Fig. 5

Diel diving behavior in a winter, b spring and c summer. The relative proportion of dives completed in a given hour for pelagic (light blue) benthic (brown) and shallow water dives (bathymetry < 20 m, light grey). Average seasonal sunrise and sunset times are shown as orange bars, given the location and date of each dive in a season. Nautical twilight zones, defined as the period when the sun’s center is between 6° and 12° below the horizon, are shown adjacent to sunset and sunrise times in medium blue, while night is shown in dark blue. Absolute number of dives conducted during the day and night across the three seasons (d). Seasonal, monthly sample sizes by sex are reported in Additional file 4: Table S4-2