Figure 3
Basal metabolic rate for birds. Data have been drawn from McNab22, and split into flying species (503 data, left panel) and flightless ones (22 species, right panel. Both apparent exponents (dashed lines) differ α ≈ 0.66 for flying species, and α ≈ {0.74,0.8} (depending if we consider outliers ostriches57 and emus58 in the fitting) for flightless ones. The model fit is shown in solid green line (see Table 1 for statistical tests).
