The ability to navigate is crucial for animals, yet navigational mechanisms are poorly understood, especially in mammals. This is so, in large part, due to technological limitations that have prevented, until recently, from tracking small animals in high spatio-temporal resolution. Here we report the first GPS-tracking of bats, using an ultra-lightweight GPS datalogger.
Egyptian fruit bats commuted from their cave to a remote fruit-tree in high, fast and very straight flights, and returned to the same individual feeding-tree night after night. Bats that were displaced 44-km south homed to one of two goal locations – cave or feeding-tree – which allowed ruling out navigation based on beaconing, route-following, or path-integration mechanisms, and suggested instead map-based navigation. Bats released within a deep natural crater exhibited severe disorientation, while bats released atop crater-edge homed well – indicating navigation by the geometric configuration of distal visual landmarks. These results provide the first evidence for a large-scale navigational map in mammals.