Behavioural responses to acorn germination by tree squirrels in an old forest where white oaks have long been extirpated

► Tree squirrels are sensitive to acorn germination by removing the embryos of nondormant acorns. ► The embryo removal behaviour allows squirrels to use nondormant acorns as long-term storage. ► Our study indicates a genetic basis for such adaptive behaviour among tree squirrels.