A method for identifying the nearby spatial cues used by animals during transverse orientation

A method was proposed to locate the nearby cues used by an animal in the case of transverse orientation, where the animal keeps a constant angle with a spatial cue. By studying the value constancy of the angles formed by a moving animal and the direction of all spatial points (constancy being expressed through more or less strong variances), we set up a cartography of the neighbouring space of this animal during a path. Relatively to the area where a low variance is found for angular values, the animal maintains the best angular constancy. The orientating cue used during this path is probably included in this area. The method efficiency is first tested on path models, and then applied to filmed walking crickets. Its heuristic value is established whenever the observer do not want a priori assess the cues the animal is supposed to choose. The practical interest of the method lies in the knowledge it provides of the relative role played by the body axis translations and rotations in the visual fixation and retinal scanning of crickets.