With a little help from my friends: individual and collaborative performance during trail clearing in leaf-cutting ants

Social organisms express collaborative behaviours, allowing them to solve problems that exceed their individual capabilities. Group coordination and environmental context are some of the factors that may determine the performance of individual and collaborative strategies. Using the trail-clearing behaviour of leaf-cutting ants, we evaluated experimentally for both strategies whether the success probability and clearing time depend on problem characteristics and context. We placed obstacles of different sizes and shapes (problem characteristics), in trails with different foragers’ fluxes and soil roughness (context) in 10 field nests of Atta cephalotes, and compared removal success (i.e. if ants could remove obstacles) and time of individual and collaborative strategies. Very large obstacles could only be removed collaboratively, confirming individual limitations for transporting large objects. For all obstacle shapes, collaborative removals were more successful but took longer, suggest...