The Trail System

Abstract

Foraging trails make it easier for workers of social insects to find resources after leaving the nest (Hölldobler 1977; Shepherd 1982; Fowler and Stiles 1980). The way in which the food sites are used is thus a consequence of the distribution of the food in space (Carroll and Janzen 1973). Apart from this partitioning effect (i.e., the location of the harvesting sites within the colony territory), trails have been attributed to an aggression-reducing function between neighboring colonies whose resource-containing areas overlap (Vilela and Howse 1986; Farji Brener and Sierra 1993). According to Hölldobler and Lumsden (1980), the gradually shifting trunk trails and the area immediately around the nest are regarded as a “core area” which is the actual territory to be defended. Thus, the trails would obviously reduce the chance of aggressive confrontation between adjacent colonies. However, this hypothesis has not yet been conclusively proven for leaf-cutting ants.