We have characterized two mutations in the
MC1R gene of the blue variant of the arctic fox (
Alopex lagopus) that both incorporate a novel cysteine residue into the receptor. A family study in farmed ...arctic foxes verified that the dominant expression of the blue color phenotype cosegregates completely with the allele harboring these two mutations. Additionally to the altered pigment synthesis, the blue fox allele suppresses the seasonal change in coat color found in the native arctic fox. Consequently, these findings suggest that the MC1R/agouti regulatory system is involved in the seasonal changes of coat color found in arctic fox.
While population cycles are geographically widespread, it is on arctic tundra that such cycles appear to be most influential for the functioning of the whole ecosystem. We give an overview of tundra ...species that exhibit population cycles and describe what are currently believed to be the causal mechanisms. Population cycles most likely originate from trophic interactions within the plant-based tundra food web, where lemmings, either as prey for carnivores or as consumers of plants, play the key role. The predominance of trophic interaction cycles at northern latitudes is ultimately related to climate, and such cycles should therefore be vulnerable to climate change. Recent evidence indicates that changes have already taken place in the dynamics of some key herbivores and their predators, consistent with the expected impacts of climate change. There is a strong need for large-scale integrated monitoring and research efforts to further document such changes and their ecosystem consequences.
Canine circovirus (CanineCV) is a relatively new viral species, belonging to the family Circoviridae, whose pathogenic role is still uncertain. Since its first description in one domestic dog in 2011 ...from the USA, several reports have been documenting its distribution worldwide. Recently, CanineCV was also detected in wild animals such as wolves, foxes and badgers. In order to investigate the presence and the genetic characteristics of CanineCV in foxes of Arctic and Sub‐Arctic regions, the presence of CanineCV DNA in internal organs (liver and spleen) of 51 arctic foxes (Vulpes lagopus) from Svalbard archipelago and 59 red foxes (Vulpes vulpes) from Northern Norway, sampled from 1996 to 2001 and from 2014 to 2018, respectively, was screened by real‐time PCR. CanineCV was detected in 11/51 arctic foxes and in 10/59 red foxes, backdating the circulation of the virus at least to 1996 in the arctic fox population. The complete genome of 14 identified CanineCV was sequenced and analysed showing an identity higher than 80.8% with the reference strains available to date. According to the species demarcation threshold of 80% genome‐wide nucleotide sequence identity for members of the family Circoviridae provided by International Committee on Taxonomy of Viruses (ICTV), all the CanineCV belong to a single species. Phylogenetic analysis revealed that all the CanineCV were subdivided into five main clusters with one including only CanineCV identified in foxes. Furthermore, CanineCV identified in arctic foxes and red foxes formed two distinct lineages. From these data, we hypothesize that the viral transmission did not occur between the two species of foxes as a consequence of the lack of contact between the two hosts or that the virus acquired mutations in the time elapsed between the samplings.
Ecologists are still puzzled by the diverse population dynamics of herbivorous small mammals that range from high-amplitude, multiannual cycles to stable dynamics. Theory predicts that this diversity ...results from combinations of climatic seasonality, weather stochasticity, and density-dependent food web interactions. The almost ubiquitous 3- to 5-y cycles in boreal and arctic climates may theoretically result from bottom-up (plant-herbivore) and top-down (predator-prey) interactions. Assessing, empirically, the roles of such interactions and how they are influenced by environmental stochasticity has been hampered by food web complexity. Here, we take advantage of a uniquely simple High Arctic food web, which allowed us to analyze the dynamics of a graminivorous vole population not subjected to top-down regulation. This population exhibited high-amplitude, noncyclic fluctuations-partly driven by weather stochasticity. However, the predominant driver of the dynamics was overcompensatory density dependence in winter that caused the population to frequently crash. Model simulations showed that the seasonal pattern of density dependence would yield regular 2-y cycles in the absence of stochasticity. While such short cycles have not yet been observed in mammals, they are theoretically plausible if graminivorous vole populations are deterministically bottom-up regulated. When incorporating weather stochasticity in the model simulations, cyclicity became disrupted and the amplitude was increased-akin to the observed dynamics. Our findings contrast with the 3- to 5-y population cycles that are typical of graminivorous small mammals in more complex food webs, suggesting that top-down regulation is normally an important component of such dynamics.
Eight arctic species, including fish, birds and mammals, from diverse habitats (marine and terrestrial) within the Svalbard Archipelago, Norway, were screened for 14 organophosphorus flame retardant ...(PFR) compounds. Ten PFRs were detected: tris(2-chloroethyl)phosphate (TCEP), tris(2-chloroisopropyl)phosphate (TCIPP), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP), triphenyl phosphate (TPHP); 2-ethylhexyl diphenyl phosphate (EHDPP); tris(2-butoxyethyl)phosphate (TBOEP); tritolyl phosphate (TCrP); triisobutyl phosphate (TIBP); tris(2-ethylhexyl)phosphate (TEHP); and butyl diphenyl phosphate (DPhBP). The greatest number of different PFR compounds, and the highest detection frequency were measured in capelin (Mallotus villotus), and the lowest in Brünnich's guillemot (Uria lomvia). The highest concentrations of ΣPFR, as well as the highest concentration of a single PFR compound, TBOEP, were measured in arctic fox (Vulpes lagopus). The presence of PFR compounds in arctic biota indicates that these compounds can undergo long-range transport and are, to some degree, persistent and bioaccumulated. The potential for biomagnification from fish to higher trophic levels seems to be limited.
