| Popis: |
Individual dietary specialization, where individuals occupy a subset of a population’s wider dietary niche, is of key importance for species’ resilience against environmental change. However, the ontogeny of individual specialization, as well as associated underlying social learning, genetic, and environmental drivers remain poorly understood. Using a multigenerational dataset of female European brown bears (Ursus arctos) followed since birth, we discerned the relative contributions of social learning, genetic predisposition, environmental forcings, and maternal effects to individual dietary specialization. Individual specialization varied from omnivorous to carnivorous diets spanning half a trophic position. The main determinants of this dietary specialization were maternal learning during rearing (13%), environmental similarity (12%), maternal effects (11%), and permanent individual effects (8%), whereas the contribution of genetic heritability was negligible. Importantly, the offspring’s trophic position closely resembled the trophic position of their mothers during the first 3-4 years after separation from the mother, but this relationship ceased with increasing time since separation. Our study reveals that social learning and maternal effects are as important for individual dietary specialization as environmental forcings. We propose a tighter integration of social effects into future studies of range expansion and habitat selection under global change that, to date, are mostly explained by environmental drivers. |
