Arctic Fox Research Articles

Phase‐dependent red fox expansion into the tundra: implications for management

AbstractExpansion of boreal species into tundra ecosystems is a consequence of climate change and human exploitation that threatens local species through increased predation, competition, and pathogen transmission. Under these circumstances, efficient control of expanding boreal species may be necessary, but the efficiency of such action depends on understanding the ecological influences of expansion. The red fox (Vulpes vulpes) is expanding into the tundra across the Arctic. In Scandinavia, red foxes threaten local tundra species and communities including the endangered Arctic fox (V. lagopus). The ecological dynamics in the tundra are influenced by small rodent cycles (classified into different phases based on seasonal abundance fluctuations), which can affect red fox expansion, distribution, and abundance. We used a 17‐year (2004–2020) dataset from the tundra in Sweden, consisting of raw snow track data, to test how cyclic prey influenced red fox distribution and abundance, and subsequently red fox control. The winter abundance of red fox was influenced by small rodent phase, with higher abundance during high prey availability (i.e., increased number of prey numbers) with no support for a time lag between red fox and small rodent abundance. This suggests that high prey availability attracts red foxes to the tundra and that higher immigration from the boreal zone can be expected in response to increased prey abundances. There was no relationship between red fox control and small rodent availability, but control was influenced by red fox abundance during the previous year, which highlights an opportunistic control strategy. We recommend an adaptive management strategy where authorities include small rodent dynamics in the planning and execution of red fox control.

Use of stable isotopes to reveal trophic relationships and transmission of a food-borne pathogen

Predators in food webs are valuable sentinel species for zoonotic and multi-host pathogens such as Toxoplasma gondii. This protozoan parasite is ubiquitous in warm-blooded vertebrates, and can have serious adverse effects in immunocompromised hosts and foetuses. In northern ecosystems, T. gondii is disproportionately prevalent in Inuit people and wildlife, in part due to multiple routes of transmission. We combined data on T. gondii infection in foxes from Nunavik (northern Québec, Canada) with stable isotope data tracking trophic relationships between foxes and several of their main prey species. Red (Vulpes vulpes) and Arctic fox (Vulpes lagopus) carcasses were collected by local trappers from 2015 to 2019. We used magnetic capture PCR to detect DNA of T. gondii in heart and brain tissues, and enzyme-linked immunosorbent assay to detect antibodies in blood. By linking infection status with diet composition, we showed that infected foxes had a higher probability of consuming aquatic prey and migratory geese, suggesting that these may be important sources of T. gondii transmission in the Arctic. This use of stable isotopes to reveal parasite transmission pathways can be applied more broadly to other foodborne pathogens, and provides evidence to assess and mitigate potential human and animal health risks associated with T. gondii in northern ecosystems.

Canid competition for Arctic fox dens on the tundra

Canid competition for Arctic fox dens on the tundra

Impact of spatial and temporal resource distribution on rabies dynamics in the Arctic

In the Arctic, rabies is endemic in the Arctic fox (Vulpes lagopus), posing a significant and ongoing health risk for people and domestic animals. The mechanisms by which rabies is maintained within the low-density fox populations in the Arctic remain unclear. In this study, we developed a spatially explicit individual-based stochastic epidemiological model and performed an uncertainty analysis to better understand Arctic fox rabies dynamics. Rabies persisted in 25.68% of model simulations, with several variables having significant impact on rabies persistence: probability of rabies transmission, spatial and temporal distribution food resources, mean litter size and variability of rabies incubation periods. Where rabies is endemic, we identified 5 key parameters for rabies dynamics: spatiotemporal resource distribution, probability of birth for adult females, mean and standard deviation of litter size, and incubation period of rabies. Our study demonstrates that Arctic rabies can persist in its primary host under conditions consistent with existing empirical data in the literature and showed the important role played by the spatial and temporal distribution of resources. Finally, our results suggest that the ecological impacts of rapid climate warming could decrease the overall persistence of rabies in the Arctic and the associated health risk in Arctic communities.

