Fig. 7. Double logarithmic plot of E against body mass (BM, kg), where E is the energy cost of walking (in lO₂kg^-1km^-1). Data for the emperor penguin (EP), the Adélie penguin (AP) and the white-flippered penguin (WfP) are derived from Pinshow et al. (Pinshow et al., 1976), data for the little penguin (LP) are derived from Baudinette and Gill (Baudinette and Gill, 1985), data for the gentoo penguin (GP) are derived from Bevan et al. (Bevan et al., 1995), data for the macaroni penguin (MP) are from Green et al. (Green et al., 2001) and data for king penguin (KP) data are from the present study. The dotted line is the regression line for all penguins other than the king penguin: logE=-0.3822logBM+0.3477, r²=0.9637, P<0.003, N=6). The solid line is the line calculated for running mammals: logE=-0.4434logBM+0.5057 (Taylor et al., 1970).