Fig. 8. Comparison of bat wingbeat frequency (f_w) data with bird kinematics. For each bat species included in this study, the observed high-speed f_w is plotted against a f_w value calculated using the model applicable to birds from Pennycuick (1996). The values of the bat's mass, span and wing area from Table 1 are used for the calculated frequency. The upper bold line represents a regression showing that bat f_w is 50 % higher than bird f_w of similar morphological values. The lower thin line gives a hypothetical line of equivalence.