Chukotka as a Portal for the Rabies Introduction into Kamchatka (Systematic Review)

The aim of this review was to assess the peculiarities of distribution and epidemiological risk of rabies in the extreme northeast of Asia. The systematic review was prepared through synthesizing publications on rabies over 1860–2022 (n=22) and previously unpublished data for 2009–2023. From the late 19th century until the 1980s, rabies epizootics were consistently observed in Chukotka and Kamchatka. A correlation was found between the time of occurrence of rabies in those territories with a lag period of 1–2 years (r=0.349; p=0.054). In 2009–2023, 24 animal rabies cases were confirmed in Chukotka; rabies has not been registered in Kamchatka since 1981. Until 1982, 5 confirmed human rabies cases were described in Chukotka, as well as 4 lethal cases presumably due to rabies (Chukotka – 3, Kamchatka – 1). The similarity of the spatial distribution of epizootics in different periods of time was established. Rabies was detected mainly in the area of the permanent polar fox (Vulpes lagopus) habitation, in the coastal tundra from the mouth of the Kolyma River to the Anadyr Gulf. Outside this territory (the valleys of the Anadyr and Penzhina Rivers, the Kamchatka Peninsula), rabies was reported in red foxes (Vulpes vulpes). At present, the importance of the polar fox in the spread of rabies in Chukotka has decreased, while the significance of the red fox has increased substantially. Due to vaccination, rabies among dogs is recorded sporadically. Rabies virus isolates from Chukotka belong to the Arctic genetic lineage (Arctic-3 group), which has a circumpolar distribution. The possibility of independent circulation of the rabies virus in the Kamchatka Peninsula is doubtful because of the limited size of the red fox population. Based on the mapping, possible directions for the introduction of rabies to Kamchatka from Chukotka have been identified. Barrier oral rabies vaccination of foxes is recommended during the years of high abundance of red and polar foxes in Chukotka.

Garbage consumption by Arctic terrestrial predators in one of the most pristine land areas on Earth

Garbage may cause substantial environmental perturbations, in part because of its consumption by wildlife. Such consumption may have direct health implications for animals and may also influence trophic relationships. Even in pristine Arctic ecosystems, wildlife feeding in marine environments consume garbage in the form of plastic debris transported by ocean currents. We show that Arctic wildlife in pristine terrestrial environments may also ingest garbage or food items derived from abandoned camp sites. We found the remains of a chocolate wrapper and a milk powder bag in two Arctic fox (Vulpes lagopus) scats and a piece of cloth in an Arctic wolf (Canis lupus arctos) scat collected near Nares Strait, northern Greenland, one of the most pristine terrestrial wilderness regions on Earth. Found on Washington Land and associated with long-abandoned camp sites, these three scats were among 657 Arctic fox scats and 92 wolf scats collected as part of a larger study. Our study demonstrates that these two highly opportunistic predators managed to consume garbage despite the almost complete lack of human activity in this High-Arctic region. Our results highlight that abandoned anthropogenic material in the High Arctic may function as a source of garbage for local terrestrial wildlife over extended time periods, and that garbage consumption may become a potential issue if human activity in remote Arctic regions increases.

РАСПРОСТРАНЕННОСТЬ ЦЕСТОД-ДИФИЛЛОБОТРИИД (PSEUDOPHYLLIDEA:DIPHYLLOBOTHRIIDAE) НА ТЕРРИТОРИИ НАЦИОНАЛЬНОГО ПАРКА «КОМАНДОРСКИЕ ОСТРОВА»

Based on studies (2016-2022) of diphyllobothriasis infestation of animals in the territory of the Commander Islands National Park, it was revealed that the average extent of Bering Arctic Fox invasion was 37.3%, with seasonal fluctuations: winter – 42.7%, spring – 36.6%, summer – 34.9% (fecal helminthoscopy, n=351). The American mink is infected with diphyllobothriids with an invasion intensity of 26.5%. Helminthological autopsies (n=11) revealed strobils of Diphyllobothrium spp. - 5-15 specimens, 20-70 cm long, in 5 Bering Arctic foxes. At the autopsy of 10 individuals of the American mink and 1 individual of the Mednovsky Arctic fox, no diphyllobothriids were found, as well as during helminthoscopic examination of the feces of the Mednovsky Arctic fox (n=37). Encapsulated plerocercoids were detected in the spawning individuals of Oncorhynchus gorbusha from the territory of Bering Island. Key words: National Park "Commander Islands", diphyllobothriids, prevalence, Bering Arctic fox, Mednovsky Arctic fox, American mink.

