Annual, seasonal, and habitat-related variation in feeding habits of the arctic fox (Alopex lagopus) on St. Lawrence Island, Bering Sea

Small rodents, especially northern voles (Microtus oeconomus), were the most frequently occurring prey in the stomach contents and scats of arctic foxes collected on St. Lawrence Island between 1955 and 1970. Annual variations in the winter occurrence of voles in the stomach contents correlated well with variations in population density of the voles in the previous summer. However, when the foxes' summer dens were in or near large marine bird colonies, birds predominated in the diet. Even in winter, birds tended to occur more frequently in the diet of foxes trapped on bird cliffs than on the tundra. Since the birds are absent from the cliffs in winter, these evidently were from cached supplies. In terms of biomass, birds were of equal or greater importance than voles in the overall diet, and marine mammal carrion became most important in winter and early spring, when live prey were scarce. Although populations of live prey were abundant and readily accessible in summer, they were absent or inaccessible in winter; hence, even in this area of abundance, storage of food was essential for survival of foxes through the cold months.

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Comparison of Inorganic Chlorine in the Southern Hemispheric lowermost stratosphere during Late Winter 2019

10.5194/acp-2021-356 ◽

2021 ◽

Author(s):

Markus Jesswein ◽

Heiko Bozem ◽

Hans-Christoph Lachnitt ◽

Peter Hoor ◽

Thomas Wagenhäuser ◽

...

Keyword(s):

Degradation Products ◽

Polar Vortex ◽

Boundary Region ◽

Early Spring ◽

Active Chlorine ◽

The Arctic ◽

Late Winter ◽

Annual Variations ◽

The Difference ◽

The Antarctic

Abstract. Inorganic chlorine (Cly) is the sum of the degradation products of long-lived chlorinated source gases. These include the reservoir species (HCl and ClONO2) and active chlorine species (i.e. ClOx). The active chlorine species drive catalytic cycles that deplete ozone in the polar winter stratosphere. This work presents calculations of inorganic chlorine (Cly) derived from chlorinated source gas measurements on board the High Altitude and Long Range Research Aircraft (HALO) during the Southern hemisphere Transport, Dynamic and Chemistry (SouthTRAC) campaign in late winter and early spring 2019. Results are compared to Cly of the Northern Hemisphere derived from measurements of the POLSTRACC-GW-LCYCLE-SALSA (PGS) campaign in the Arctic winter of 2015/2016. A scaled correlation was used for PGS data, since not all source gases were measured. Cly from a scaled correlation was compared to directly determined Cly and agreed well. An air mass classification based on in situ N2O measurements allocates the measurements to the vortex, the vortex boundary region, and mid-latitudes. Although the Antarctic vortex was weakened in 2019 compared to previous years, Cly reached 1687 ± 20 ppt at 385 K, therefore up to around 50 % of total chlorine could be found in inorganic form inside the Antarctic vortex, whereas only 15 % of total chlorine could be found in inorganic form in the southern mid-latitudes. In contrast, only 40 % of total chlorine could be found in inorganic form in the Arctic vortex during PGS and roughly 20 % in the northern mid-latitudes. Differences inside the respective vortex reaches up to 565 ppt more Cly in the Antarctic vortex 2019 than in the Arctic vortex 2016 (at comparable distance to the local tropopause). As far as is known, this is the first comparison of inorganic chlorine within the respective polar vortex. Based on the results of these two campaigns, the difference of Cly inside the respective vortex is significant and larger than reported inter annual variations.

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Digging into the behaviour of an active hunting predator: arctic fox prey caching events revealed by accelerometry

Movement Ecology ◽

10.1186/s40462-021-00295-1 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Jeanne Clermont ◽

Sasha Woodward-Gagné ◽

Dominique Berteaux

Keyword(s):

