Fig. 6. Polar plots of the phase relationship between peak ventilatory airflow and the locomotor stride cycle for three individual Terrapene carolina (individual 01, black; individual 02, dark grey; individual 03, light grey). The stride cycle begins at maximum extension of the left hindlimb (0°) and continues clockwise around the polar diagram. (A) Timing of peak inhalation relative to the stride cycle in ten locomotor bouts for each of the three individuals (inhalations: N=134, 117 and 127 breaths for individuals 01-03, respectively). (B) Timing of peak exhalation (N=132, 117, and 130 breaths for individuals 01-03 respectively). Inhalations from all three individuals and exhalations from individuals 02 and 03 were randomly distributed relative to the stride cycle (Raleigh's test of circular uniformity, P>0.05). Exhalations from individual 01 showed a statistically significantly non-uniform distribution (Fig. 6B, black squares; Raleigh's test of circular uniformity, P<0.001).