Gray squirrel responses to heterospecific alarm calls of tufted titmice

Mammals and birds have developed alarm calls to protect and warn their kin of predators. Tufted titmice (Baeolophus bicolor) in particular have developed predator-specific alarm calls. Many avian species listen to tufted titmouse calls to gain information for increasing their own safety, also known as eavesdropping. Few studies have looked at whether mammal species eavesdrop on avian alarm calls, yet small birds and mammals often share the same predator species. In order to broaden understanding of eavesdropping responses among birds and mammals more generally, I tested for Eastern gray squirrel (Sciurus carolinensis) response to tufted titmice alarm calls. Audio playbacks of titmouse alarm calls, given in 3 different specific risk situations, and a control call were used on squirrels and their behaviors before and after playbacks were recorded. The squirrels exhibited strong antipredator behaviors in response to titmouse alarms but not controls and they discriminate between alarm types. We conclude that Eastern gray squirrels eavesdrop on tufted titmice alarm calls to help avoid predation.