Handedness of brown bears aggregating in Katmai National Park, USA.

We analyzed handedness of brown bears (Ursus arctos), which is the tendency to differentially use the right or left forelimb for dexterous actions. Handedness in mammals is hypothesized to be an outcome of lateralization of neocortex function, which serves to increase cognitive capacity by reducing redundancy of function between left and right hemispheres. Handedness in brown bears would give insight into brown bear capacity for cognition and innovative behavior. We tallied brown bear forelimb use from videography of bears foraging on anadromous sockeye salmon (Oncorhynchus nerka) while aggregated at the Brooks River within Katmai National Park, Alaska, USA, during autumn 2022. Brown bears exhibited a significant propensity for handedness, a result driven primarily by brown bears using their right forelimb more often than their left to swat at conspecifics during social interactions. Under the model that neocortex lateralization increases cognitive capacity, the right-handedness we observed in brown bears is consistent with their capacity for problem solving and behavioral innovation. [ABSTRACT FROM AUTHOR]