A central issue in ecology is how animals respond to dynamically changing environments. Flying and swimming animals are likely to adjust their air velocity relative to flows in unfavorable lateral winds or currents to reach goals accurately. Air velocity is often estimated by subtracting wind velocity measured on site or from satellite scatterometers from animal ground velocity calculated from animal-borne GPS or telemetry data, but this method is restricted to the movement on a coarse time scale of several hours to a few days due to the limited resolution of available current tracking and wind data.

We developed a new method that enables estimation of air velocity and wind velocity using only the GPS tracking data sampled at every minute.Our method uses fluctuations of animal movement along their homing course to enables estimation of both air-velocity and animal encountered wind velocity using ground velocity calculated from GPS tracking data. We demonstrated that seabirds homing from their foraging sites adjusted their air velocity to cancel the lateral drift by winds. Our result suggests that the seabirds recognize the direction of their colony from over 200 km away and can control their head direction accurately over featureless ocean.