Figure 3.

Circular variance of movement headings of captive–raised cane toads, as a function of the localities from which their parents had been collected. Data are shown for 129 toads tracked for 5 day periods at Beatrice Hill Farm. (a) Circular variance decreased significantly with mid-parent distance from Cairns, indicating that offspring produced by parents that had been collected close to the invasion front (i.e. with high mid-parent distances) moved in straighter lines. (b) Fractal dimension (fractal D) also increased significantly with mid-parent distance, indicating less tortuous paths among toads whose parents originated closer to the invasion front.