Fig. 4 in Stopped Dead in Their Tracks: The Impact of Railways on Gopher Tortoise (Gopherus polyphemus) Movement and Behavior

Fig. 4. Principal component analysis (PCA) with 95% confidence ellipses comparing tortoise behavior expressed over a one-hour observation period. Confidence ellipse fills are based on railway familiarity in addition to the control group. Control tortoises fall well outside the multivariate space of tortoises placed in the railway, demonstrating the inability of tortoises to cross railways.