Collaring nature: The use of foxes to find and rescue the members of the lost Franklin expedition

Abstract The mysterious disappearance of HMS Erebus and HMS Terror while searching for the Northwest Passage under the leadership of Sir John Franklin in the 1840s led to more than thirty different expeditions seeking to find the lost ships and their 129-man crews. It also fostered the first and only use of wild animals as a means of communication in such a rescue operation. Since covering the vast search areas was challenging, if not impossible during sub-freezing winter conditions, some of the would-be rescuers turned to Arctic foxes as couriers of information that they hoped might direct the lost explorers to safety. Based on excerpts from the participants’ diaries and published reports from the period, and on the physical evidence that survives, this paper describes the role Arctic foxes were asked to play in one of the greatest (unsuccessful) rescue efforts ever undertaken in the Far North.

In Search of the Elusive North: Evolutionary History of the Arctic Fox (Vulpes lagopus) in the Palearctic from the Late Pleistocene to the Recent Inferred from Mitogenomic Data.

Despite the high level of interest, the population history of arctic foxes during the Late Pleistocene and Holocene remains poorly understood. Here we aimed to fill gaps in the demographic and colonization history of the arctic fox by analyzing new ancient DNA data from fossil specimens aged from 50 to 1 thousand years from the Northern and Polar Urals, historic DNA from museum specimens from the Novaya Zemlya Archipelago and the Taymyr Peninsula and supplementing these data by previously published sequences of recent and extinct arctic foxes from other regions. This dataset was used for reconstruction of a time-calibrated phylogeny and a temporal haplotype network covering four time intervals: Late Pleistocene (ranging from 30 to 13 thousand years bp), Holocene (ranging from 4 to 1 thousand years bp), historical (approximately 150 years), and modern. Our results revealed that Late Pleistocene specimens showed no genetic similarity to either modern or historical specimens, thus supporting the earlier hypothesis on local extinction rather than habitat tracking.

Geographic Variability of the Shape of the Toothrow in the Arctic Fox (Vulpes lagopus L. 1758): The Role of Asymmetry and Allometry

Geographic Variability of the Shape of the Toothrow in the Arctic Fox (Vulpes lagopus L. 1758): The Role of Asymmetry and Allometry

Effect of Climate Change on Arctic Fox (Vulpes/Alopex Lagopus)

Under the context of climate change, global warming, arctic regions are undergoing a rapid pattern transformation. This paper investigates the link between global warming and arctic fox (Vulpes/Alopex lagopus). This paper focuses on changes in environment. This paper deals briefly on the consequences of climate change and its impacts on various ecosystems in arctic regions. By the in-depth study of the arctic fox traits and compare between regular patterns and features after climate change, it’s clearly to see how much extent the arctic fox is influenced by climate change. This research focus on different characteristics of arctic fox, which are habitat and distribution, coat color change, changes in diet and diseases related to arctic fox cause by climate change. Those are the direct factors that allow people to recognize how climate change is affecting the Arctic fox. This research not only study the direct climate change impacts, as well as the interaction between species. Climate changes in arctic ecosystems alter the ordinary interactions between species in a large extent. The changes in habitats competition and predatory relationships are caused by the species interaction straightforward by the influence of global warming. By analyzing the arctic fox in a broader aspect, people can have a better understanding the challenges that arctic species facing and how arctic fox adapt to new environment successfully. After people become more aware of the severe situation among arctic, they can gain more valuable insights of arctic species adaptations and make effective solution in conservation and protection. Knowing the adaptations of arctic fox is essential for conservation strategies, preservation of arctic biodiversity and maintenance of ecosystem stability.

Predator home range size mediates indirect interactions between prey species in an arctic vertebrate community.

