of Red Foxes was more related to human activity and anthropogenic subsidies (Gallant et al. 2020), suggesting a synergistic effect between climate warming and human activity (Elmhagen et al. 2017a). However, because the abundance of the Red Fox is also associated with the Lemming cycle, the intraguild predation exerted on the Arctic Fox is in turn intertwined with the Lemming cycle. It is thus likely that the Red Fox would have difficulties surviving in high Arctic areas without anthropogenic food subsidies. Other Lemming-dependent predators can have a similar relationship with Arctic Foxes. For instance, Choi et al. (2019) suggested that a 90% Arctic Fox juvenile mortality during a Lemming population crash was caused by predation from Golden Eagles. Most of the other Lemming predators in the tundra show strong interspecific aggression towards Arctic Foxes, such as Snowy Owl, Pomarine Skua and Rough-legged Buzzard, but the relationship between these predators has not been studied in detail.

Iceland
Numbers of Arctic Foxes on Iceland have fluctuated as a result of differing management practices. From a low point in the 1970s of around 1,300 individuals, the population reached 8,000 individuals around 2,000 but is now decreasing again (Unnsteinsdottir et al. 2016).

Svalbard
There has been no total census of Arctic Foxes on this archipelago, but the population is known to be numerous and stable. Angerbjörn et al. (2004) estimated the population to be about 2,000-3,000 animals but this has not been confirmed. The Arctic Fox went extinct on the island Bjørnøya (part of the Svalbard archipelago) and on Jan Mayen (an isolated island further south between Svalbard and Iceland). The two populations were severely depleted following early 20th-century extermination efforts (Fuglei et al. 1998). On Bjørnøya the Arctic Fox population has re-established by immigration over sea ice in recent years, and breeding is again documented, while no foxes have been observed on Jan Mayen since before 1998 (E. Fuglei pers. comm. 2007).

European Russia (from the White Sea to Novaya Zemlya)
There are no reliable data about Arctic Fox numbers from this region, although Sillero-Zubiri et al. (2004) estimate that the total Russian population (including eastern Siberia) could potentially be in the order of 200,000-800,000 animals. On islands in the Bering Sea, there are populations at critically low levels and they appear to be declining further (see above).

The global population of Arctic Foxes is in the order of several hundred thousand animals [see Norén and Angerbjörn (2023) for specific details]. In areas where the Arctic Fox depends on Lemmings and voles (e.g., mainland Siberia, Fennoscandia and Canada), the size of the population fluctuates strongly (Macpherson 1969, Angerbjörn et al. 1991). In coastal areas where Arctic Foxes feed at bird cliffs or along shorelines, population density can be considerably higher compared to the Lemming ecotype. The species is common in the tundra areas of Russia, Canada, coastal Alaska, Greenland and Iceland. However, populations are critically low in Fennoscandia, islands in the Bering Sea (Mednyi Island, Russia; Pribilof Islands, Alaska, e.g., St Paul), Mednyi Island (Komandor Islands, Russia) and the Pribilof Islands.

The species is confined to arctic and alpine tundra, above or north of the treeline. The Arctic Fox is an opportunistic predator and scavenger but is heavily dependent on fluctuating rodent populations in most mainland areas. In Fennoscandia, the Norwegian Lemming Lemmus lemmus was the main prey in summer followed by birds and Reindeer (Rangifer tarandus) (Frafjord 1995, Elmhagen et al. 2000, Wilkinson et al. 2022). Changes in fox populations have been observed to follow their main prey in three- to five-year cycles (Angerbjörn et al. 1995, Angerbjörn et al. 1999). The typical response to Lemming peak-years is an increase in both the number of litters and litter size (Tannerfeldt and Angerbjörn 1996, Meijer et al. 2013). Foxes living near ice-free coasts, for example in Iceland, have access to both inland prey and sea birds, seal carcasses, fish and invertebrates connected to the marine environment, leading to relatively stable food availability and a more generalist strategy especially in areas without cyclic rodent populations (Hersteinsson and Macdonald 1996, Dalerum and Angerbjörn 2000, Eide et al. 2005). Arctic Foxes are known to prey on wildfowl (Gauthier et al. 2004) and occasionally kill reindeer calves (Prestrud 1992a).

