Changes in dental wear and breakage in arctic foxes across space and time: Evidence for anthropogenic food subsidies?

Increased human presence in the Arctic may affect its vulnerable ecosystems. Effects on arctic and red foxes provide notable examples. Both have been documented to take anthropogenic subsidies when available, which can change diet and ranging patterns in complex ways that can either benefit or harm populations, depending on the situation. Understanding this complexity requires new tools to study impacts of increasing human presence on endemic mammals at high latitudes. We propose that dental ecology, specifically tooth wear and breakage, can offer important clues. Based on samples of arctic foxes (Vulpes lagopus Linnaeus, 1758) trapped prior to (n = 78) and following (n = 57) rapidly growing human presence on the Yamal Peninsula, Russia, we found that foxes trapped recently in proximity to human settlement had significantly less tooth wear and breakage. This is likely explained by a dietary shift from consumption of reindeer carcasses (Rangifer tarandus Linnaeus, 1758) including bone to softer human-derived foods, especially when preferred smaller prey (e.g., West Siberian lemmings, Lemmus sibiricus Kerr, 1792 and arctic lemmings, Dicrostonyx torquatus Pallas, 1778) are unavailable. These results suggest that tooth wear can be a useful indicator of the consumption of anthropogenic foods in arctic foxes.