Sociobiology (Dec 2015)
Fast Food Delivery: Is There a Way for Foraging Success in Leaf-Cutting Ants?
Abstract
Walking long distances through a trail system is an intrinsic feature of the leaf-cutting ants. Workers travel hundred of meters to forage by using well-defined physical routes which are cleared of vegetation or obstacles. Despite the costs of construction and maintenance, cleared trails should promote more benefits than non-physical ones, especially related to the leaf supply for the colony. Here, the leaf delivery rate in constructed and non-constructed trails was compared by counting the foraging flow and travel time of workers. Also the length and width of trails were measured. It was found that leaf delivery rate was 67.47% higher for foragers who were walking along physical trails. The forager walking speed on physical trails had an increment of 86.10%. These significant increments might be related to the truly narrow corridor present inside physical trails that are leaf litter-free, and thereby chemically stronger and smoother than non-physical ones. The speed improvement could induce the construction of longer trails which guide the workers more efficiently to the foraging patch. Thus, physical trails have an important role in foraging efficiency as they allow workers go quickly and further to forage, since they limit a path and congregate more individuals, raising the leaf delivery rate. This study provides additional information about foraging trails of leaf-cutting ants.
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