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 Food Niche Overlap of Avian Predators (Falconiformes, Strigiformes) in a Field and Forest Mosaic in Central Poland

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 479
Author(s):  
Jakub Gryz ◽  
Dagny Krauze-Gryz
Keyword(s):  
Diet Composition ◽  
Prey Availability ◽  
Niche Overlap ◽  
Breeding Period ◽  
Central Poland ◽  
Avian Predators ◽  
Forest Mosaic ◽  
Field Rodents ◽  
Food Niches ◽  
Food Niche

Food niche overlap statistics are a common way to show competition for food resources in a group of animals. Niche breadths of various species are very variable and their diet composition changes reflecting prey availability. The aim of this study was to evidence the food niche overlap of the whole assemblage of avian predators (eight raptor and owl species, some of them reaching very high densities) in a field and forest mosaic of central Poland. The diet composition was assessed on the basis of pellet analyses and the identification of prey remains found under the nests in the breeding period. The extent of the niche overlap was calculated using a Pianka formula. The food niche overlap indices ranged from 0.02 to 0.93 (mostly below 0.5). The most separate food niche was that of the white-tailed eagle, who regularly preyed on fish. The highest niche overlap was recorded for the common buzzard and common kestrel, two species preying on field rodents, switching to soricomorphs when the former were scarce. Our results confirmed that the food niches of species coexisting in the same area were considerably separate, which is a result of preying on various prey species or searching for them in different habitats.

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.

Summer food composition and food niche overlap of the raccoon dog, red fox and badger in Finland

Ecography ◽  
1998 ◽  
Vol 21 (5) ◽  
pp. 457-463 ◽  
Author(s):  
Kaarina Kauhala ◽  
Paula Laukkanen ◽  
Inez Rége
Keyword(s):  
Red Fox ◽  
Niche Overlap ◽  
Food Composition ◽  
Raccoon Dog ◽  
Food Niche

Seasonal patterns of prey availability and the foraging behavior of arctic foxes (Alopex lagopus) in a waterfowl nesting area

1991 ◽  
Vol 69 (11) ◽  
pp. 2853-2859 ◽  
Author(s):  
Alice Stickney
Keyword(s):  
Foraging Behavior ◽  
Migratory Birds ◽  
Prey Availability ◽  
Limited Resource ◽  
Seasonal Patterns ◽  
Alopex Lagopus ◽  
Arctic Foxes ◽  
Community Types ◽  
One Year ◽  
Nest Initiation

The foraging behavior of arctic foxes was observed in a waterfowl nesting area on the Yukon–Kuskokwim Delta of Alaska in 1985–1986. Observations were made during peak fox activity from two towers, 3 m high, located in different community types. Data were collected continuously for individual foxes on specific activities, the community in which activities occurred, and the type of food obtained. After migratory birds started nesting in the area, the food potentially available to foxes changed from microtines, old caches, and carrion to include eggs and birds. This change was reflected in the foraging behavior of the foxes as they switched to predation on eggs. After nesting began, the search success rate of foxes increased (from <30% to >50%) and search duration decreased (mean 19.7 s before nest initiation versus mean 9.4 s in mid-incubation) as the rate of food acquisition increased. Over 80% of the eggs taken by foxes were cached rather than eaten immediately, which extended the availability of this temporally limited resource to foxes. Eggs were the primary prey of arctic foxes during the nesting stages in both years, even though microtine populations were high in one year (1985) and low in the other (1986).

Influence of snow depth on prey availability and habitat use by red fox

1988 ◽  
Vol 66 (3) ◽  
pp. 587-592 ◽  
Author(s):  
Margaret A. Halpin ◽  
John A. Bissonette
Keyword(s):  
Habitat Use ◽  
Small Mammals ◽  
Snow Depth ◽  
Red Fox ◽  
Prey Availability ◽  
Habitat Preferences ◽  
Hardwood Forests ◽  
Red Foxes ◽  
Mixed Stands ◽  
Snow Conditions

Habitat use by red fox (Vulpes vulpes) was studied during the winters of 1982 and 1983. A total of 125 km of fox trails in eastern Maine were followed during periods of snow cover to examine the influence of snow conditions on fox habitat selection and prey availability. Red foxes used all available habitats but showed preferences for softwood stands and open areas. Hardwood forests were avoided. During both winters, snow depth was greatest in hardwood and mixed stands where soft, powdery conditions prevailed. Windblown, supportive crusts were found in open barrens. Foxes showed habitat preferences for traveling and hunting. Fox sinking depths were least in all habitats when crust conditions prevailed, and during these periods travel distances were more evenly distributed among habitats. Snow influenced relative prey availability. Hunting activities shifted among habitats for small mammals during most of the second winter, when snow was shallow. Proportions of small mammals in the fox diet decreased as snow accumulated and as crusts formed. When snow was deep, foxes hunted in habitats with softwood regeneration and other dense understories that supported snowshoe hare concentrations.

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 Dietary responses of arctic foxes Alopex lagopus to changing prey availability across an Arctic landscape

2005 ◽  
Vol 11 (2) ◽  
pp. 109-121 ◽  
Author(s):  
Nina E. Eide ◽  
Pål Martin Eid ◽  
Pål Prestrud ◽  
Jon E. Swenson
Keyword(s):  
Prey Availability ◽  
Alopex Lagopus ◽  
Arctic 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.

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