Meeting Abstract
Predators and prey often exhibit coupled dynamics, especially during pursuit and evasion. These interactions require the coordination of complex sensorimotor control on rapid timescales, with a high potential cost for prey. Many predators and prey have co-evolved over time, resulting in an evolutionary arms race that can influence morphology and behavior. In this study, we investigate the pursuit and evasion strategies, respectively, of Swainson’s hawks Buteo swainsoni and Brazilian free-tailed bats Tadarida brasiliensis. Bats are not typical prey of Swainson’s hawks, but a small population of these birds have specialized to prey upon the seasonal population of free-tailed bats outside of one cave in central New Mexico. We recorded, with stereo video, the pursuit and evasion of hawks and bats during flight, and reconstructed 3D trajectories of individuals. From the trajectories we quantified flight behavior of predators including path, speed, attack angle, and acceleration; for the prey we quantified escape success, escape trajectory, flight speed, acceleration, escape angle, and reaction distance. We found mixed strategies for pursuit among hawks, and no stereotypical evasion strategies among individual bats. Our results suggest that the behavior of these populations has not likely co-evolved. Further, these findings suggest the strong potential for generalized antipredator responses in other species exhibiting localized, specialized predator-prey relationships.
