Fig. 2. (A) Two-dimensional representation of a typical take-off flight in a quail, for the three coordinates describing its three-dimensional position (x, y and z), plotted with respect to time (t). Quadratic equations have been fitted to the position data, and the r² values for these are shown. (B) Three-dimensional representation of the flight illustrated in A. The axes have been scaled such that they represent the size of the flight chamber. (C) Velocity of the centre of mass of the quail during take-off for the flight illustrated in A and B. The initial velocity of the bird (v_min) was 4.33 m s^-1, and velocity increased to a maximum of 5.74 m s^-1 (v_max) by the end of the flight. The rate of change of kinetic energy of the body was calculated using equation 9:

(U1)

The initial kinetic energy of the body is deducted in this calculation because at least some proportion of this may be contributed by the hindlimbs. , , , velocity of the centre of mass in the x, y and z directions, respectively.