Desert ant navigation based on olfactory cues

Background: The desert ant Cataglyphis fortis inhabits the Tunisian saltpans. Foragers individually forage for dead arthropods and return to the inconspicuous nest entrance after tortuous routes that sometimes cover more than 1000m distance. By means of path integration foraging ants always keep track of their relative position to the nest. However, to finally pinpoint the nest entrance during homing, the ants follow a nest plume. Olfaction does to not only guide the ant home, but also has been shown to be involved in localizing food items. While foraging ants always follow food-derived plumes, homing ants follow a nest plume only, when the path integrator tells them to be close to home. Hence, the decision, whether or not to respond to an odor is not only based on the odors quality, but also on the inner state of the ant. Here, we investigate, where in the ants’ brain the decision whether or not to follow an odor plume is made.

Project Description: Behavioral experiments will be partly performed in the Tunisian saltpans during the summer months. We will furthermore establish an ant colony in the lab to perform both behavioral experiments and calcium-imaging experiments to investigate the involvement of different brain regions (e.g. the lateral horn) on odor-dependent decision making.

Candidate profile: The candidate should have a strong interest in both behavioral ecology and electrophysiology and should have experience in at least one of both topics. As the establishment of calcium-imaging in ants is extremely challenging, the candidate will first learn the well established calcium-imaging in Drosophila melanogaster and will only afterwards transfer this knowledge to the main study animal. The extremely harsh climate in the Tunisian salt pans, where most of the behavioral experiments will be performed needs to be considered.