Meeting Abstract
Bees are pollinators whose habitat includes cluttered vegetation that moves when blown by unpredictable winds. Careful navigation through this habitat is important because collisions can injure bees, but little is known about how bees fly in habitats with wind-blown obstacles. We used the European honey bee, Apis mellifera, to test how bees navigate through habitats with wind and moving obstacles. We filmed bees flying through a 1 m tunnel with an array of horizontally oscillating vertical columns. We tested bees flying in still air, headwinds and tailwinds, and varied the frequency of the columns’ oscillations. Bees either landed on or flew around the columns, and their flights could be divided into three distinct phases: an early approach (5 to 3.5 cm from the columns), a middle approach (3.5 – 2 cm away), and a final approach (2 – 0 cm away). The final flight behavior was strongly correlated with the columns’ acceleration during the early approach phase: bees landed on columns that had been accelerating during the early approach and flew between columns that had been decelerating. Final flight behavior was also correlated with the columns’ speed during the middle approach phase: bees landed on columns that had been moving slowly during this phase and flew between columns that had been moving rapidly. This correlation persisted over a longer portion of the middle approach if the bees were flying into a headwind. Only during the final approach did bees’ flight kinematics reflect their behavioral choice: bees that landed reduced their flight speed more than bees that flew between columns. Our results suggest that bees can navigate through environments with moving obstacles by assessing obstacle motion and deciding whether to land on or fly between obstacles from afar, and then executing that decision during the final approach.
