Department of Biology, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
Integr Comp Biol. 2011 Dec;51(6):944-56. doi: 10.1093/icb/icr006. Epub 2011 May 11.
Directed aerial descent (DAD) is used by a variety of arboreal animals to escape predators, to remain in the canopy, and to access resources. Here, we build upon the discovery of DAD in ants of tropical canopies by summarizing its known phylogenetic distribution among ant genera, and within both the subfamily Pseudomyrmecinae and the genus Cephalotes. DAD has multiple evolutionary origins in ants, occurring independently in numerous genera in the subfamilies Myrmicinae, Formicinae, and Pseudomyrmecinae. Ablation experiments and video recordings of ants in a vertical wind tunnel showed that DAD in Cephalotes atratus is achieved via postural changes, specifically orientation of the legs and gaster. The occurrence of DAD in Formicinae indicates that the presence of a postpetiole is not essential for the behavior. Evidence to date indicates that gliding behavior is accomplished by visual targeting mediated by the compound eyes, and is restricted to diurnally active ants that nest in trees. Occlusion of ocelli in Pseudomyrmex gracilis workers had no effect on their success or performance in gliding. Experimental assessment of the fate of ants that fall to the understory showed that ants landing in water are 15 times more likely to suffer lethal attacks than are ants landing in leaf litter. Variation in both the aerodynamic mechanisms and selective advantages of DAD merits further study given the broad taxonomic diversity of arboreal ants that engage in this intriguing form of flight.
定向空中降落（DAD）被各种树栖动物用于逃避捕食者、留在树冠层以及获取资源。在这里，我们总结了 DAD 在热带树冠层蚂蚁中的已知系统发育分布，以及在伪切叶蚁亚科和 Cephalotes 属内的分布，从而对 DAD 在蚂蚁中的发现进行了补充。DAD 在蚂蚁中有多种进化起源，在 Myrmicinae、Formicinae 和 Pseudomyrmecinae 亚科的众多属中独立发生。对 Cephalotes atratus 蚂蚁进行的消融实验和垂直风洞中的视频记录表明，DAD 通过姿势变化来实现，特别是腿部和腹部的定向。在 Formicinae 中出现的 DAD 表明，后腹节的存在对于该行为并非必不可少。迄今为止的证据表明，滑行行为是通过复眼介导的视觉瞄准来完成的，并且仅限于在树上筑巢的日间活动的蚂蚁。对 Pseudomyrmex gracilis 工蚁的眼柄进行遮挡，对它们滑行的成功或表现没有影响。对掉落到底层林的蚂蚁命运的实验评估表明，落入水中的蚂蚁遭受致命攻击的可能性是落入落叶中的蚂蚁的 15 倍。鉴于参与这种有趣的飞行形式的树栖蚂蚁具有广泛的分类多样性，DAD 的空气动力学机制和选择优势的变化值得进一步研究。