Mortality rates for Arctic Fox juveniles are high and are closely connected to food resource stability and abundance. In a stable coastal environment, annual juvenile survival is estimated at 26% in Svalbard (Eide et al. 2012) and 30% in Iceland (Hersteinsson 1992). For Lemming of the Lemming ecotype, juvenile survival varies from only 0 - 8% after a Lemming crash, with 75-90% of the mortality occurring during their first six months of life (Meijer et al. 2008); however, juvenile survival can reach 40% during high Lemming densities (Hasselgren et al. 2018). Arctic Fox adult survival is considerably higher and rather independent of the rodent cycle (Chevallier et al. 2020).

Foxes reach sexual maturity at 10 months, and mating typically takes place between March and April. The average lifespan for animals that reach adulthood is approximately three years (Angerbjörn et al. 2004). In more stable coastal environments the average age is higher (Prestrud 1992a, Unsteinsdottir et al. 2016). Arctic Fox life history traits reflect adaptations to differing constraints in resource availability. Arctic Foxes in unstable environments (e.g., habitats dominated by cyclic rodents) have higher litter size but do not reproduce yearly, whereas Arctic Foxes in stable environments (e.g., coastal habitats with bird cliffs), have a smaller litter size, in average about 5 cubs, but reproduce every year (Tannerfeldt and Angerbjörn 1996, Angerbjörn et al. 2004). For Lemming foxes, on the other hand, reproduction mainly occurs during increasing and high Lemming abundance; the average litter size across all regions is 6.6 cubs (Tannerfeldt and Angerbjörn 1998), but can reach up to 19 cubs during years of high Lemming abundance (Angerbjörn et al. 2004). The food abundance during pregnancy can influence the number of juveniles born through embryo resorption or abortion (Angerbjörn et al.1991), or after birth through post-natal mortality. Social organization is also highly influenced by resource availability where home range sizes range from 10 km² in stable coastal habitats up to 150 km² in more fluctuating environments (Angerbjörn et al. 1997, Strand et al. 2000, Eide et al. 2004, Rioux et al. 2017), Bardey 2022). In some parts of Iceland, the density of dens can be more than 10/100km² (Hersteinsson and Macdonald 1982). Even higher densities of den sites have been observed on Mednyi Island with up to 70 active dens per 100 km² (Goltsman et al. 2005) and home ranges of 0.5 km² (Pletenev et al. 2021). Similarly, high density of active dens (70 active dens per 100 km²) have been reported on St. Paul Island (White 1992). Both Mednyi Island and St. Paul Island contains breeding seal rookeries that represent superabundant, highly concentrated food resources. On the New Siberian Islands, the density of dens during a peak Lemming year was 14-29 dens per 100 km² (Angerbjörn et al. 1999). Arctic Foxes tend to be territorial, with a mated pair occupying a common territory (Hersteinsson and Macdonald 1986, Prestrud 1992b, Landa et al. 1998, Tannerfeldt and Angerbjörn 1996, Eide et al. 2004). Additional, but non-reproductive adults may also be present within the territory even though their function as “helpers” may be somewhat limited. In some rare cases, it has been observed that two adult females will reproduce within the same territory (Strand et al. 2000, Angerbjörn et al. 2004, Elmhagen et al. 2014, Erlandsson et al.2022). As a result of these home range sizes and territorial social organisation typical densities can vary from 20 adults per 100 km² to 2-4 per 100 km². Arctic Fox dens are often located in sandbanks or ridges (Dalerum et al. 2002). A den can have more than 150 entrances and can be used across multiple generations (Chesemore 1969, Dalerum et al. 2002). One den can persist for more than 300 years (Macpherson 1969). In coastal areas, dens may be located in screes or bedrock (Angerbjörn et al. 2004). Competition for dens in close connection to rich coastal areas is usually high (Hersteinsson and Macdonald 1992). On the other hand, in areas of super-abundant resource areas, such as seal rookeries or nesting bird cliffs, territoriality may be relaxed (White 1992, Eide et al. 2004). Arctic Foxes can move more than 4000 km (Pamperin 2008, Tarroux et al. 2010, Fuglei and Tarroux 2019), often triggered by resource availability (Norén et al. 2011b). This usually occurs during the first year of life, from early autumn to mid-winter (Tarroux et al. 2010). Adult Arctic Foxes often stay in their territory all the year around but juvenile foxes might go on long walks and dispersal migrations. The most common family unit in Arctic Foxes is a monogamous pair, where one male and one female raise their litter. Males and females share the duties during reproduction with rather similar amounts of guarding, feeding and territorial defence (Elmhagen et al. 2014). Males however take a larger share of the territorial defense which in some areas, such as Iceland, can be quite intensive, using barking concerts and scent marking along the territorial borders. It is important for adult foxes to guard their litters at the den and to give warning calls at approaching predators. If the cubs are left alone, for example during periods of food shortage, juvenile survival will decrease (Erlandsson et al. 2017). Juvenile survival is also closely related to parental effects. Litters of inexperienced parents (i.e., first time breeders) are left alone at the den for a larger proportion of time (Erlandsson et al. 2017) which may expose them to a higher predation risk (Meijer et al. 2011). In a similar way, parents that show a more bold personality will get a higher survival of their offspring during food shortage (Choi et al. 2019), related to a more efficient predator defence.

