Fig. 4. Circular histograms of turn-angle distributions for Calopteryx aequabilis and Calopteryx maculata observed in each habitat type. Note the different scales along the internal axes (frequency) among species and habitat type. We observed a greater number of turns in stream habitat than in either forest or pasture (see Methods). Kruskal-Wallis rank-sum tests did not detect any significant turn-angle differences among the three habitats for either species.