Buffering effects of shelter and palatable foods mitigate fear responses in foraging wild mice.

Animal responses to fear cues are shaped by competing motivations such as hunger, access to mates and safety. In our previous work, wild mice (Apodemus spp.) showed little reaction to non-native predator scents. To test if native predator scents would elicit stronger reactions, we deployed fully enclosed laboratory chambers alongside a highly palatable food and olfactory cues from native foxes and cats and three types of controls, an herbivore scent (deer) and two procedural controls of wet and dry scent probes (the substrate on which we presented the scents) in the field. Despite using ontogenetically and evolutionarily relevant predator scents, mice showed no overt fear responses at any time, and only trivial behavioral differences between treatments. However, response variance was markedly higher for wet and dry controls compared to those exposed to animal-derived scents, suggesting a relatively greater perception of safety in chambers without scents. Collectively, these findings indicate that increased motivation for food and shelter during winter months buffered measurable responses to native predator scents. We conclude that the interpretation of risk sensitive behavior under natural conditions must account for ecological context, including shelter and food resources embedded within experimental assays, as well as seasonal tradeoffs associated with foraging decisions.