Data from: Novel insights into the map stage of true navigation in non-migratory wild birds (stone curlews, Burhinus oedicnemus)

In the map-and-compass model of true navigation, animals in unfamiliar sites determine their position relative to a destination site (the map stage) before progressing towards it (the compass stage). A major challenge in animal navigation research is to understand the still cryptic map stage in general, and for free-ranging wild animals in particular. To address this challenge, we experimentally translocated wild, non-migratory birds (Stone curlews (Burhinus oedicnemus)) far from their nests and GPS-tracked their subsequent movements at high resolution and for long durations. Homing success was high, and cannot be explained by random chance or landmark navigation, implying true navigation. Although highly motivated to return home, the homing trajectories of translocated birds exhibited a distinct, two-phase pattern resembling the map and compass stages: a long, tortuous "wandering phase" without consistent approach home, followed by a short and direct "return phase". Birds re-translocated to the same site initially repeated the original wandering path but switched to the return phase earlier and after covering a smaller area; they returned home via a different path but with similar movement properties. We thus propose that birds resolve the map by acquiring, and potentially learning, the relevant navigation cues during the wandering phase.

在真实导航的地图-罗盘模型中，身处陌生环境的动物会先确定自身相对于目标位点的位置（即地图阶段），随后再朝目标行进（即罗盘阶段）。动物导航研究领域的一项核心挑战，在于阐明普遍意义上仍具隐秘性的地图阶段，尤其是针对自由活动的野生动物而言。为应对这一挑战，我们通过实验将野生非迁徙性鸟类——石鸻（Burhinus oedicnemus）——转移至远离其巢穴的区域，并以高分辨率、长时长的GPS追踪其后续移动轨迹。受试鸟类的归巢成功率极高，且无法通过随机概率或地标导航解释，这表明它们确实运用了真实导航能力。尽管这些被转移的个体有着极强的归巢动机，但其归巢轨迹呈现出清晰的两阶段模式，与地图-罗盘阶段的流程高度契合：先是一段漫长曲折的"漫游阶段"，期间并未持续朝家的方向行进；随后则进入一段简短直接的"返程阶段"。再次被转移至同一地点的鸟类，最初会重复原先的漫游路径，但会更早进入返程阶段，且此时覆盖的活动范围更小；它们会通过一条不同的路径返巢，但运动特征与此前一致。据此我们提出，鸟类可通过在漫游阶段获取（甚至学习）相关导航线索来完成地图定位。