Fig. 4.

Relationship between age and high-resolution activity metrics for male (closed circles) and female (open circles) black-browed (BBA) albatrosses during the incubation and brood-guard stages. Regression lines indicate the fitted values of the average of the most supported models for each response variable. Where a significant effect of sex was found, males (dotted) and females (solid) are shown with separate lines. Horizontal lines indicate no age effect but a significant sex effect. Values of transformed response variables (a-d) are back-transformed on the y-axis but the scale of the transformation is retained