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.