Antipredator Behavior in Pavement Ants, Tetramorium caespitum
Abstract
Predators and prey place each other under mutual evolutionary pressures, which
have over time shaped the behaviors of many organisms (Vermeij, 1987). Losing a predatory encounter has a higher consequence for prey than predators; therefore, prey should be under stronger selection pressures and display more extreme adaptations (Dawkins & Krebs, 1979). Previous research in ants has demonstrated several behaviors that could be antipredator adaptations, including decreased foraging behavior in areas with antlion pits, and rescuing nestmates from the pit trap of the predatory antlion (Gotelli, 1996; Czechowski et al. 2002). This project examines the antipredator responses of the ant species, Tetramorium caesiptum, to their sedentary insect predators, antlions, Myrmelontidae.
T. caespitum were placed in the vicinity of an antlion. Some ants were able to escape from the antlion after being captured. After escaping from an antlion, the ants’ behavior changed during a subsequent exposure to antlions. Learning and pheromones were explored as possible mechanisms for this behavioral shift. When an individual T. caespitum was placed near a live nestmate captured by an antlion, not all individual ants attempted to rescue their nestmate. However, the individuals that did attempt to rescue their nestmate engaged in several different behaviors that appeared to be directed toward removal of the captured ant. Furthermore, in some cases, the rescuer was successful in removing its nestmate from the mandibles of the antlion. The behaviors of T. caespitum near predatory antlions are possible antipredator adaptations.
Description
Keywords
Tetramorium caespitum, ants, behavior, predator, prey, antipredator, antlion, coevolution