Assessing molar wear in narrow-headed voles as a proxy for diet and habitat in a changing Arctic

This paper investigates the potential of mesoscale tooth wear (mesowear, chipping, facets, and other wear attributes) in rodents as a proxy for Arctic habitat. It presents a pilot study of narrow-headed voles, Microtus gregalis, at three sites along a latitudinal gradient of ecological subzones in the Yamal Peninsula of the Russian Arctic. These sites include Kharp in the forest–tundra ecotone, Erkuta in the low Arctic, and Sabetta at the border between the low and the high Arctic. A total of 117 specimens were included and eight variables were used to characterize mesoscale tooth wear. Results show significant differences between the sites, suggesting that these variables can distinguish populations from different subzones. Kharp has the flattest tooth wear, whereas Sabetta has the most M1 occlusal relief and dentin exposure. These results are consistent with and interpreted in the light of published experimental work on captive voles. In addition, the Kharp sample has the tallest M1 crowns, whereas Sabetta has the most vertically implanted M1s. The general directional trends toward separation of values by latitude of samples suggests that mesoscale wear in hypselodont rodents (those with open-rooted, ever-growing molar teeth) reflects variation in food abrasivity and, by extension, may be valuable for tracking habitat and ecological changes in the Arctic.