Fig. 1. The relationship between heart rate (beats min^–1) and rate of oxygen consumption (ml O₂ h^–1 kg^–0.60) in each of the four sub-adult Steller sea lions, plotted with the corresponding least-squares fitted linear regression (see Table 2). Each regression was fitted to all types of data available in an animal's set: swim and dry trials, and holds. See text for details.