ESM 4 from Dynamics of the energy seascape can explain intra-specific variations in sea-crossing behaviour of soaring birds NouraniE. VansteelantW. M. G. ByholmP. SafiK. 2019 Density distribution of average wind support (m/s), crosswind (m/s), and temperature gradient (delta T; °C) along the sea-crossing tracks of juvenile and adult European honey buzzards Pernis apivorus. Average values are calculated for interpolated tracks (500 m intervals; see Methods and ESM 3 for more information).