ABSTRACT
The composition of the leaf litter ant fauna of Barro Colorado Island, Panama is determined in part by competition and in part by army ant predation. A series of observations and experiments suggest that for the ant prey of Eciton burchelli both competition and the probability of army ant predation are lowest in areas just raided by these dorylines. The potential prey of army ants employ diverse and sometimes elaborate escape techniques. Eciton burchelli colonies live in Neotropical rain forest where they stage massive swarm raids. E. burchelli colonies were mapped by laying a 100m tape along each raid's principal trail. This trail is a column of ants that continuosly limks the army ants' nest and swarm. Colonies of prey species are more than twice as abundant in areas of the forest where E. burchelli does not occur, than in areas frequented by the army ants.
