Isatis

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.

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).