Modelling the spatial population dynamics of arctic foxes: the effects of red foxes and microtine cycles

2009 ◽  
Vol 87 (12) ◽  
pp. 1170-1183 ◽  
Author(s):  
Mark D.F. Shirley ◽  
Bodil Elmhagen ◽  
Peter W.W. Lurz ◽  
Steve P. Rushton ◽  
Anders Angerbjörn
Keyword(s):  
Population Size ◽  
Red Fox ◽  
Negative Impact ◽  
Interference Competition ◽  
Population Trends ◽  
Home Ranges ◽  
Arctic Fox ◽  
Red Foxes ◽  
Microtine Rodents ◽  
Arctic Foxes

The Fennoscandian arctic fox ( Vulpes lagopus (L., 1758)) population is critically endangered, possibly because of increased interference competition from red foxes ( Vulpes vulpes (L., 1758)) and fading cycles in microtine rodents, which cause food shortage. It is not known how these factors drive arctic fox population trends. To test their role in arctic fox decline, we developed a spatially explicit and individual-based model that allowed us to simulate fox interactions and food availability in a real landscape. A sensitivity analysis revealed that simulated arctic fox population size and den occupancy were strongly correlated with fecundity and mortality during the microtine crash phase, but also with red fox status. Model simulations suggested that arctic fox population trends depended on microtine cycles and that arctic fox distributions were restricted by red fox presence. We compared the model predictions with field data collected at Vindelfjällen, Sweden. The model recreated the observed arctic fox trend only with the inclusion of arctic fox avoidance of red fox home ranges. The results indicate that avoidance behaviours can affect population trends and hence that relatively small numbers of red foxes can have a strong negative impact on arctic fox population size and distribution.

Food-niche overlap between arctic and red foxes

2002 ◽  
Vol 80 (7) ◽  
pp. 1274-1285 ◽  
Author(s):  
Bodil Elmhagen ◽  
Magnus Tannerfeldt ◽  
Anders Angerbjörn
Keyword(s):  
Red Fox ◽  
Prey Availability ◽  
Interference Competition ◽  
Niche Overlap ◽  
Alopex Lagopus ◽  
Red Foxes ◽  
Mountain Tundra ◽  
Arctic Foxes ◽  
Food Niches ◽  
Food Niche

Arctic foxes (Alopex lagopus) in Fennoscandia have retreated to higher altitudes on the mountain tundra, possibly because of increased competition with red foxes (Vulpes vulpes) at lower altitudes. In this study we compare summer food niches of the two species in mountain tundra habitat. Arctic foxes consumed lemmings more often than red foxes did, while red foxes consumed field voles and birds more often. Yet despite substantial variation in the diet of each species among summers, food-niche overlaps between the species were consistently high in most summers, as arctic and red foxes responded similarly to temporal changes in prey availability. Occurrences of field voles and birds in fox scats were negatively correlated with altitude, while the occurrences of lemmings tended to increase with altitude. Since arctic foxes bred at higher altitudes than red foxes, the differences between arctic and red fox diets were better explained by altitudinal segregation than by differences between their fundamental food niches. Arctic foxes should therefore endeavour to use the more productive hunting grounds at the lower altitudes of their former range, but interference competition with red foxes might decrease their access to these areas, and consequently cause a decrease in the size of in their realised niche.

scholarly journals AMY2B Gene Copy-Number Variation Studied by Droplet Digital PCR (ddPCR) in Three Canids: Red Fox, Arctic Fox, and Chinese Raccoon Dog

2020 ◽  
Vol 68 (2) ◽  
pp. 51-55
Author(s):  
Michal Antkowiak ◽  
Joanna Nowacka-Woszuk ◽  
Izabela Szczerbal ◽  
Marek Switonski ◽  
Maciej Szydlowski
Keyword(s):  
Copy Number Variation ◽  
Copy Number ◽  
Red Fox ◽  
Digital Pcr ◽  
The Arctic ◽  
Raccoon Dog ◽  
Red Foxes ◽  
Arctic Foxes ◽  
Number Variation ◽  
Raccoon Dogs

