Hawkmoths' innate flower preferences: A potential selective force on floral biomechanics

While plant-pollinator interactions are a classic model system for evolutionary relationships, the relationship between forager energetics and floral motions remains little explored. In this study, we show that hawkmoths preferentially feed on horizontally oscillating flowers, which have previously been shown to yield higher energy gains during feeding bouts than looming flowers. We also analyze natural flower motions exhibited by four hawkmoth-pollinated species. Our analysis shows these flowers have higher amplitude motions in the horizontal axis than that in the looming axis. This work demonstrates the potential for adaptation between the biomechanical determinates of flower motions and the feeding performance of hawkmoths.