Hunting, but not outdoor recreation, modulates behavioural tolerance to human disturbance in Alpine marmots Marmota marmota

Humans are often perceived as predators by free-living animals, and thus, even nonconsumptive human activities such as outdoor recreation may trigger behavioural and physiological responses, often with negative consequences on individual fitness and population persistence. Nonetheless, there is growing evidence that wildlife can also have remarkable behavioural tolerance, but no clear picture has yet emerged regarding the mechanisms explaining different responses to humans. We investigated the effect of different types of human activity – hunting and outdoor recreation – on behavioural tolerance to humans in Alpine marmots Marmota marmota. Marmots were studied in areas with contrasting protection regimes and under different levels of outdoor recreation in northern Italy over three seasons (2021–2023). Flight initiation distance (i.e. the distance at which an animal escapes from an approaching person) was used as a proxy of tolerance to human disturbance and tested against levels of outdoor recreation and hunting using linear mixed modelling. Marmots were more sensitive to human disturbance in hunted as compared to protected areas, whereas we did not find evidence for changes in behavioural tolerance when exposed to varying levels of outdoor recreation. In turn, our study suggests that hunting, by reducing behavioural tolerance to humans, could exacerbate the negative effects of non-lethal human activities on wildlife. This has implications for conservation and management strategies aimed at promoting coexistence in human-altered landscapes