Project 10

Bimodal navigation in desert ants: The role of vision and olfaction

Supervisors: Dr. Markus Knaden, Hannah Rowland, MPI for Chemical Ecology

Background: Desert ants of the genus Cataglyphis forage individually in the open saltpans of Tunisia. To find their way back after long foraging runs, the ants perform path integration (i.e. always keep track their walking directions and distances and based on that compute their position relative to the nest entrance). As this system is error prone the ants in addition learn visual and olfactory landmarks to e.g. pinpoint the nest entrance (Knaden and Graham 2015). 

Project Description: While we know a lot, how the ants make use of the individual sensory modalities (vision, olfaction) for navigation, we have only a limited understanding on how both systems interfere. We e.g. could show that ants learn combined visual-olfactory nest-cues much faster than just visual or olfactory ones (Steck et al. 2011). However, we now want to test, if ants generally become better oriented, when a complex environment provides them both with visual and olfactory information. We, therefore will train ants in a situation, where they have to learn to follow a complex array of either visual or olfactory landmarks. We will compare the performance of these ants with those of ants, that are trained with combined visual and olfactory cues. The target is to understand, when ants rely either more on visual or on olfactory cues, and when they benefit from the combination of both.

Candidate profile: The candidate needs profound interest and knowledge in animal behavior and field work. Experiments in the ants’ habitat, the saltpans of Tunisia, are extremely demanding regarding the candidate’s fitness and sun/heat tolerance but at the same time reward with a well established biological system where research hypotheses can be tested by straightforward experiments. The candidate will organize and conduct 10 weeks of field work per year (with on-site supervision during the first week and help by 1 or 2 student helpers during the remaining time.

References:

  • Knaden, M., Graham, P. (2016). The sensory ecology of ant navigation: from natural environments to neural mechanisms. Annual Review of Entomology, 61, 63-76.
  • Steck, K., Hansson, B. S., Knaden, M. (2011). Desert ants benefit from combining visual and olfactory landmarks. The Journal of Experimental Biology, 214, 1307-1312.

pdf-project 10