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（map-and-compass）模型中，处于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（map stage）），随后再朝目标位点行进（即罗盘阶段（compass stage））。动物导航研究领域的核心挑战之一，便是从普遍层面阐释至今仍较为隐晦的地图阶段，而针对自由活动野生动物的相关研究则更具难度。为应对这一挑战，我们开展了实验：将野生非迁徙性的石鸻（Stone curlews，Burhinus oedicnemus）从其巢穴处远距离易地转移，并通过GPS对其后续活动进行高分辨率、长周期的追踪监测。实验对象的归巢成功率极高，且该结果无法通过随机概率或地标导航解释，这表明它们确实采用了真实导航模式。尽管这些被转移的鸟类具备极强的归巢动机，但其归巢轨迹却呈现出清晰的两阶段模式，与地图-罗盘导航的两个阶段高度契合：先是一段漫长曲折的“漫游阶段（wandering phase）”，期间并未持续朝巢穴方向行进，随后则进入一段短而直接的“归返阶段（return phase）”。当这些鸟类被再次易地转移至同一地点时，起初会重复原先的漫游路径，但会更早进入归返阶段，且活动范围也更小；它们会通过不同路径返回巢穴，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，完成地图定位。