Indirect interactions are widespread among prey species that share a common predator, but the underlying mechanisms driving these interactions are often unclear, and our ability to predict their outcome is limited. Changes in behavioural traits that impact predator space use could be a key proximal mechanism mediating indirect interactions, but there is little empirical evidence of the causes and consequences of such behavioural-numerical response in multispecies systems. Here, we investigate the complex ecological relationships between seven prey species sharing a common predator. We used a path analysis approach on a comprehensive 9-year data set simultaneously tracking predator space use, prey densities and prey mortality rate on key species of a simplified Arctic food web. We show that high availability of a clumped and spatially predictable prey (goose eggs) leads to a twofold reduction in predator (arctic fox) home range size, which increases local predator density and strongly decreases nest survival of an incidental prey (American golden plover). On the contrary, a scattered cyclic prey with potentially lower spatial predictability (lemming) had a weaker effect on fox space use and an overall positive impact on the survival of incidental prey. These contrasting effects underline the importance of studying behavioural responses of predators in multiprey systems and to explicitly integrate behavioural-numerical responses in multispecies predator-prey models.

Long-term responses of Icelandic Arctic foxes to changes in marine and terrestrial ecosystems.

The long-term dynamics of predator populations may be driven by fluctuations in resource availability and reflect ecosystem changes such as those induced by climate change. The Icelandic Arctic fox (Vulpes lagopus) population has known major fluctuations in size since the 1950s. Using stable isotopes analysis of bone collagen over a long-time series (1979-2018), we aimed at identifying the main resources used by Icelandic Arctic foxes during periods of growth and decline to assess if the variations in their population size are linked to fluctuations in the availability of resources. We hypothesized that (1) the decline in Seabird abundance was responsible for the decrease in the fox population; and (2) that the growth in the fox population combined to fluctuations in main resources would lead to an increase in intra-specific competition, ultimately leading to variations in their isotopic niches at the population scale. The isotopic composition of Arctic fox bones differed clearly between inland and coast. Stable isotopes mixing models suggested that marine resources and rock ptarmigans were the most important food source and highlighted a rather stable diet in coastal habitats compared to inland habitats where more fluctuations in dietary composition were observed. Coastal foxes had a broader niche than inland foxes, and there was more variation in niche size in the inland habitat. Our results tend to confirm that a general decline in seabird populations drove the decline in Arctic foxes, especially in coastal habitats. For the inland foxes, our results suggest that the lack of marine resources might have led to an increased use of ptarmigans especially during the most recent period.

Coexistence of two sympatric predators in a transitional ecosystem under constraining environmental conditions: a perspective from space and habitat use

BackgroundRange expansion of species, a major consequence of climate changes, may alter communities substantially due to competition between expanding and native species.MethodsWe first quantified size differences between an expanding habitat generalist, the red fox (Vulpes vulpes), and a circumpolar habitat specialist, the Arctic foxes (Vulpes lagopus), at the edge of the Arctic, where climate-related changes occur rapidly, to predict the likelihood of the larger competitor escalating interference to intraguild killing. We then used satellite telemetry to evaluate competition in a heterogeneous landscape by examining space use early during the foxes' reproductive period, when resource scarcity, increased-food requirements and spatial constraints likely exacerbate the potential for interference. We used time-LoCoH to quantify space and habitat use, and Minta's index to quantify spatio-temporal interactions between neighbors.ResultsOur morphometric comparison involving 236 foxes found that the potential for escalated interference between these species was high due to intermediate size difference. However, our results from 17 collared foxes suggested that expanding and native competitors may coexist when expanding species occur at low densities. Low home-range overlap between neighbors suggested territoriality and substantial exploitation competition for space. No obvious differential use of areas shared by heterospecific neighbors suggested low interference. If anything, intraspecific competition between red foxes may be stronger than interspecific competition. Red and Arctic foxes used habitat differentially, with near-exclusive use of forest patches by red foxes and marine habitats by Arctic foxes.ConclusionHeterogeneous landscapes may relax interspecific competition between expanding and native species, allowing exclusive use of some resources. Furthermore, the scarcity of habitats favored by expanding species may emphasize intraspecific competition between newcomers over interspecific competition, thus creating the potential for self-limitation of expanding populations. Dominant expanding competitors may benefit from interference, but usually lack adaptations to abiotic conditions at their expansion front, favoring rear-edge subordinate species in exploitation competition. However, due to ongoing climate change, systems are usually not at equilibrium. A spread of habitats and resources favorable to expanding species may promote higher densities of antagonistically dominant newcomers, which may lead to extirpation of native species.

