Magnetoreception in Cataglyphis hellenica ants.

Abstract

Magnetoreception is the ability of animals to detect and use the geomagnetic field (GMF) for spatial orientation. Cataglyphis ants are experimental models for insect navigation and magnetoreception. At the beginning of their foraging life, Cataglyphis ants perform learning walks (LWs), explorative excursions around the nest, with pirouettes (tight turns about the ants' body axes). During a pirouette, an ant gazes to the nest entrance, an invisible hole in the ground. Until now, Cataglyphis nodus has been the only desert ant species shown to use the GMF to align their gazes to the nest entrance during LW pirouettes. In the present study, we show that Cataglyphis hellenica, phylogenetically distant from C. nodus, but inhabiting the same environment, also possesses a magnetic sense. When C. hellenica ants are exposed to an experimental alteration of the GMF (alteration of the horizontal component about 180° or + 120°), they gaze to the fictive position of the nest entrance. This study demonstrates that C. hellenica ants use the GMF to gaze back to the nest entrance, confirming the presence of magnetoreception in a second Cataglyphis species, in addition to C. nodus. This suggests that the use of the GMF for path integration is rather common than unique in Cataglyphis species.