Dispersion and Mortality of Colonies of the Tropical Ant Paraponera clavata

Abstract

Between 1984 and 1987 we located and recensused 217 Paraponera clavata colonies on a 50 ha plot of lowland rain forest located on Barro Colorado Island, Republic of Panama. In this study we describe patterns of dispersion of colonies of P. clavata with respect to habitat type, topography, and intercolony distance. We then used colony mortality data to determine if differential mortality contributes to observed patterns of dispersion. Colony density was 4.34/ha. Colonies were overdispersed, but were not significantly associated with habitat type or slope. Colony mortality was not significantly related to habitat type, slope, or tree species or size class. Colonies c 20 m from another colony had significantly higher mortality rates than colonies found at greater distances. Mean life expectancy of a colony was 2.5 yr. Intercolony aggression appears to be a major factor contributing to colony mortality in this species. Patterns of colony-tree association reported by Belk et al. (1989) cannot be fully explained by differential mortality, and thus appear to be due to selection by founding queens.