UCLA

Natal dispersal is the permanent movement of individuals from their natal home range to a new location for reproduction. Dispersal helps maintain genetic variation and is viewed as an adaptive behavior; however, the decision rules influencing dispersal may no longer be optimal in rapidly changing environments. Climate change creates mismatches between species’ life history traits, decision rules, and the environment, and this gap may be enhanced in species whose habitats are especially sensitive to rapid change. At least two processes can permit flexible responses in a changing environment: phenotypic plasticity and/or possessing sufficient additive genetic variation to permit evolution. While numerous studies investigate species’ plastic responses to altered environmental conditions, the potential to evolve when faced with long-term changes is often overlooked in ecological studies of dispersal. Here, we use the quantitative genetic mixed model, termed the ‘animal model’, to conduct a variance decomposition of female yellow-bellied marmot (Marmota flaviventer) natal dispersal. We found significant heritable variation in the propensity to disperse when using a 60-year data set, but our estimate was not substantially different from zero when we used a smaller 18-year data set that permitted us to account for known environmental effects that influence dispersal. Nevertheless, these findings illustrate the importance of phenotypic plasticity in dispersal decisions in this system and, overall, suggest that should yellow-bellied marmots experience a future mismatch with their environment, they have some additive genetic variation that may allow them to evolve a new optimal response.