Dataset for the main results of "Navigation by extrapolation of geomagnetic cues in a migratory songbird"

Preprocessed data for mean individual directions of orientation of Eurasian reed warblers (Acrocephalus scirpaceus). The dataset was used for the main result figure (Figure 3. Predictions and results for the virtual magnetic displacements) in the publication titled "Navigation by extrapolation of geomagnetic cues in a migratory songbird". This dataset shows the orientation of birds in two experiments: (1) Experiment 1 when the birds were tested under the natural magnetic field conditions (NMF), and then under the declination-only changed magnetic field condition (dCMF); (2) Experiment 2 when the orientation of birds was first tested under the NMF conditions and when all magnetic field parameters were changed (aCMF). We tested the orientation of long-distance migrants, Eurasian reed warblers, exposing them to geomagnetic cues of unfamiliar magnitude only encountered beyond their natural distribution range. The birds demonstrated re-orientation towards their natural migratory corridor as if they were translocated to the corresponding geographic location but only when all naturally occurring magnetic cues were presented, not when declination was changed alone. This result represents direct evidence for migratory birds’ ability to navigate using geomagnetic cues extrapolated beyond the range of magnitude they previously experienced.

本数据集为欧亚苇莺（Acrocephalus scirpaceus）个体平均定向方向的预处理数据集。本数据集用于发表于《迁徙鸣禽基于地磁线索外推的导航》（"Navigation by extrapolation of geomagnetic cues in a migratory songbird"）的论文中的核心结果图（图3：虚拟磁位移实验的预测结果与实测结果）。
本数据集呈现了两项实验中鸟类的定向行为：(1) 实验1：先在自然磁场（Natural Magnetic Field, NMF）条件下开展鸟类定向测试，随后切换至仅磁偏角改变磁场（Declination-only Changed Magnetic Field, dCMF）条件下继续测试；(2) 实验2：先在自然磁场条件下测试鸟类定向行为，随后切换至全磁场参数改变磁场（aCMF）条件下开展测试。
本研究针对长距离迁徙鸟类欧亚苇莺开展定向实验，向其施加了仅在其自然分布范围之外才会遇到的陌生强度地磁线索。
实验结果显示，仅当呈现全部天然地磁线索时，鸟类会朝向其自然迁徙廊道呈现出重新定向行为，仿佛被转移至对应地理位置；而仅改变磁偏角时则未出现该定向调整现象。
该结果为迁徙鸟类能够利用超出其既往经历强度范围的地磁线索进行导航提供了直接实验证据。