Ingrid A. Anderson1, Alexander E. Primus1, Joanna Reuter2, Sean T. Sturges2, and Kirstin L. Whitmore1
1Department of Biology, Carleton College, Northfield, MN, 55057
2Department of Geology, Carleton College, Northfield, MN, 55057
Abstract. Deciphering the complex foraging patterns of Atta cephalotes has been a challenge to many researchers. The primary goal of this project, which was carried out at the La Selva Biological Station during the first two weeks of December 1998, was to examine the hypothesis proposed by Wetterer (1994) that Paraponera clavata influence A. cephalotes foraging patterns and behavior. We observed an attack in which P. clavata killed and discarded A. cephalotes foragers. This attack correlated with the cessation of A. cephalotes foraging on the tree, providing confirmation that the observation on which Wetterer based his hypothesis was not anomalous. Other observed encounters between members of the two species were seemingly neutral; in most instances, no aggression was observed. Experimental results suggest that the presence of P. clavata does not entirely preclude A. cephalotes foraging. The spatial distribution of P. clavata nests with respect to A. cephalotes nest entrances in the Arboleda does not reflect any interaction. From mapping, it was also found that nests of P. clavata are closer to Pentaclethra macroloba than expected. Comparison with results from Bennet and Breed (1985) suggests that the P. clavata nests have a uniformly spaced distribution through time. In spite of these results, how frequently P. clavata exhibit attack behavior, how much of an effect it has on overall A. cephalotes foraging, and what factors control the occurrence of the interaction remain as outstanding questions in need of further investigation.