Distribution, mortality and association with plants of Paraponera clavata (Hymenoptera : Formicidae) nests in Barro Colorado Island, Panama

We studied the distribution, mortality and association with plants, of 308 nests of the neotropical ant Paraponera clavata, in a permanent 50 hectare plot in old-growth forest on Barro Colorado island between September 1993 a nd February 1995. Ant nests were uniformly dispersed throughout the plot, a nd significantly associated with the high plateau and patch of young forest in the plot. The average density was 6.2 nests per hectare. Mortality of n ests was higher with increasing number of neighbors within 20 m, compared t o those separated at greater distances. The mortality was between 13.36% an d 69.64% depending on the census interval, and recruitment between 22.63% a nd 31.72%. The nests were found in 84 plant species of 34 families, pertain ing to four life forms: 76 species were trees, 5 were shrubs, 2 were palms and one was a liana. We tested for association between ant nests and tree s pecies and tree size by examining whether nests were more common in certain categories than would be expected by change. Eight species of plants were positively associated with Paraponera clavata. The ant preferentially selec ted trees between 8 and 63.9 cm diameter at breast height. Trees and small shrubs were not associated with the nests. No association was found between ant nests and trees with extra-floral nectaries. Fifty-three percent of th e nests had a Phrynus gervaisii (Amblypygi: Phrynidae) cohabiting inside. T hese nests had lower mortality rates than the rest.