Prey chain transfer behaviour in the African stink ant, Pachycondyla tarsata Fabr.

Pachycondyla tarsata workers display individual searching and hunting activ ities. Small groups of isolated individuals act as "patrollers", searching for food in the foraging territories around the nests. Finder ants returnin g laden with prey to the nest can transfer them to unladen nestmates if the y are encountered. A prey can be transferred several times, even within the nest, before it finally reaches a nest chamber. In a series of experiments on this prey chain transfer behaviour (PCTB), prey were exchanged in half of the encounters. After prey retrieval, ants involved in PCTB returned pre ferentially to prey discovery or transfer areas, according to their role in the previous transport chain. The different tasks of PCTB seem to be inter changeable among individuals in the colonies, although ants from inside the nest have a stronger tendency to remain inside while outside ants do the o pposite. Contacts between nestmates without transfer also encourage P. tars ata workers to forage, because they increase the number or the activity lev el of ants engaged in foraging labors, through the outbreak of an indirect recruitment process. It is hypothesized that PCTB works as a transport chai n that ensures the quick retrieval of prey, enabling searching and hunting activities to continue simultaneously.