Data for: Sub-zero temperatures and large-scale weather patterns induce tooth damage in Icelandic arctic foxes

Tooth damage in carnivores can reflect shifts in both diet and feeding
habits, and in large carnivores it is associated with increased bone
consumption. Variation in tooth condition in Icelandic arctic foxes, a
mesocarnivore, was recorded from 854 individual foxes spanning 29 years.
We hypothesized that annual climatic variations, which can influence food
abundance and accessibility, will influence tooth condition by causing
dietary shifts toward less edible prey. We examined tooth condition in
relation to four climatic predictors: mean annual winter temperature,
indices of both the El Niño anomaly and North Atlantic subpolar gyre
(SPG), and the number of rain-on-snow days (ROS). We found unequivocal
evidence for a strong effect of annual climate on tooth condition. Teeth
of Icelandic foxes were in better condition when winter temperatures were
higher, when the SPG was more positive, and when the number of ROS was
low. We also found a substantial subregional effect with foxes from
northeastern Iceland having lower tooth damage than those from two western
sites. Contradicting our original hypothesis that foxes from northeastern
Iceland, where foxes are known to scavenge on large mammal remains (e.g.,
sheep and horses), would show the highest tooth damage, we suggest that
western coastal sites exhibited greater tooth damage because cold winter
temperatures lowered the availability of seabirds, causing a shift in diet
toward abrasive marine subsidies (e.g., bivalves) and frozen beach wrack.
Our study shows that monitoring tooth breakage and wear can be a useful
tool for evaluating the impact of climate on carnivore populations and
that climate change may influence the condition and fitness of carnivores
in complex and potentially conflicting ways.