Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
Guy Theraulaz,Laboratoire d'Ethologie et de Psychologie Animale,
CNRS - UMR 5550, Université Paul Sabatier, 118 route de
Narbonne, 31062 Toulouse Cedex, France
Unit of Theoretical Behavioural Ecology, Service de Chimie-Physique,
CP 231, Université Libre de Bruxelles, Boulevard du triomphe,
1050 Brussels, Belgium
A simple response threshold model is introduced to explain the pattern of polyethism observed in the ponerine ant Ectatomma ruidum, where it was found that prey-foraging workers could be subdivided into two categories: stingers and transporters. The first group of hunters is specialized in killing live prey, and the other group in transporting dead bodies to the nest. The model can reproduce the two characteristic dynamic patterns that are experimentaly obtained by changing the number of prey initially presented to the colony.
Key-words: Polyethism, ant predation, response threshold model, task succession.