Copy-number variation (CNV) is an important source of genetic variation, and one that played a role in the process of domestication. The adaptation to a new diet is a characteristic feature of dog domestication. We therefore sought genomic signatures of this process. The pancreatic alpha-amylase gene (AMY2B), expressed in the pancreas, exhibits a variable number of copies. It has been shown that the multiplication of this gene is associated with the adaptation of dogs to a starch-rich diet. To date, there has been no information made available on the copy-number variation of AMY2B in canid farm animals. The aim of the present study was to examine the AMY2B copy number in the red fox, the arctic fox, and in the Chinese raccoon dog. Droplet digital PCR (ddPCR) was used to count the gene copies in 152 animals (60 red foxes, 53 arctic foxes, and 39 Chinese raccoon dogs). We found that the majority (91%) of the animals had two copies of this gene. Of the red foxes and Chinese raccoon dogs, only 8% had three copies, while 32% of the arctic foxes had three copies. Our study showed that the multiplication of the AMY2B gene did not occur over several decades of breeding selection, which may reflect the low-starch feeding regime.

scholarly journals Size of the lower carnassial in the arctic and the red fox from Late Pleistocene in Belgium compared to other ancient and extant populations

2019 ◽  
Vol 65 (1) ◽  
pp. 127-139 ◽  
Author(s):  
Elwira Szuma ◽  
Mietje Germonpré
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Environmental Conditions ◽  
Red Fox ◽  
The Arctic ◽  
Arctic Fox ◽  
Large Carnivores ◽  
Red Foxes ◽  
Specific Composition ◽  
Food Niche

AbstractLengths, widths, and size proportions (length to width) of the lower carnassial were measured in 45 teeth of the arctic fox and 35 teeth of the red fox from Belgium radiocarbon dated to 46 640–14 120 ka BP. Data the Late Pleistocene foxes from Belgium were compared to 20 ancient and extant populations form Europe, Asia, and North America. The Pleistocene arctic fox from Belgium showed larger carnassial than in all recent samples of this species, whereas the Belgian fossil red foxes were characterized by the carnassial size comparable to that of the recent Siberian red foxes. Both fox species from the Pleistocene of Belgium showed the highest index of the carnassials length to width, which means increase in carnivorous adaptation. We conclude that the higher level of carnivorous specialization reached by the Belgian arctic and red foxes at the end of the Late Pleistocene reflected their scavenging on kills of large carnivores and human hunters (remains of megafauna). Harsh environmental conditions of that period and specific composition of ecosystems led to adapting to a more carnivorous food niche in both foxes.

scholarly journals Relationships between fox populations and rabies virus spread in northern Canada

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246508
Author(s):  
Susan A. Nadin-Davis ◽  
Emilie Falardeau ◽  
Alex Flynn ◽  
Hugh Whitney ◽  
H. Dawn Marshall
Keyword(s):  
Population Structure ◽  
Rabies Virus ◽  
Control Region ◽  
Red Fox ◽  
Population Substructure ◽  
The Arctic ◽  
Red Foxes ◽  
Northern Canada ◽  
Arctic Foxes ◽  
Northern Alaska

Rabies spreads in both Arctic (Vulpes lagopus) and red foxes (Vulpes vulpes) throughout the Canadian Arctic but limited wildlife disease surveillance, due to the extensive landmass of the Canadian north and its small widely scattered human population, undermines our knowledge of disease transmission patterns. This study has explored genetic population structure in both the rabies virus and its fox hosts to better understand factors that impact rabies spread. Phylogenetic analysis of 278 samples of the Arctic lineage of rabies virus recovered over 40 years identified four sub-lineages, A1 to A4. The A1 lineage has been restricted to southern regions of the Canadian province of Ontario. The A2 lineage, which predominates in Siberia, has also spread to northern Alaska while the A4 lineage was recovered from southern Alaska only. The A3 sub-lineage, which was also found in northern Alaska, has been responsible for virtually all cases across northern Canada and Greenland, where it further differentiated into 18 groups which have systematically evolved from a common predecessor since 1975. In areas of Arctic and red fox sympatry, viral groups appear to circulate in both hosts, but both mitochondrial DNA control region sequences and 9-locus microsatellite genotypes revealed contrasting phylogeographic patterns for the two fox species. Among 157 Arctic foxes, 33 mitochondrial control region haplotypes were identified but little genetic structure differentiating localities was detected. Among 162 red foxes, 18 control region haplotypes delineated three groups which discriminated among the Churchill region of Manitoba, northern Quebec and Labrador populations, and the coastal Labrador locality of Cartwright. Microsatellite analyses demonstrated some genetic heterogeneity among sampling localities of Arctic foxes but no obvious pattern, while two or three clusters of red foxes suggested some admixture between the Churchill and Quebec-Labrador regions but uniqueness of the Cartwright group. The limited population structure of Arctic foxes is consistent with the rapid spread of rabies virus subtypes throughout the north, while red fox population substructure suggests that disease spread in this host moves most readily down certain independent corridors such as the northeastern coast of Canada and the central interior. Interestingly the evidence suggests that these red fox populations have limited capacity to maintain the virus over the long term, but they may contribute to viral persistence in areas of red and Arctic fox sympatry.

