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）。动物导航研究中的一大核心挑战，便是全面解析至今仍鲜为人知的地图阶段，针对自由活动的野生动物而言更是如此。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）——从其巢穴处远距离异地转移，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，且无法用随机概率或地标导航来解释，这证明它们采用了真实导航模式。尽管受试鸟类有着极强的归巢动机，但其被转移后的归巢轨迹呈现出鲜明的两阶段模式，与地图-罗盘阶段的特征高度吻合：先是一段漫长曲折的“漫游阶段”，此时并未朝着家的方向持续行进；随后则是一段短促且笔直的“归航阶段”。当被再次转移至同一地点时，受试鸟类最初会重复此前的漫游路径，但会更早进入归航阶段，且在此过程中覆盖的活动范围更小；它们会通过全新路径返巢，但移动特征与此前一致。据此我们提出，鸟类可通过在漫游阶段获取（并可能通过学习掌握）相关导航线索，来完成地图阶段的定位任务。