Contributions to the life history of the Malaysian giant ant Camponotus gigas (Hymenoptera, Formicidae)

Summary:

We studied 4 polydomous colonies of the giant ant Camponotus gigas living on ca. 5 ha of primary rain forest in Borneo. Colony structure was flexible, comprising between 8 and 14 mostly subterranean nests. During the course of the study some nests were abandoned and others were established. Colonies appeared territorial with nests being connected by trails through the forest canopy. The best studied colony had a territory of 0.8 ha and a population of ca. 7000 workers, distributed unevenly among an average of 11 nests. Workers were bimorphic, majors on average weighed 372 mg and minors 135 mg. The castes differed in the morphology particularly by allometric growth of the head (mean head width 6.93 mm and 3.56 mm).¶Foraging was mainly nocturnal. At dusk large numbers of foragers (between 35 and 2287 left single nests within 75 minutes of the onset of foraging) invaded the canopy, many workers commuting between the canopy and the nests and all returning home by dawn. During the daytime foraging was reduced and was restricted to a much smaller number of workers which roamed the forest floor. C. gigas foragers collected mainly honeydew (90%) with the remainder consisting of insect prey and bird droppings. Hunting success was increased by rainfall. The numbers of foragers in each nest frequently changed naturally, but could be manipulated by altering local food supply.