Whilst currently considered Least Concern globally, the species is likely to be strongly affected by climate change in the future. For the Arctic Fox, the primary threats associated with climate change are loss of tundra habitats due to treeline expansion, increased interactions with boreal species, such as the Red Fox, and disruptions in prey demography, such as decreasing frequency and amplitude of the lemming cycles (Silliero Zubrio and Angerbjörn 2009). Projected climate change would intensify fragmentation of the Fennoscandian mountain plateau even further (Herfindal et al. 2010), and may exclude the Arctic Fox from lower-lying alpine tundra areas. Other potential effects are outbreaks of diseases (e.g. sarcoptic mange) transmitted by expanding Red Foxes (Wallén et al. submitted) and seasonal mismatch in fur moulting (Zimova et al. 2022). For a review of other potential impacts of climate change on Arctic Foxes see Ims and Fuglei (2005).

The most important competitor and predator on Arctic Foxes is the Red Fox (Angerbjörn et al. 2013). Being twice the size of Arctic Foxes, and sharing more generalist food habits, the Red Fox is a successful carnivore in many areas but also in marginal conditions of the tundra, as it has recently been reviewed by Elmhagen et al. (2017a). The Red Fox can kill both adult and juvenile Arctic Foxes, they take over Arctic Fox dens and they outcompete Arctic Foxes from carcasses (Elmhagen et al. 2017a). Red Fox populations have increased and expanded in range throughout the 20th century in all arctic areas, but especially in Fennoscandia (Elmhagen et al. 2017a). They often occupy Arctic Fox dens in the most productive, low-lying areas (Kaikusalo et al. 2000, Tannerfeldt et al. 2002). Red Foxes occupy the same niche and eat the same prey as Arctic Foxes (Elmhagen et al. 2002, Wilkinson et al. 2022). They also kill Arctic Fox cubs and adults (Frafjord et al. 1989, Tannerfeldt et al. 2002), and Arctic Foxes avoid breeding close to Red Foxes (Tannerfeldt et al. 2002). There are multiple records of Red Foxes impacting negatively on Arctic Foxes across the Arctic (Elmhagen et al. 2017a).