Avian influenza overview June-September 2023.

Between 24 June and 1 September 2023, highly pathogenic avian influenza (HPAI) A(H5) outbreaks were reported in domestic (25) and wild (482) birds across 21 countries in Europe. Most of these outbreaks appeared to be clustered along coastlines with only few HPAI virus detections inland. In poultry, all HPAI outbreaks were primary and sporadic with most of them occurring in the United Kingdom. In wild birds, colony-breeding seabirds continued to be most heavily affected, but an increasing number of HPAI virus detections in waterfowl is expected in the coming weeks. The current epidemic in wild birds has already surpassed the one of the previous epidemiological year in terms of total number of HPAI virus detections. As regards mammals, A(H5N1) virus was identified in 26 fur animal farms in Finland. Affected species included American mink, red and Arctic fox, and common raccoon dog. The most likely source of introduction was contact with gulls. Wild mammals continued to be affected worldwide, mostly red foxes and different seal species. Since the last report and as of 28 September 2023, two A(H5N1) clade 2.3.4.4b virus detections in humans have been reported by the United Kingdom, and three human infections with A(H5N6) and two with A(H9N2) were reported from China, respectively. No human infection related to the avian influenza detections in animals on fur farms in Finland or in cats in Poland have been reported, and human infections with avian influenza remain a rare event. The risk of infection with currently circulating avian H5 influenza viruses of clade 2.3.4.4b in Europe remains low for the general population in the EU/EEA. The risk of infection remains low to moderate for occupationally or otherwise exposed people to infected birds or mammals (wild or domesticated); this assessment covers different situations that depend on the level of exposure.

Long-term study of the tundra food web at a hotspot of Arctic biodiversity, the Bylot Island Field Station

We present the history of research activities at the Bylot Island Field Station of the Centre d’études nordiques, a hotspot of biodiversity in the Canadian Arctic. Intensive wildlife studies started at the station in the late 1980s, initially focussing on greater snow goose ecology and its impacts on the tundra vegetation. Since then, studies have expanded to encompass the whole vertebrate food web and have become one of the most comprehensive ecological monitoring programs in the Canadian Arctic. The main vertebrate species monitored include snow geese, lemmings, shorebirds, avian predators, buntings, and Arctic foxes. Over time, we recorded 66 bird and 10 mammal species, including 51 confirmed breeders. Contributions of the program to the field of ecology are numerous, but our demonstration of the dominant role played by predator–prey interactions in the Arctic food web is especially significant for the understanding of direct and indirect trophic interactions. Our studies provided essential information for management decisions taken to control the overabundant greater snow goose population and supported international efforts to assess the state of Arctic biodiversity. Future directions will reflect the need to deepen our understanding of trophic interactions and the effects of climate change using innovative advanced technologies.

Extreme events, trophic chain reactions, and shifts in phenotypic selection

Demographic consequences of rapid environmental change and extreme climatic events (ECEs) can cascade across trophic levels with evolutionary implications that have rarely been explored. Here, we show how an ECE in high Arctic Svalbard triggered a trophic chain reaction, directly or indirectly affecting the demography of both overwintering and migratory vertebrates, ultimately inducing a shift in density-dependent phenotypic selection in migratory geese. A record-breaking rain-on-snow event and ice-locked pastures led to reindeer mass starvation and a population crash, followed by a period of low mortality and population recovery. This caused lagged, long-lasting reductions in reindeer carrion numbers and resultant low abundances of Arctic foxes, a scavenger on reindeer and predator of migratory birds. The associated decrease in Arctic fox predation of goose offspring allowed for a rapid increase in barnacle goose densities. As expected according to r- and K-selection theory, the goose body condition (affecting reproduction and post-fledging survival) maximising Malthusian fitness increased with this shift in population density. Thus, the winter ECE acting on reindeer and their scavenger, the Arctic fox, indirectly selected for higher body condition in migratory geese. This high Arctic study provides rare empirical evidence of links between ECEs, community dynamics and evolution, with implications for our understanding of indirect eco-evolutionary impacts of global change.

