Animals which regularly depart from and return to fixed positions in their environment can resort to two principally different ways of navigation by usingegocentricorgeocentricsystems of reference. In the first case positional information is obtained by dead reckoning (route integration). A route-integration system provides the animal with a continuous representation of its spatial position relative to its starting point (home). Like a rigidly tightened thread of Ariadne a homeward-bound vector always connects the animal with home. In the second case, the animal is expected to use a map-based system of navigation, i.e. to obtain positional information by virtue of the spatial position it occupies in the larger environmental framework. Rather than relying on information continuously collecteden route(dead reckoning), an animal using the mental analogue of a topographical map can episodically take a positional fix, i.e. rely on information collectedon site.
展开▼
