Figure 1.

Power curves calculated for sea-level air density from Flight 1.24, using mass and wing span from table 1, and values of k = 0.90 for the induced power factor and C_db = 0.10 for the body drag coefficient. The maximum chemical power available depends on the aerobic capacity of the heart and lungs, which is unknown, but is likely to provide a wider margin above minimum power in smaller birds, and very little margin in swans.