Fig. 8.

Calculated efficiency versus speed, body size and lunge duration (dots). Cases of the 27 m and 22 m blue whale and 8 m humpback whale listed in Table 1. Other parameters are U_close from Equation (5), ρ_prey = 0.18 kg/m³ and f = 1.45. The continuous lines correspond to data fits resulting in FE ∼ 79.15 ${\mathrm{U}}_{\text{open}}^{-1.40}$ (27 m blue whale with T_lunge = 77 s), FE ∼ 54.94 ${\mathrm{U}}_{\text{open}}^{-1.24}$ (22 m blue; T_lunge = 85 s), and FE ∼ 17.18 ${\mathrm{U}}_{\text{open}}^{-0.97}$ (8 m humpback; T_lunge = 47 s); and the dashed lines in FE ∼ 51.79 ${\mathrm{U}}_{\text{open}}^{-1.20}$ (27 m blue; T_lunge = 120 s), ∼34.95 ${\mathrm{U}}_{\text{open}}^{-1.03}$ (22 m blue; T_lunge = 130 s), and ∼9.67 ${\mathrm{U}}_{\text{open}}^{-0.72}$ (8 m humpback; T_lunge = 85 s). The dashed-double dot curves trace the efficiency without inclusion of the rest-of-body metabolic term (f = 0), thereby scaling (exactly) as FE ∼ M_water/M_body${\mathrm{U}}_{\text{open}}^2$.