Fig. 11. Modeled changes in (A) total mechanical work stroke^–1 and (B) cumulative total work, throughout descent by a Brünnich's guillemot with the respiratory volume at the water surface assumed in all other simulations in this paper (`standard', 0.153 l), and with respiratory volume at the surface increased and decreased by 60%. Total mechanical work for entire dives is annotated in the lower figure.