Den use by arctic foxes (Alopex lagopus) in a subarctic region of western Alaska

1996 ◽  
Vol 74 (4) ◽  
pp. 627-631 ◽  
Author(s):  
R. Michael Anthony
Keyword(s):  
Vulpes Vulpes ◽  
The Arctic ◽  
Arctic Fox ◽  
Alopex Lagopus ◽  
Red Foxes ◽  
Subarctic Region ◽  
Arctic Circle ◽  
Aerial Surveys ◽  
Arctic Foxes ◽  
Den Use

Distribution, abundance, and use of arctic fox dens located in coastal tundra communities of the Yukon–Kuskokwim delta were determined in studies from 1985 to 1990. Dens were denser and less complex than those described in studies conducted above the Arctic Circle. Eighty-three dens of varying complexity were found in the 52-km2 study area. Nineteen dens were used by arctic foxes for whelping or rearing pups. Three females relocated litters to multiple dens; a maximum of four dens were used concurrently by pups from one litter. Although red foxes (Vulpes vulpes) were common in the region, their use of dens in the study area was minimal. Differences in vegetation at den sites and nearby unoccupied sites were minimal. Furthermore, den sites could not be distinguished from non-den sites during aerial surveys.

Coyote – kit fox interactions as revealed by telemetry

1994 ◽  
Vol 72 (10) ◽  
pp. 1831-1836 ◽  
Author(s):  
P. J. White ◽  
Katherine Ralls ◽  
Robert A. Garrott
Keyword(s):  
Home Range ◽  
Predator Avoidance ◽  
Resource Selection ◽  
Prey Species ◽  
Red Fox ◽  
Home Ranges ◽  
Red Foxes ◽  
Kangaroo Rats ◽  
Kit Fox ◽  
Better Than

Red foxes (Vulpes vulpes) avoid areas used extensively by coyotes (Canis latrans), apparently to reduce encounters with coyotes and possible injury or death. It is conceivable that kit foxes (Vulpes macrotis) behave in a similar manner. We used telemetry to examine the spacing patterns and interactions among 24 coyotes and 38 San Joaquin kit foxes (V. m. mutica) in California during a period of declining and low prey abundance (1989–1991). Coyotes showed either territorial (n = 13) or transient (n = 11) spacing patterns, whereas all kit foxes were territorial. Spatially and temporally, coyote home ranges overlapped >30% of each fox home range. Both species used the overlap areas more than expected (P < 0.001), possibly because prey such as kangaroo rats were more abundant in these areas. Fifty-five percent of the areas used extensively by foxes during their nocturnal activities were overlapped by coyote nocturnal-use areas. Concurrently monitored coyotes and foxes that occupied overlapping home ranges (n = 25 combinations) were neither farther apart nor closer together than expected (P = 0.09–0.87), even when the coyote was in the fox's home range. Kit foxes did not avoid coyotes and may be able to coexist with them by exploiting certain prey species better than coyotes and maintaining numerous (≥20) dens throughout their home ranges to facilitate escape. Apparent differences in coyote – red fox and coyote – kit fox relations may be partially attributed to differences in resource selection and predator-avoidance strategies among fox species.

The overabundance of resources leads to small but exclusive home ranges in Arctic fox (Vulpes lagopus) on Bering Island

Polar Biology ◽  
2021 ◽  
Author(s):  
Anton Pletenev ◽  
Elena Kruchenkova ◽  
Yulia Mikhnevich ◽  
Vyacheslav Rozhnov ◽  
Mikhail Goltsman
Keyword(s):  
Home Ranges ◽  
Arctic Fox ◽  
Vulpes Lagopus ◽  
Bering Island

Potential remedy against Echinococcus multilocularis in wild red foxes using baits with anthelmintic distributed around fox breeding dens in Hokkaido, Japan

