One of society's great challenges centers on how to maintain biodiversity during the ongoing period of rapid global environmental change. Although plants and animals can respond to environmental change by moving to a different area, they could also adapt in place through either plasticity (e.g. by changing behaviors to match the conditions) or by rapid evolutionary change via natural selection. The option of rapid adaptation in place via plasticity or evolution remains relatively unstudied. Research in this area is critical because the fate of wild species in a rapidly changing environment will depend in large part on the scope of this adaptive rescue. For 21 bird and mammal species globally, survival depends on camouflage arising from seasonal color molts from brown to white to track the winter presence of snow. Because a decreasing winter snow duration is one of the most pervasive outcomes of ongoing climate change, these animals increasingly find their winter white camouflage compromised against increasingly brown snowless backgrounds. This research will use field studies, captive experiments, and genetic analyses with snowshoe hares as a model to provide general scientific insights to foster adaptive rescue - and therefore biodiversity persistence - in a changing world.
This study will evaluate the scope for adaptive rescue to climate change in a visually compelling model system based on polymorphic snowshoe hare populations with sympatric winter brown and winter white individuals. Field studies (including radiotagging wild animals) will directly measure fitness costs and behavioral plasticity for the sympatric winter color morphs. Captive experiments with the polymorphic hares will quantify the scope for hares to recognize their own coat color mismatch and behave to reduce either mismatch or risk of predation. Collectively, the field and captive experiments will form the basis of a mechanistic map linking genotype and trait phenotype in a polymorphic population to mean fitness and population growth, while explicitly accounting for behavioral plasticity and the dispersal of adaptive phenotypes.In addition to these contemporary measures of natural selection and behavioral plasticity, georeferenced snowshoe hare specimens archived in natural history collections will facilitate genetic tests for temporal evolutionary responses in the alternative camouflage phenotypes. Overall, this research program links ecological and evolutionary drivers of seasonal camouflage in snowshoe hares and provides a framework to predict how adaptive variation at this fitness-critical trait will respond to future environmental changes.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
