Fig. 3

Three-dimensional view of soaring movement employed by Red Kites over the land (A, B) and Adriatic Sea (C, D). The GPS position was obtained in 5-min bursts of frequency, one location per second, followed by a 10-min break. Yellow vertical lines show the projection of the 3D track over the 2D surface. The panels in the middle show the differences in oscillation of birds' speed (m s⁻¹) and gain in altitude. The panels on the right show the acceleration (z-axis, in black, mG) and the magnetometer (x-axis, in red, mGauss) signals. Oscillation on birds' speed and magnetometer reflect the circular movement