Arctic fox diet in Yamal peninsula

Abstract

Arctic fox in inland areas has been typically described as a species dependent on rodent populations, but being able to use alternative prey, therefore named an opportunistic specialist. Rodent populations in the low shrub tundra of southern Yamal peninsula exhibit at present low amplitude cycles. The hypothesis for this thesis is that the low abundance of small rodents is not enough to sustain arctic fox population numbers, and there is a need for alternative prey resources. This study uses four methods to assess the diet of the arctic fox in the low shrub tundra of southern Yamal peninsula: picture identification, identification of prey remains, scat analysis and stable isotope analysis. Results of the scat analysis showed that there was no differences between the presence of rodents in the diet in 2013 and 2014, a year with relatively higher and lower small rodent abundance respectively. The presence of birds was higher in the diet during 2013 than 2014. PCA showed a more varied diet in 2014 than in 2013, likely due to the presence of reindeer carcasses in the tundra. Stable isotope analysis supported the importance of Microtus species, previously found in the scat analysis. Correlation between numerical responses of the arctic foxes, quantified as the number of active dens, and the rodent abundance was not found. It seems that arctic foxes in the low shrub tundra of southern Yamal peninsula are following a generalist strategy.