Foraging Behaviour ◽

Supervised Machine Learning ◽

The Arctic ◽

Arctic Fox ◽

Arctic Foxes ◽

Axial Acceleration ◽

Behavioural Classification ◽

Spatio Temporal ◽

Prey Handling ◽

Bird Colonies

Abstract Background Biologging now allows detailed recording of animal movement, thus informing behavioural ecology in ways unthinkable just a few years ago. In particular, combining GPS and accelerometry allows spatially explicit tracking of various behaviours, including predation events in large terrestrial mammalian predators. Specifically, identification of location clusters resulting from prey handling allows efficient location of killing events. For small predators with short prey handling times, however, identifying predation events through technology remains unresolved. We propose that a promising avenue emerges when specific foraging behaviours generate diagnostic acceleration patterns. One such example is the caching behaviour of the arctic fox (Vulpes lagopus), an active hunting predator strongly relying on food storage when living in proximity to bird colonies. Methods We equipped 16 Arctic foxes from Bylot Island (Nunavut, Canada) with GPS and accelerometers, yielding 23 fox-summers of movement data. Accelerometers recorded tri-axial acceleration at 50 Hz while we obtained a sample of simultaneous video recordings of fox behaviour. Multiple supervised machine learning algorithms were tested to classify accelerometry data into 4 behaviours: motionless, running, walking and digging, the latter being associated with food caching. Finally, we assessed the spatio-temporal concordance of fox digging and greater snow goose (Anser caerulescens antlanticus) nesting, to test the ecological relevance of our behavioural classification in a well-known study system dominated by top-down trophic interactions. Results The random forest model yielded the best behavioural classification, with accuracies for each behaviour over 96%. Overall, arctic foxes spent 49% of the time motionless, 34% running, 9% walking, and 8% digging. The probability of digging increased with goose nest density and this result held during both goose egg incubation and brooding periods. Conclusions Accelerometry combined with GPS allowed us to track across space and time a critical foraging behaviour from a small active hunting predator, informing on spatio-temporal distribution of predation risk in an Arctic vertebrate community. Our study opens new possibilities for assessing the foraging behaviour of terrestrial predators, a key step to disentangle the subtle mechanisms structuring many predator–prey interactions and trophic networks.

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Effect of age and breeding season on sperm acrosin activity in the arctic fox (Alopex lagopus L.)

Polish Journal of Veterinary Sciences ◽

10.2478/pjvs-2014-0025 ◽

2014 ◽

Vol 17 (1) ◽

pp. 177-179 ◽

Cited By ~ 2

Author(s):

K. Stasiak ◽

B. Janicki

Keyword(s):

Breeding Season ◽

The Arctic ◽

Arctic Fox ◽

Alopex Lagopus ◽

A Value ◽

Arctic Foxes ◽

The Mean ◽

One Year ◽

Acrosin Activity ◽

Effect Of Age

Abstract The objective of this study was to determine the effect of age and reproductive season on selected properties of semen from the arctic fox, Alopex lagopus L. The experiment used 40 ejaculates collected manually from 6 animals (3 foxes aged one year and 3 foxes older than three years). Statistically less semen (0.39 cm3) was collected from the young compared to the older animals, and the ejaculates obtained were characterized by higher concentration of spermatozoa (195.04 x 106/cm3). In turn, sperm acrosomal extracts from the older animals contained statistically more acrosin (6,4 mU/106 spermatozoa). In the sperm acrosomal extracts prepared during the first semen sampling, the mean acrosin activity did not exceed 2.3 mU/million spermatozoa. At subsequent semen sampling dates, the activity of the analysed enzyme increased to reach 7.72mU/million spermatozoa. In the extracts obtained from the semen collected at the end of the breeding season of arctic foxes, the acrosin activity again reached a value obtained at the beginning of the season.

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Home-range sizes and altitude selection for arctic foxes and wolverines in an alpine environment

Canadian Journal of Zoology ◽

10.1139/z97-209 ◽

1998 ◽

Vol 76 (3) ◽

pp. 448-457 ◽

Cited By ~ 32

Author(s):

Arild Landa ◽

Olav Strand ◽

John DC Linnell ◽

Terje Skogland

Keyword(s):

The Arctic ◽

Domestic Sheep ◽

Home Ranges ◽

Alopex Lagopus ◽

Conservation Areas ◽

Alpine Environment ◽

South Central ◽

Arctic Foxes ◽

Selection For ◽

Peripheral Areas

We compared the use of space and habitat by wolverines, Gulo gulo, and arctic foxes, Alopex lagopus, on the Snøhetta plateau and surrounding mountains in south-central Norway. The arctic foxes used smaller annual home ranges than the wolverines, whose home ranges were among the largest yet reported for the species. In both species, resident males used larger home ranges than resident females. Arctic foxes used a much narrower, and higher, range of altitudes than wolverines, always above the tree line. Wolverines used lower altitudes in winter than in summer. Female wolverines showed pronounced seasonal peaks in their use of the peripheral areas of their home ranges. Both species showed an ability to cross at least some transportation corridors (road, rail, human settlements) in the area. The habitat available at Snøhetta appears suitable for arctic foxes and does not explain the failure of the population to recover during 67 years of protection. Because of predation on domestic sheep, wolverines will probably be confined to a series of core conservation areas (CCA). At present densities (0.28-0.36 wolverines per 100 km2), the CCA surrounding Snøhetta can contain from 36 to 50 wolverines.

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Comparison of inorganic chlorine in the Antarctic and Arctic lowermost stratosphere by separate late winter aircraft measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-17225-2021 ◽

2021 ◽

Vol 21 (23) ◽

pp. 17225-17241

Author(s):

Markus Jesswein ◽

Heiko Bozem ◽

Hans-Christoph Lachnitt ◽

Peter Hoor ◽

Thomas Wagenhäuser ◽

...

