title: Correlates between feeding ecology and mercury levels in historical and modern arctic foxes (Vulpes lagopus).
abstract: Changes in concentration of pollutants and pathogen distribution can vary among ecotypes (e.g. marine versus terrestrial food resources). This may have important implications for the animals that reside within them. We examined 1) canid pathogen presence in an endangered arctic fox (Vulpes lagopus) population and 2) relative total mercury (THg) level as a function of ecotype ('coastal' or 'inland') for arctic foxes to test whether the presence of pathogens or heavy metal concentration correlate with population health. The Bering Sea populations on Bering and Mednyi Islands were compared to Icelandic arctic fox populations with respect to inland and coastal ecotypes. Serological and DNA based pathogen screening techniques were used to examine arctic foxes for pathogens. THg was measured by atomic absorption spectrometry from hair samples of historical and modern collected arctic foxes and samples from their prey species (hair and internal organs). Presence of pathogens did not correlate with population decline from Mednyi Island. However, THg concentration correlated strongly with ecotype and was reflected in the THg concentrations detected in available food sources in each ecotype. The highest concentration of THg was found in ecotypes where foxes depended on marine vertebrates for food. Exclusively inland ecotypes had low THg concentrations. The results suggest that absolute exposure to heavy metals may be less important than the feeding ecology and feeding opportunities of top predators such as arctic foxes which may in turn influence population health and stability. A higher risk to wildlife of heavy metal exposure correlates with feeding strategies that rely primarily on a marine based diet.
authors.affiliation: Department of Vertebrate Zoology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Natalia
authors.initials: N
authors.lastname: Bocharova
authors.forename: Gabriele
authors.initials: G
authors.lastname: Treu
authors.forename: Gábor Árpád
authors.initials: GÁ
authors.lastname: Czirják
authors.forename: Oliver
authors.initials: O
authors.lastname: Krone
authors.forename: Volker
authors.initials: V
authors.lastname: Stefanski
authors.forename: Gudrun
authors.initials: G
authors.lastname: Wibbelt
authors.forename: Ester Rut
authors.initials: ER
authors.lastname: Unnsteinsdóttir
authors.forename: Páll
authors.initials: P
authors.lastname: Hersteinsson
authors.forename: Gereon
authors.initials: G
authors.lastname: Schares
authors.forename: Lilia
authors.initials: L
authors.lastname: Doronina
authors.forename: Mikhail
authors.initials: M
authors.lastname: Goltsman
authors.forename: Alex D
authors.initials: AD
authors.lastname: Greenwood
mesh_terms: D000818:Animals; D060435:Carnivory; D017753:Ecosystem; D056727:Endangered Species; D004785:Environmental Pollutants / Q000378:metabolism*; D005260:Female; D005589:Foxes / Q000276:immunology / Q000378:metabolism*; D006197:Hair / Q000378:metabolism; D007055:Iceland; D008297:Male; D008628:Mercury / Q000378:metabolism*; D011235:Predatory Behavior; D014124:Toxoplasmosis, Animal / Q000276:immunology
chemical_list: D004785:Environmental Pollutants; D008628:Mercury