Desert ants: is active locomotion a prerequisite for path integration?
Desert ants Cataglyphis fortis have been shown to be able to employ two mechanisms of distance estimation: exploiting both optic flow and proprioceptive information. This study aims at understanding possible interactions between the two possibly redundant mechanisms of distance estimation. We ask whether in Cataglyphis the obviously minor contribution of optic flow would increase or even take over completely if the ants were deprived of reliable proprioceptive information. In various experimental paradigms ants were subjected to passive horizontal displacements during which they perceived optic flow, but were prohibited from active locomotion. The results show that in desert ants active locomotion is essential for providing the ants’ odometer and hence its path integrator with the necessary information.
KeywordsCataglyphis fortis Locomotion Path integration Optic flow Proprioception
We thank Andrew Martin for help in conducting the experiments. The research was funded by the Volkswagen-Stiftung (1/78 580) and the Swiss National Science Foundation (3100-61844) both to R.W.. The experiments performed in this study comply with the “Principles of animal care”, publication No. 86-23, revised 1985 of the National Institute of Health and also with the laws of Tunisia, where the experiments were performed.
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