Taylor Brian K, Lohmann Kenneth J, Havens Luke T, Lohmann Catherine M F, Granger Jesse
Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Department of Biology, Duke University, Durham, NC, USA.
J R Soc Interface. 2021 Jan;18(174):20200887. doi: 10.1098/rsif.2020.0887. Epub 2021 Jan 6.
Diverse taxa use Earth's magnetic field in combination with other sensory modalities to accomplish navigation tasks ranging from local homing to long-distance migration across continents and ocean basins. Several animals have the ability to use the inclination or tilt of magnetic field lines as a component of a magnetic compass sense that can be used to maintain migratory headings. In addition, a few animals are able to distinguish among different inclination angles and, in effect, exploit inclination as a surrogate for latitude. Little is known, however, about the role that magnetic inclination plays in guiding long-distance migrations. In this paper, we use an agent-based modelling approach to investigate whether an artificial agent can successfully execute a series of transequatorial migrations by using sequential measurements of magnetic inclination. The agent was tested with multiple navigation strategies in both present-day and reversed magnetic fields. The findings (i) demonstrate that sequential inclination measurements can enable migrations between the northern and southern hemispheres, and (ii) demonstrate that an inclination-based strategy can tolerate a reversed magnetic field, which could be useful in the development of autonomous engineered systems that must be robust to magnetic field changes. The findings also appear to be consistent with the results of some animal navigation experiments, although whether any animal exploits a strategy of using sequential measurements of inclination remains unknown.
不同的生物类群结合其他感官方式利用地球磁场来完成从本地归巢到跨大陆和海洋盆地的长距离迁徙等各种导航任务。几种动物能够将磁场线的倾角或倾斜度用作磁罗盘感知的一个组成部分，以此来维持迁徙方向。此外，一些动物能够区分不同的倾斜角度，实际上是将倾斜度用作纬度的替代指标。然而，关于磁倾角在引导长距离迁徙中所起的作用，我们知之甚少。在本文中，我们采用基于智能体的建模方法来研究一个人工智能体能否通过依次测量磁倾角成功执行一系列跨赤道迁徙。该智能体在现代磁场和反转磁场中都采用了多种导航策略进行测试。研究结果（i）表明，依次测量倾斜度能够实现南北半球之间的迁徙，（ii）表明基于倾斜度的策略能够耐受反转磁场，这对于开发必须对磁场变化具有鲁棒性的自主工程系统可能有用。这些发现似乎也与一些动物导航实验的结果一致，不过是否有任何动物采用依次测量倾斜度的策略仍不清楚。
