Fig. 5. Maximum beak angles as a function of breath sequence number (n) in surface pauses consisting of three different total breath numbers; N_max=6 (A), 10 (B) or 14 (C). Values are derived from the means of five free-living Magellanic penguins and are means ± S.E.M. Values shown are derived from a minimum of 5 readings per bird in all cases. The inset (D) shows how these values relate to a single typical 10-breath beak opening trace.