Mahdieh Tourani, Mark Hebblewhite, Mihai Pop, Teodora Sin, Andrea Gazzola, Viorel Popescu

As human activity expands worldwide, understanding wildlife responses to anthropogenic pressures is essential for supporting human-wildlife coexistence. Importantly, anthropogenic impacts are highly heterogeneous among species and can reshape entire mammal assemblages. This motivates the use of community-level approaches that capture both shared and species-specific responses. We evaluated the spatiotemporal responses of a stable mammal community, including brown bears, to human activity in the Romanian Carpathians, one of Europe’s largest strongholds for large carnivores.
Using camera-trap data, we fit Bayesian community occupancy models separately for summer and winter to estimate wildlife responses while accounting for imperfect detection. We additionally quantified seasonal activity overlap between humans and wildlife. Brown bears were widespread across sampling locations in both seasons and were among the most detectable species, particularly in summer, indicating consistent site use despite human presence. Wildlife responses to human activity varied among species and between seasons. Temporal overlap with humans also differed across the community, with brown bears exhibiting intermediate overlap across seasons, suggesting partial temporal adjustment rather than complete avoidance.
By borrowing strength across species, the hierarchical community framework produced reliable estimates of mammal responses to human disturbance. Data from frequently detected species, such as the brown bear, improved precision for rare taxa such as the Eurasian lynx. These findings highlight the value of community-level approaches for simultaneously quantifying community-wide patterns and species-specific responses while improving the precision of estimates for low-detection species. This framework could be a useful tool for conservation planning in human-dominated landscapes, with relevance for rare populations, such as the Marsican brown bear.