Meeting Abstract
Warning signals in chemically defended organisms greatly impact the outcome of predator-prey interactions. These aposematic signals are often composed of high-contrast color patterns combined with complex behavioral movements with little locomotory function. When threatened by a predator, venomous coral snakes (genus Micrurus) display a vigorous, non-locomotory thrashing behavior that has been only qualitatively described. This thrashing display is likely a key component of a complex aposematic signal under strong stabilizing selection across species in a mimicry system. We analyzed variation in the presence and expression of the thrashing display across five species of South American coral snakes by experimentally testing snake response across simulated predator cues. We measured the duration of each thrash and the curvature along the body during the resting period after each thrash. These kinematic analyses can be performed with minimal animal handling and can cope with multiple self-occlusions and acute curvatures. We found significant variation in the propensity to perform a display at all, the duration of thrashing, and the curvature of snake bodies. This variation was mediated by predator cue type, snake body size, and species identity. Our results suggest that a high degree of variation persists in thrashing behavior exhibited by Micrurus coral snakes despite presumably strong selection to converge on a common signal. This quantitative behavioral characterization presents a new framework for analyzing the ecologically relevant motions displayed by elongate organisms.
