Department of Neurobiology and Cognitive Interaction Technology Center of Excellence, Bielefeld University, 33615 Bielefeld, Germany;
School of Engineering and Information Technology, University of New South Wales, Canberra 2914, ACT, Australia.
Proc Natl Acad Sci U S A. 2020 Dec 8;117(49):31494-31499. doi: 10.1073/pnas.2016872117. Epub 2020 Nov 23.
Animals that move through complex habitats must frequently contend with obstacles in their path. Humans and other highly cognitive vertebrates avoid collisions by perceiving the relationship between the layout of their surroundings and the properties of their own body profile and action capacity. It is unknown whether insects, which have much smaller brains, possess such abilities. We used bumblebees, which vary widely in body size and regularly forage in dense vegetation, to investigate whether flying insects consider their own size when interacting with their surroundings. Bumblebees trained to fly in a tunnel were sporadically presented with an obstructing wall containing a gap that varied in width. Bees successfully flew through narrow gaps, even those that were much smaller than their wingspans, by first performing lateral scanning (side-to-side flights) to visually assess the aperture. Bees then reoriented their in-flight posture (i.e., yaw or heading angle) while passing through, minimizing their projected frontal width and mitigating collisions; in extreme cases, bees flew entirely sideways through the gap. Both the time that bees spent scanning during their approach and the extent to which they reoriented themselves to pass through the gap were determined not by the absolute size of the gap, but by the size of the gap relative to each bee's own wingspan. Our findings suggest that, similar to humans and other vertebrates, flying bumblebees perceive the affordance of their surroundings relative their body size and form to navigate safely through complex environments.
动物在穿越复杂的栖息地时，必须经常应对路径上的障碍物。人类和其他具有高度认知能力的脊椎动物通过感知周围环境的布局与自身身体轮廓和行动能力的关系来避免碰撞。目前还不清楚体型小得多的昆虫是否具备这种能力。我们使用了大黄蜂，它们的体型差异很大，并且经常在茂密的植被中觅食，来研究飞行昆虫在与周围环境相互作用时是否会考虑自身的大小。经过训练在隧道中飞行的大黄蜂会偶尔遇到一堵含有宽度不同的缺口的障碍物墙。蜜蜂通过先进行侧向扫描（侧飞）来视觉评估孔径，成功地飞过狭窄的缝隙，即使缝隙比它们的翼展小得多。然后，它们在通过时调整飞行中的姿势（即偏航或航向角），最小化它们的投影正面宽度并减轻碰撞；在极端情况下，蜜蜂完全侧向飞过缝隙。蜜蜂在接近时进行扫描的时间以及它们为通过缝隙而重新定向的程度，不是由缝隙的绝对大小决定的，而是由缝隙相对于每只蜜蜂自身翼展的大小决定的。我们的研究结果表明，与人类和其他脊椎动物一样，飞行的大黄蜂感知周围环境的可及性与其身体大小和形状有关，以便在复杂的环境中安全导航。