•Ten PFR compounds were detected within eight Arctic species from the marine and terrestrial ecosystems of Svalbard, Norway.•Highest number of PFR compounds were found in fish.•The potential for biomagnification above fish seems to be limited.
We monitored concentrations of per- and polyfluoroalkyl substances (PFASs) in relation to climate-associated changes in feeding habits and food availability in polar bears (Ursus maritimus) and ...arctic foxes (Vulpes lagopus) (192 plasma and 113 liver samples, respectively) sampled from Svalbard, Norway, during 1997–2014. PFASs concentrations became greater with increasing dietary trophic level, as bears and foxes consumed more marine as opposed to terrestrial food, and as the availability of sea ice habitat increased. Long-chained perfluoroalkyl carboxylates (PFCAs) in arctic foxes decreased with availability of reindeer carcasses. The ∼9–14% yearly decline of C6–8 perfluoroalkyl sulfonates (PFSAs) following the cease in C6–8 PFSA precursor production in 2001 indicates that the peak exposure was mainly a result of atmospheric transport of the volatile precursors. However, the stable PFSA concentrations since 2009–2010 suggest that Svalbard biota is still exposed to ocean-transported PFSAs. Long-chain ocean-transported PFCAs increased 2–4% per year and the increase in C12–14 PFCAs in polar bears tended to level off since ∼2009. Emerging short-chain PFASs showed no temporal changes. Climate-related changes in feeding habits and food availability moderately affected PFAS trends. Our results indicate that PFAS concentrations in polar bears and arctic foxes are mainly affected by emissions.
Arctic fox (Alopex lagopus) numbers vary greatly, with cyclic fluctuations often associated with fluctuations in microtine rodents. However, in areas where small prey mammals are absent, such as ...Iceland and Svalbard, such cyclic fluctuations are lacking. Annual fluctuations in the density of the arctic fox population on the Brøggerhalvøya peninsula and Kongsfjorden region on Svalbard, Norway, were studied from 1990 to 2001 by using indices of fox abundance. All indices showed similar trends; fox numbers were low in 1990, increased until 1995 whereupon they decreased sharply, before increasing again and levelling off in 2001. Increasing numbers of foxes during the first part of the study paralleled increasing numbers of Svalbard reindeer (Rangifer tarandus platyrhynchus) carcasses in winter and increasing numbers of nesting barnacle geese (Branta leucopsis) in summer. This study shows that the number of arctic foxes varies greatly even in areas without fluctuating microtine rodents.PUBLICATION ABSTRACT
The arctic fox (
Vulpes lagopus
), an apex predator with an omnipresent distribution in the Arctic, is a potential source of intestinal parasites that may endanger people and pet animals such as ...dogs, thus posing a health risk. Non-invasive methods, such as coprology, are often the only option when studying wildlife parasitic fauna. However, the detection and identification of parasites are significantly enhanced when used in combination with methods of molecular biology. Using both approaches, we identified unicellular and multicellular parasites in faeces of arctic foxes and carcasses of sibling voles (
Microtus levis
) in Svalbard, where molecular methods are used for the first time. Six new species were detected in the arctic fox in Svalbard,
Eucoleus aerophilus
,
Uncinaria stenocephala
,
Toxocara canis
,
Trichuris vulpis
,
Eimeria
spp., and
Enterocytozoon bieneusi
, the latter never found in the arctic fox species before. In addition, only one parasite was found in the sibling vole in Svalbard, the
Cryptosporidium alticolis
, which has never been detected in Svalbard before.
The arctic fox (Vulpes lagopus), an apex predator with an omnipresent distribution in the Arctic, is a potential source of intestinal parasites that may endanger people and pet animals such as dogs, ...thus posing a health risk. Non-invasive methods, such as coprology, are often the only option when studying wildlife parasitic fauna. However, the detection and identification of parasites are significantly enhanced when used in combination with methods of molecular biology. Using both approaches, we identified unicellular and multicellular parasites in faeces of arctic foxes and carcasses of sibling voles (Microtus levis) in Svalbard, where molecular methods are used for the first time. Six new species were detected in the arctic fox in Svalbard, Eucoleus aerophilus, Uncinaria stenocephala, Toxocara canis, Trichuris vulpis, Eimeria spp., and Enterocytozoon bieneusi, the latter never found in the arctic fox species before. In addition, only one parasite was found in the sibling vole in Svalbard, the Cryptosporidium alticolis, which has never been detected in Svalbard before.
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