Fig. 2

– Top two rows: the year-round activity of Zino’s petrels (Pterodroma madeira) in red and Desertas petrels (P. deserta) in gold, estimated based on the daily proportion of saltwater immersion recorded by the GLS. The overlaid solid blue line shows the proportion of moon illumination for the respective dates (supplementary information), highlighting days of full moon and new moon (shown as a dark circle). For each species, the non-breeding season occurs between the vertical dashed black lines. Bottom two rows: the yearly overlap in the spatio-temporal distribution of Pterodroma madeira (in red) and P. deserta (in gold). For each panel, the shapes represent the 50% (opaque) and 75% (transparent) UD contours estimated based on the GLS data. The two breeding colonies are depicted by the yellow triangles. Given their geographical proximity (distance ∼ 40 km), the two triangles overlap