In Europe, the threats vary between regions. On Svalbard, Arctic Foxes are trapped, but the extent of this trapping is limited to areas close to settlements, and it is therefore not regarded as a threat (Fuglei et al. 1998). Possible threats include the accumulation of long-distance transported pollutants and climate change, which may influence sea ice conditions in the future. The Arctic Fox on Svalbard (Norway) has higher levels of persistent organic pollutants (POPs) than foxes in other parts of the Arctic (Norheim 1978, Wang-Andersen et al. 1993, Fuglei et al. 2007). The levels are similar to those found in Polar Bears from Svalbard and Greenland (Verreault et al. 2005). Such high concentrations of contaminants may have possible toxic health effects.

In Iceland, the status of the Arctic Fox has changed; historically, they were heavily persecuted because of the belief that they were involved in the predation of livestock. Recent legislation has restricted harvest and the population is stable (Hersteinsson 2006, Unsteinsdotter et al. 2016), although in many areas they are still hunted year-round. Lamb carcasses frequently are found among prey remains at dens resulting in the species being considered a pest. Although individual foxes may indeed prey on lambs, it is more likely that a large proportion of the lambs have been scavenged (Hersteinsson 1996).

In Fennoscandia, Arctic Foxes have fragmented distribution along the peninsula in small subpopulations that are relatively isolated from each other. The alpine mountain tundra habitat is naturally fragmented, which increases population vulnerability, inbreeding levels and reduced genetic variation. Overexploitation due to hunting and trapping was most probably the original threat and the reason behind the dramatic decline of Arctic Foxes in Fennoscandia (Østbye et al. 1978, Hersteinsson et al. 1989, Angerbjörn et al. 1995, Linnell et al. 1999, Kaikusalo et al. 2000). The value of Arctic Fox fur together with high bounties for killing foxes gave motivation for this strong persecution. In 1924, Norwegian trappers could get 25% more than an average year's salary for a peasant for only one skin (Østbye and Pedersen 1990). The establishment of the fox farm industry at the beginning of 1900 may also have contributed to this decline. Live trapping of foxes also continued also after protection. Several different factors are believed to have prevented the population from recovering, despite legal protection.Despite an increase in Arctic Fox numbers in Fennoscandia during the last two decades, the remaining sub-populations are still small and relatively isolated from each other. Therefore the risk for inbreeding depression and loss of genetic variation is high (Norén et al. 2016, Hasselgren et al. 2021, Cockerill et al. 2022).

In the southernmost Swedish subpopulation, inbreeding depression has been recorded through a reduction in both survival and reproduction (Norén et al. 2016, Hasselgren et al. 2021). Also, the northernmost Scandinavian sub-population displays signatures of recent inbreeding (Cockerill et al. 2022). Furthermore, comparison with historical samples collected before the bottleneck demonstrated that 25-50% of the genetic variation has been lost (Nyström et al. 2006, Larsson et al.2019). Hybridization with Arctic Foxes that have escaped from fur farms has also been documented (Norén et al. 2009). Genetic mapping revealed hybridization of genotypes originating from escaped farm foxes (Norén et al. 2005), introducing genetic variants not found in the present population of wild Fennoscandian Arctic Fox (Dalén et al. 2005). Introgression of farm fox genes can cause loss of local adaptations or loss of genetic integrity of the wild population. Even though Arctic Fox farming has decreased over the past decades, the historical level of introgression is still unknown.

Globally, the large populations on the continental tundra of Alaska, Canada and Siberia (except Kola) and the island of Greenland are all harvested by local hunters. The main motivation is for fur, although they are killed around settlements in parts of Greenland to reduce the risk of rabies being spread to sled dogs and humans. There is nothing that indicates that these populations are currently threatened by overharvest.

In Iceland, the species was historically heavily persecuted because of the belief that is was involved in livestock predation. Recent legislation in Iceland has restricted harvest, although in many areas they are still hunted year round. There is no detailed information on the use or trade of this species across the region.

