Figure 2.

(a) Predictions of the dynamic model and (b) radio telemetry observations of eight individuals in terms of time allocation spent diving versus time available to forage in current velocities ranging from 0.1 to 1.3 m s⁻¹. In both the model and observations, eiders avoided fast currents when foraging was unprofitable. Surprisingly, foraging effort was primarily concentrated during medium currents, and relatively little foraging effort was exhibited during slack currents when it was most profitable to dive. Error bars are standard deviations across sensitivity analysis or individuals, for the model and empirical data, respectively. Black bars, per cent of total dives; grey bars, per cent time available.