Responses to novel stimuli of free-ranging small mammals along a gradient of human disturbance

Understanding how animals adjust to human presence and disturbance is critical for conservation. Behavioural plasticity is key to the expression of appropriate responses, and determines which individuals cope better in disturbed and altered environments. However, anthropogenic alterations are usually investigated within highly urbanised areas, leaving the effects of human disturbance in natural areas – where less innovation-prone animals are presumed to find refuge – relatively uninvestigated. Here we exploited a gradient of human presence and disturbance that included different levels of protection within a National Park to examine neophobia and innovation of free-living small mammals ( N = 158 observations from repeated experimental trials). We investigated: 1) how wood mice ( Apodemus sylvaticus ) respond to novel structures; 2) their propensity to express novel behaviour (i.e. innovation) in a foraging context; and 3) response pattern consistency across these different types of novel stimuli. Findings indicate spatial sorting for responses to novelty along the gradient of human disturbance. Mice living in the buffer zone displayed higher avoidance towards novel objects compared to conspecifics living in both strictly protected and non-protected areas. Foraging innovation propensity, instead, scaled positively with the degree of human presence and disturbance. Together, results suggest that even low levels of human disturbance are linked to differences in neophobia and innovation, albeit the response patterns appear context-dependent. Understanding such complex behavioural adjustments provides valuable insights for future conservation efforts, including more effective management strategies to reduce disturbance to wildlife by human activities, and to assess the actual effectiveness of protected areas and protection regimes.