Fig. 6. Coo frequency plotted against interclavicular air sac pressure (ICAS) pressure, cranial thoracic air sac (CTAS) pressure and tracheal air flow. Each plot represents a single, complete coo, and circles indicate value pairs as measured in 3-ms time frames of that coo. Circles are coded on a colour scale so that the development over time within a coo can be traced. Vertical arrows and horizontal arrows indicate the beginning and end of a coo, respectively. Each row contains three representative coos, originating from different individuals.