Giardia and Cryptosporidium in resident wildlife species in Arctic Alaska

Giardia and Cryptosporidium are zoonotic protozoan parasites that can infect humans and other taxa, including wildlife, often causing gastrointestinal illness. Both have been identified as One Health priorities in the Arctic, where climate change is expected to influence the distribution of many wildlife and zoonotic diseases, but little is known about their prevalence in local wildlife. To help fill information gaps, we collected fecal samples from four wildlife species that occur seasonally on the northern Alaska coastline or in nearshore marine waters—Arctic fox (Vulpes lagopus), polar bear (Ursus maritimus), Pacific walrus (Odobenus rosmarus divergens), and caribou (Rangifer tarandus)—and used immunofluorescence assays to screen for Giardia cysts and Cryptosporidium oocysts. We detected Giardia cysts in 18.3% and Cryptosporidium oocysts in 16.5% of Arctic foxes (n = 109), suggesting that foxes may be potentially important hosts in this region. We also detected Giardia cysts in a single polar bear (12.5%; n = 8), which to our knowledge represents the first such report for this species. Neither parasite was detected in walruses or caribou.

First identification of canine adenovirus 1 in mink and bioinformatics analysis of its 100 K protein.

Animal trade favors the spreading of emerging canine adenovirus 1 (CAdV-1) in mink. Because the 100K protein is not exposed to the viral surface at any stage, it can be used to differentiate the vaccine from wild virus infection. However, no related research has been conducted. This study aimed to find evidence of CAdV-1 in mink and predict the character of the 100K protein in the current circulating CAdV-1 strain of mink. In this experiment, the identification of CAdV-1, the phylogenetic tree, homology, and bioinformatics analysis of 100K were conducted. The results showed that the CAdV-1 was identified in the mink and that its Fiber was located in a separate branch. It was closely related to strains isolated from Norwegian Arctic fox and Red fox. 100K was located in a separate branch, which had the closest genetic relationship with skunks, porcupines, raccoons, and hedgehogs and a far genetic relationship with the strains in dogs. 100K protein is an unstable and hydrophobic protein. It had evidence of selective pressure and recombination, 1 glycosylation site, 48 phosphorylation sites, 60 dominant B cell epitopes, and 9 peptides of MHC-I and MHC-II. Its subcellular localization was mainly in the endoplasmic reticulum and mitochondria. The binding sites of 100K proteins were DBP proteins and 33K proteins. The stains in the mink were different from fox. The exploration of its genomic characteristics will provide us with a deeper understanding of the prevention of canine adenovirus.

Predator-mediated interactions through changes in predator home range size can lead to local prey exclusion.

The strength of indirect biotic interactions is difficult to quantify in the wild and can alter community composition. To investigate whether the presence of a prey species affects the population growth rate of another prey species, we quantified predator-mediated interaction strength using a multi-prey mechanistic model of predation and a population matrix model. Models were parametrized using behavioural, demographic and experimental data from a vertebrate community that includes the arctic fox (Vulpes lagopus), a predator feeding on lemmings and eggs of various species such as sandpipers and geese. We show that the positive effects of the goose colony on sandpiper nesting success (due to reduction of search time for sandpiper nests) were outweighed by the negative effect of an increase in fox density. The fox numerical response was driven by changes in home range size. As a result, the net interaction from the presence of geese was negative and could lead to local exclusion of sandpipers. Our study provides a rare empirically based model that integrates mechanistic multi-species functional responses and behavioural processes underlying the predator numerical response. This is an important step forward in our ability to quantify the consequences of predation for community structure and dynamics.