Species‐specific strategies increase unpredictability of escape flight in eared moths

Abstract

Abstract Many prey species overlap in time and space and are hunted by the same predators. A common anti‐predator behaviour is using evasive manoeuvres to escape an attacking predator. The escape‐tactic diversity hypothesis postulates that species‐specific differences in evasive behaviour will increase the overall unpredictability experienced by predators within a predator–prey community. Evolutionary, escape‐tactic diversity would be driven by the enhanced predator protection for each prey individual in the community. However, escape‐tactic diversity could also be a functional consequence of morphological differences that correlate with evasive capabilities. Echolocating bats and eared moths are a textbook example of predator–prey interactions. Moths exhibit evasive flight with diverse tactics; however, the variability of their evasive flight within and between species and individuals has never been quantified systematically. In addition, moth species show variation in size, which correlates with their flight capability. We recorded flight strength during tethered flight of eight sympatric moth species in response to the same level of simulated bat predation. Our method allowed us to record kinematic parameters that are correlated with evasive flight in a controlled way to investigate species‐specific differences in escape tactics. We show species‐specific and size‐independent differences in both overall flight strength and change of flight strength over time, supporting the escape‐tactic diversity hypothesis for eared moths. Additionally, we show strong interindividual differences in evasive flight within some species. This diversity in escape tactic between eared moths increases the overall unpredictability of evasive flight experienced by bat predators, likely providing increased protection against predatory bats for the single individual.