Keyword(s):

Boundary Region ◽

Early Spring ◽

Active Chlorine ◽

The Arctic ◽

Late Winter ◽

Annual Variations ◽

Research Aircraft ◽

Gas Measurements ◽

Catalytic Cycles ◽

The Antarctic

Abstract. Stratospheric inorganic chlorine (Cly) is predominantly released from long-lived chlorinated source gases and, to a small extent, very short-lived chlorinated substances. Cly includes the reservoir species (HCl and ClONO2) and active chlorine species (i.e., ClOx). The active chlorine species drive catalytic cycles that deplete ozone in the polar winter stratosphere. This work presents calculations of inorganic chlorine (Cly) derived from chlorinated source gas measurements on board the High Altitude and Long Range Research Aircraft (HALO) during the Southern Hemisphere Transport, Dynamic and Chemistry (SouthTRAC) campaign in austral late winter and early spring 2019. Results are compared to Cly in the Northern Hemisphere derived from measurements of the POLSTRACC-GW-LCYCLE-SALSA (PGS) campaign in the Arctic winter of 2015/2016. A scaled correlation was used for PGS data, since not all source gases were measured. Using the SouthTRAC data, Cly from a scaled correlation was compared to directly determined Cly and agreed well. An air mass classification based on in situ N2O measurements allocates the measurements to the vortex, the vortex boundary region, and midlatitudes. Although the Antarctic vortex was weakened in 2019 compared to previous years, Cly reached 1687±19 ppt at 385 K; therefore, up to around 50 % of total chlorine was found in inorganic form inside the Antarctic vortex, whereas only 15 % of total chlorine was found in inorganic form in the southern midlatitudes. In contrast, only 40 % of total chlorine was found in inorganic form in the Arctic vortex during PGS, and roughly 20 % was found in inorganic form in the northern midlatitudes. Differences inside the two vortices reach as much as 540 ppt, with more Cly in the Antarctic vortex in 2019 than in the Arctic vortex in 2016 (at comparable distance to the local tropopause). To our knowledge, this is the first comparison of inorganic chlorine within the Antarctic and Arctic polar vortices. Based on the results of these two campaigns, the differences in Cly inside the two vortices are substantial and larger than the inter-annual variations previously reported for the Antarctic.

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Helminths of the arctic fox, Alopex lagopus (L.), in Greenland

Canadian Journal of Zoology ◽

10.1139/z83-237 ◽

1983 ◽

Vol 61 (8) ◽

pp. 1847-1851 ◽

Cited By ~ 11

Author(s):

R. L. Rausch ◽

F. H. Fay ◽

F. S. L. Williamson

Keyword(s):

The Arctic ◽

Western Coast ◽

Intermediate Hosts ◽

Alopex Lagopus ◽

New Host ◽

Host Interactions ◽

Diphyllobothrium Dendriticum ◽

Arctic Foxes ◽

Plagiorchis Elegans ◽

Toxascaris Leonina

Eight species of intestinal helminths were obtained from 38 arctic foxes, Alopex lagopus (L.), from two localities in Greenland (Thule Air Base and Søndre Strømfjord), viz., Echinoparyphium sp., 13%; Plagiorchis elegans (Rudolphi, 1802), 45%; Cryptocotyle concavum (Creplin, 1825), <3%; Diphyllobothrium dendriticum (Nitzsch, 1824), 10%; Taenia ovis krabbei Moniez, 1879, 13%; Mesocestoides lineatus (Goeze, 1782), 13%; Toxascaris leonina (von Linstow, 1902), 39%; and Uncinaria stenocephala (Railliet, 1884), <3%. New host and geographic records are reported. Cestodes for which rodents are obligatory intermediate hosts were not recorded, suggesting that the series of foxes was drawn from local populations inhabiting the western coast of Greenland. Helminth–host interactions are briefly discussed.

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

Canadian Journal of Zoology ◽

10.1139/z96-072 ◽

1996 ◽

Vol 74 (4) ◽

pp. 627-631 ◽

Cited By ~ 11

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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Evironmental threats to marine mammals in the Canadian Arctic

Polar Record ◽

10.1017/s003224740002163x ◽

1983 ◽

Vol 21 (134) ◽

pp. 433-449 ◽

Cited By ~ 12

Author(s):

Ian Stirling ◽

Wendy Calvert

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Marine Mammals ◽

Canadian Arctic ◽

Ursus Maritimus ◽

The Arctic ◽

Polar Bears ◽

Alopex Lagopus ◽

Arctic Foxes ◽

The Arctic Ocean

The Arctic Ocean is the home of three major groups of mammals that depend on the sea for survival and show varying degrees of adaptation for maritime life. Most fully adapted are the whales (Cetacea), which never leave the water, and the seals and walruses (Pinnipedia) that feed entirely at sea but emerge onto land or ice for pupping and basking. Less exclusively marine are two species of the order Carnivora—Polar Bears (Ursus maritimus), that seldom live far from the sea because they feed almost entirely upon seals, and Arctic Foxes (Alopex lagopus), some of which move out onto the sea ice during the winter, mainly to scavenge on the remains of seals killed by Polar Bears.

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