Cataglyphis desert ants have excellent navigational skills. Their main navigational mechanism is path integration. For that, they combine celestial compass cues (e.g. the position of the sun and the UV polarization pattern) and information from their idiothetic step integrator to calculate a so-called home vector. Furthermore, Cataglyphis ants use any other cue available for navigation, e.g. the landmark panorama. Before starting their foraging career outside the dark nest, the ants have to acquire all information necessary for successful navigation as foragers and to calibrate their compass systems. For that, they perform learning walks. During these short, explorative trips, the ants frequently look back to the nest entrance to take snapshots of their homing direction. Surprisingly, the ants use the earth’s magnetic field to align their gaze directions, and do not rely on celestial cues as they do during foraging. It is an open question why Cataglyphis ants use two different compass systems (celestial compass and magnetic compass) for path integration and how these two systems are linked. To understand the navigational capacities and the magnetic sense in Cataglyphis ants better, we aim to address the following open research questions:

• What are the characteristics of the magnetic compass in Cataglyphis ants? (behavioral biology)
• Where are the magnetic sensors located and how do they function? (sensory biology)
• How is compass information processed and integrated in the brain? (neurobiology)

To find answers to these key questions, we perform both behavioral and neurobiological experiments in the field in Greece and in the lab in Oldenburg.

Project question: Do ants use the Johnston’s organ to sense the magnetic field?
o   Search of sensory structures in tissue with different light and electron microscope techniques

o   Possible start date: October 2023

o   In cooperation with Prof. Dr. Michael Winklhofer and Dr. Franziska Curdt

o  Interest in understanding the magnetic sense of animals in general and in desert ants in particular
o  Prior experience with light or electron microscope techniques preferable