Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616, USA
Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616, USA.
J Exp Biol. 2020 Jul 30;223(Pt 14):jeb222471. doi: 10.1242/jeb.222471.
Bees often forage in habitats with cluttered vegetation and unpredictable winds. Navigating obstacles in wind presents a challenge that may be exacerbated by wind-induced motions of vegetation. Although wind-blown vegetation is common in natural habitats, we know little about how the strategies of bees for flying through clutter are affected by obstacle motion and wind. We filmed honeybees flying through obstacles in a flight tunnel with still air, headwinds or tailwinds. We tested how their ground speeds and centering behavior (trajectory relative to the midline between obstacles) changed when obstacles were moving versus stationary, and how their approach strategies affected flight outcome (successful transit versus collision). We found that obstacle motion affects ground speed: bees flew slower when approaching moving versus stationary obstacles in still air but tended to fly faster when approaching moving obstacles in headwinds or tailwinds. Bees in still air reduced their chances of colliding with obstacles (whether moving or stationary) by reducing ground speed, whereas flight outcomes in wind were not associated with ground speed, but rather with improvement in centering behavior during the approach. We hypothesize that in challenging flight situations (e.g. navigating moving obstacles in wind), bees may speed up to reduce the number of wing collisions that occur if they pass too close to an obstacle. Our results show that wind and obstacle motion can interact to affect flight strategies in unexpected ways, suggesting that wind-blown vegetation may have important effects on foraging behaviors and flight performance of bees in natural habitats.
蜜蜂经常在植被杂乱和风向不可预测的栖息地觅食。在风中导航障碍物是一个挑战，而植被的风致运动可能会使这个挑战更加严重。虽然风致植被在自然栖息地中很常见，但我们对蜜蜂在杂乱中飞行的策略如何受到障碍物运动和风向的影响知之甚少。我们在一个无气流的飞行隧道中拍摄了蜜蜂在有顶风和尾风的情况下飞过障碍物的情况。我们测试了当障碍物处于运动状态和静止状态时，它们的地面速度和居中行为（相对于障碍物中线的轨迹）如何变化，以及它们的接近策略如何影响飞行结果（成功通过与碰撞）。我们发现，障碍物的运动会影响地面速度：在无气流中，蜜蜂在接近运动的障碍物时比接近静止的障碍物飞行速度慢，但在顶风和尾风中接近运动的障碍物时，它们往往会飞得更快。在无气流中，蜜蜂通过降低地面速度来降低与障碍物（无论是运动的还是静止的）碰撞的几率，而在风中的飞行结果则与地面速度无关，而是与接近时居中行为的改善有关。我们假设，在具有挑战性的飞行情况下（例如，在风中导航运动的障碍物），蜜蜂可能会加快速度，以减少如果它们飞过障碍物太近而发生的翅膀碰撞次数。我们的结果表明，风和障碍物的运动会以意想不到的方式相互作用，影响飞行策略，这表明风吹动的植被可能对蜜蜂在自然栖息地中的觅食行为和飞行性能有重要影响。