On a global scale, the Arctic Fox is classified as Least Concern and is not included in CITES (Angerbjörn and Tannerfeldt 2014). The species is currently assessed as Endangered in both Sweden (SLU 2020) and Norway (Eldegard et al. 2021), having previously been considered Critically Endangered in both countries. It remains Critically Endangered on the Finland national Red List (Hyvärinen et al. 2019).

Occurrence in protected areas
For Iceland and Svalbard, Arctic Foxes could potentially appear in most areas. Good information is available for Norway, Sweden and Finland.

Norway: The National Parks Blåfjell-Skjækerfjella, Børgefjell, Saltfjellet, Øvre Dividal, Reisa. On Svalbard, Arctic Foxes are found in most protected areas.
Sweden: The National Parks Sarek, Padjelanta, and Stora Sjöfallet, in the county of Norrbotten; the Nature Reserves Vindelfjällen, Marsfjället, and Gitsfjället, in the county of Västerbotten; the Nature Reserves Hamrafjället, Henvålen-Aloppan, Vålådalen, Gråberget-Hotagsfjällen, Frostvikenfjällen, Sösjöfjällen and Skäckerfjällen, in the county of Jämtland.

Finland: Malla, Käsivarren erämaa, Iiton palsasuot, Saanan luonnonsuojelualue, Muotkatunturin erämaa, Hanhijänkä Pierkivaaran jänka, Pieran Marin jänkä, Kevo, Kaldoaivin erämaa, Paistunturin erämaa, Pulmankijärvi.

There appear to be no significant protected areas in the Kola Peninsula that contain Arctic Foxes.

Legislation
Within Europe, the Arctic Fox is appointed a priority species based on Actions by the Community relating to the Environment (ACE) and the Habitats Directive, and is therefore given full protection. It is also included in the Bern Convention (Appendix II - Strictly protected fauna species). However, the species and its dens have had total legal protection in Sweden since 1928, in Norway since 1930, and in Finland since 1940. In Norway, the Arctic Fox is protected following the “Biodiversity Act” (2009) and in Sweden, the Arctic Fox is included in the “Species protection ordinance” (2007). Based on a 2015 agreement between the Swedish and Norwegian governments, the Scandinavian Arctic Fox is subject to a joint management plan both in Sweden and Norway (Elmhagen et al. 2017b).

Following a severe sarcoptic mange outbreak on Mednyi (Goltsman et al. 1996), Arctic Foxes was listed in the Red Book of the Russian SFSR (1983).

Conservation measures taken
A trans-national action plan is developed for Sweden and Norway (Elmhagen et al. 2017b). Since 2018, there is a monitoring programme and report for Sweden and Norway, and since 2022, also Finland is included in the joint report. In Sweden and Finland, a species-specific conservation project has been completed by two EU/LIFE-projects (SEFALO 1998-2002, and SEFALO + 2003-2008), with the latter also involving Norway (Angerbjörn et al. 2013). Furthermore, joint conservation efforts have been implemented under several EU/Interreg programmes (Felles Fjellev 1 and II, Felles Fjellrev Nord I and II). Measures taken include den creation, supplementary feeding, Red Fox control, treatment of sarcoptic mange, as well as building public awareness and education work (Elmhagen et al. 2017b).

Actions are focused on core areas as well as stepping stone areas in order to prevent fragmentation. An evaluation showed strong population increases in areas with intensive supplemental feeding and Red Fox control (Angerbjörn et al. 2013). In Norway, a captive breeding programme was started in 2000, and the first successful captive reproduction and release of foxes happened in 2006 (Landa et al. 2017, 2022). Between 2006-2020, a total of 434 Arctic Foxes, born in captivity, were released in different Norwegian sites (Landa et al. 2022). The releases have facilitated the reestablishment of empty sites, as well as demographic and genetic supplement to existing populations (Landa et al. 2017, 2022; Hemphill-Keeling et al. 2020; Hasselgren et al. 2018). The success has however been context-dependent (Wallén et al. 2022) and sometimes short-lived (Lotsander et al. 2021, Hasselgren et al. 2021).