Tracking the foraging behaviour of individual desert ants using Differential GPS

Abstract

Desert ants forage individually and without the use of chemical trails, yet can efficiently relocate their nest or a food source over long distances in barren or complex environments. Thus, they are an inspiration to engineers wishing to develop robust yet parsimonious navigational algorithms, and neuroscientists seeking to understand how tiny brains can perform such seemingly complex tasks. A range of navigation mechanisms have been hypothesised, but systematic models shown to account for and predict the ant’s behaviour are still lacking. This can be traced to two gaps in current knowledge: a log of the exact movements of the animal leading to the development of a known route, and an accurate reconstruction of the sensory information perceived throughout. Coupling such data with the known optics of the ant eye would allow researchers to reconstruct the entire visual history of the animal - the first such data-set for any animal – providing a gold standard test-bed for those seeking to understand the insect brain or develop autonomous navigation systems. In this study we sought to address both identified issues by firstly tracking individual desert ants as they traversed their natural surroundings, and then performing a high precision mapping of their visually rich habitat. Custom recording equipment was developed to augment three Leica DGPS units secured through a GEF equipment loan allowing the position and orientation of individual ants to be observed. In a separate collaboration the animal habitat was mapped using 3D laser mapping techniques allowing the sensory input experienced by the animal to be recovered.