The Common Loon (Gavia immer) is an aquatic diving bird that lives in freshwater habitats in Canada and the northern U.S.. Human activity on a loon’s resident lake may affect its fitness and behavior, yet few studies identify or quantify these effects. We modified existing techniques that measure escape distances in other species to measure tameness as the distance at which individual loons dove in response to human approach by canoe. Tameness was similar between pair members, suggesting that common lake conditions or the behavior of a mate might influence the behavior. Sex, size within sex, and human activity did not influence tameness. However, our data for human activity characterized a lake for an entire breeding season rather than measure the amount of human activity present at the time tameness data was collected. Further studies using our technique for measuring tameness are needed to determine whether tameness is a result of the momentary influence of lake activity, a learned response, or if loons are unable to adjust their behavior in response to human activity. If loons do not have the ability to adjust their behavior to human activity, greater or more rigid set-back distances could be implemented to protect them from potential harm
