Department of Psychology, University of Alberta, Edmonton, AB, Canada, T6G 2E9.
School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia.
J Exp Biol. 2024 Jan 15;227(2). doi: 10.1242/jeb.246695. Epub 2024 Jan 25.
Maintaining positional estimates of goal locations is a fundamental task for navigating animals. Diverse animal groups, including both vertebrates and invertebrates, can accomplish this through path integration. During path integration, navigators integrate movement changes, tracking both distance and direction, to generate a spatial estimate of their start location, or global vector, allowing efficient direct return travel without retracing the outbound route. In ants, path integration is accomplished through the coupling of pedometer and celestial compass estimates. Within path integration, it has been theorized navigators may use multiple vector memories for way pointing. However, in many instances, these navigators may instead be homing via view alignment. Here, we present evidence that trail-following ants can attend to segments of their global vector to retrace their non-straight pheromone trails, without the confound of familiar views. Veromessor pergandei foragers navigate to directionally distinct intermediate sites via path integration by orienting along separate legs of their inbound route at unfamiliar locations, indicating these changes are not triggered by familiar external cues, but by vector state. These findings contrast with path integration as a singular memory estimate in ants and underscore the system's ability to way point to intermediate goals along the inbound route via multiple vector memories, akin to trapline foraging in bees visiting multiple flower patches. We discuss how reliance on non-straight pheromone-marked trails may support attending to separate vectors to remain on the pheromone rather than attempting straight-line shortcuts back to the nest.
维持目标位置的位置估计是动物导航的基本任务。包括脊椎动物和无脊椎动物在内的许多动物群体都可以通过路径整合来完成这一任务。在路径整合过程中，导航者整合运动变化，跟踪距离和方向，生成其起始位置或全局向量的空间估计，从而无需回溯外出路线即可高效地直接返回。在蚂蚁中，路径整合是通过计步器和天体罗盘估计的耦合来完成的。在路径整合中，有人认为导航者可能会使用多个向量记忆来进行路线指向。然而，在许多情况下，这些导航者可能会通过视准线来归巢。在这里，我们提供的证据表明，跟随痕迹的蚂蚁可以关注它们全局向量的片段，以重新追踪它们非直线的信息素痕迹，而无需熟悉的视野的干扰。在陌生的地点，通过沿入站路线的不同腿定向，定向不同的中间站点，表明这些变化不是由熟悉的外部线索触发的，而是由向量状态触发的。这些发现与蚂蚁中作为单一记忆估计的路径整合形成对比，并强调了该系统通过多个向量记忆在入站路线上指向中间目标的能力，类似于蜜蜂在访问多个花斑时的巡回觅食。我们讨论了依赖非直线信息素标记的痕迹如何支持关注单独的向量以保持在信息素上，而不是试图直接返回巢穴。
