Quick on their paws: mice living in human-disturbed areas are faster problem-solvers than mice in strictly protected areas

Cognitive and behavioural flexibility can be crucial in determining the success of animals facing fast-changing, altered, or disturbed conditions. Innovative problem-solving is considered a key trait for dealing with human-induced environmental alterations, as it can allow individuals to find solutions to novel problems that threaten their survival or reproduction. However, the link between animal innovation and human-induced habitat alteration is usually examined in urbanised areas, thereby overlooking potential effects of human disturbance in natural areas, where less innovative animals are presumed to find refuge. Here, we exploit a gradient of human presence and disturbance, epitomised by differential protection regimes in a National Park, to investigate small mammals’ innovation propensity. Using standardized tests directly in the field, we compared problem-solving performance of free-living Apodemus mice in a battery of four single-level foraging extraction tasks and a sequential multi-level extraction task of increasing difficulty. We found that mice living in the non-protected small settlements within the National Park were faster problem solvers compared to mice living in protected areas, both in single-level and multi-level tasks. Moreover, mice living in the buffer zone were initially less likely to participate in the tests and less persistent in case of failure compared to conspecifics living in strictly protected areas, but these differences eroded over time. Overall, these results suggest that even relatively low levels of human disturbance are linked to differences in behavioural and cognitive performance. Among-individual variation in problem-solving might thus play a key role in individuals’ successful coping with the rapid and recent expansion of humans across environments.