Homing pigeons (Columba livia) modulate wingbeat characteristics as a function of route familiarity

Mechanisms of avian navigation have received considerable attention, but whether different navigational strategies are accompanied by different flight characteristics is unknown. Managing energy expenditure is critical for survival, therefore understanding how flight characteristics, and hence energy allocation, potentially change with birds familiarity with a navigational task could provide key insights into the costs of orientation. We addressed this question by examining changes in wingbeat characteristics and airspeed of homing pigeons (Columba livia) as they learned a homing task. Twenty-one pigeons were released 20 times individually from either 3.85 km or 7.06 km from home. Birds were equipped with 5 Hz GPS trackers and 200 Hz tri-axial accelerometers. We found that, as the birds' route efficiency increased during the first six releases, their median peak-to-peak dorsal body (DB) acceleration and median DB amplitude also increased. This, in turn, led to higher airspeeds, suggesti...