Distance Measuring as Influenced by Terrestrial Cues in Cataglyphis bicolor (Formicidae, Hymenoptera)

Abstract

By means of backward, forward and lateral displacements the Influence of terrestrial cues on the distance measuring mechanism was investigated in ants, Cataglyphis bicolor, performing their return runs. In an unknown area, where visual input from horizon landmarks is excluded, the ants run in a straight course (r) 110% of the distance d between nest entrance and feeding place. This ratio r/d is systematically altered when the releasing points are situated along special lines in the known area near the nest entrance. By this a “route” can be calculated, along which the ant can find its way by means of horizon landmarks. In the desert regions of southern Tunisia that route extends up to a distance of 15 m from the nest entrance and for 5 m perpendicular to this axis.