Parasitology ◽  
2002 ◽  
Vol 125 (2) ◽  
pp. 119-129 ◽  
Author(s):  
H. TSUKADA ◽  
K. HAMAZAKI ◽  
S. GANZORIG ◽  
T. IWAKI ◽  
K. KONNO ◽  
...  
Keyword(s):  
Echinococcus Multilocularis ◽  
Red Fox ◽  
Red Foxes ◽  
Clethrionomys Rufocanus ◽  
Efficient Control ◽  
Positive Rate ◽  
Potential Remedy ◽  
Patent Infection

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

Variation in fur farm and wild populations of the red fox, Vulpes vulpes (Carnivora: Canidae) — Part I: Morphometry

2016 ◽  
Vol 96 (4) ◽  
pp. 589-597 ◽  
Author(s):  
Magdalena Zatoń-Dobrowolska ◽  
Magdalena Moska ◽  
Anna Mucha ◽  
Heliodor Wierzbicki ◽  
Piotr Przysiecki ◽  
...  
Keyword(s):  
Vulpes Vulpes ◽  
Selective Breeding ◽  
Red Fox ◽  
Tail Length ◽  
Morphometric Traits ◽  
Red Foxes ◽  
Ear Height ◽  
Morphological Differences ◽  
The Right ◽  
Almost All

This paper demonstrates the influence of artificial selection on morphometric traits in the red fox [Vulpes vulpes (Linnaeus, 1758)]. Measurements and two proportion coefficients were analysed in 132 wild and 199 farm red foxes. The two groups differed significantly (P ≤ 0.05) on all but one of the measurements. Eight out of 11 measurements were significantly greater in the farm fox population, while only tail length, ear height, and length of the right hind limb were greater in the population of wild foxes. The opposite trend was observed when analysing variation in the measurements — the farm foxes were characterized by a greater variability only in the case of body weight, body length, and breadth of chest. When analysing the sexual dimorphism index in different sex and population groups, in almost all analysed traits, the greatest differences occurred between farm males and wild females. All of the traits examined in this study are important for survival of wild foxes. However, because importance of some traits was reduced during domestication and selective breeding (farm foxes do not have to fight for survival), the genetic relationship between them may have weakened. Other possible causes of morphological differences between the studied groups of red foxes are discussed as well.

scholarly journals Relationship of arctic fox (Alopex lagopus L.) sperm morphology with age of males, sperm concentration, ejaculate volume and acrosin activity

2018 ◽  
Vol 18 (3) ◽  
pp. 741-752 ◽  
Author(s):  
Karolina Stasiak ◽  
Stanisław Kondracki ◽  
Maria Iwanina
Keyword(s):  
Sperm Morphology ◽  
Semen Quality ◽  
Morphological Changes ◽  
Sperm Concentration ◽  
Arctic Fox ◽  
Young Males ◽  
Arctic Foxes ◽  
Relationship Of ◽  
Acrosin Activity ◽  
Sperm Acrosome

Abstract The aim of the study was to determine the relationship of sperm morphology with age of males, ejaculate concentration and volume, as well as with acrosin activity determined in sperm acrosome extracts. The study used manually collected ejaculates from 9 male arctic foxes, including 6 young males aged one year and 3 older males (between 3 and 5 years of age). All of the 39 ejaculates used in the study were classified as normal based on motility exceeding 70%. The ejaculates collected from the foxes were evaluated for volume, sperm concentration and frequency of morphological changes including primary and secondary defects. The spermiograms of the male arctic foxes were classified according to a six-grade subjective scale. In addition, acrosin activity was determined in the sperm acrosome extracts. The data were analysed using the criteria of male age, sperm concentration, ejaculate volume, and acrosin activity. The morphology of arctic fox spermatozoa was dependent on the age of the male. A greater number of morphologically altered spermatozoa tended to occur in the ejaculates of young foxes, which were in their first breeding season. In addition, statistical analysis revealed positive relationships between the frequency of morphological changes in sperm and their ejaculate concentration. In contrast, there were no significant correlations between the percentages of morphologically changed spermatozoa and the ejaculate volume and the content of acrosin, which is an indicator of acrosomal integrity. Semen quality is dependent on the number of sperm in ejaculate with morphological defects which prevent oocyte fertilization. Therefore, morphological assessment of semen, which covers both the number and type of morphological changes, is highly useful when selecting appropriate males for reproduction.

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