The Role of Trail Junctions on Traffic Organization in the Army Ant Eciton burchellii

Abstract

Army ants (Eciton burchellii) have been studied for nearly a century, but observable patterns in their traffic organization have not yet been explored, despite the fact that this organization contributes greatly to their optimal foraging. Using pheromones and tactile cues to transmit information from ant to ant, they coordinate their movements in order to optimize traffic and create a collective behavior that increases the overall efficiency of the colony. Garnier et al. (2013) discovered that E. burchellii traffic possesses regular, periodic oscillations that allow it to gain maximum stability. In this paper, we explored these traffic oscillations at trail junctions to determine how army ants optimize their network of foraging trails. After conducting research at La Selva Biological Station in Costa Rica, we found that the mean oscillation frequencies and periods of army ant traffic are uniform and unrelated to traffic direction. Despite this overarching uniformity, each zone of a trail junction possesses a different oscillation frequency compared to the other two zones of the same junction. Lastly, oscillation frequency increases as traffic becomes more unidirectional. By displaying differential oscillatory behavior at trail junctions, army ants spontaneously adapt to their constantly changing environment in order to optimize traffic dynamics. Finally, we propose ideas for future research that have the potential to delve deeper into the study of trail junctions.