Fig. 1. (A) Mean daily maximum dive duration (± S.E.M.) and (B)
mean daily dive duration (± S.E.M.) recorded from female
(filled symbols) and male (open symbols) macaroni penguins during the
summer/pre-moult and winter/migration phases of their annual cycle. The solid
black bars represent the three sampling periods used in the analysis of
changes in dive duration and other variables.