Fig. 1

– Left panel. Heatmap depicting the results of the wind model, showing the effect of wind Δangle and wind intensity on the ground speed of the two species. Right panel. Boxplot showing the relative difference in temporal duration required to complete the real (“own”) and simulated (“other”) tracks performed by Pterodroma madeira (in red) and P. deserta (in gold), during their observed breeding season (“own season”) and during that of the other species (“other season”). For each species, the relative difference in duration was calculated using as reference the average duration of the real data (i.e., “own” tracks carried out during their “own” season). The box represents the interquartile range and the solid line shows the median duration. The petrel silhouettes highlight significant differences in track duration (see results in main text)