Individual and collective problem-solving in a foraging context in the leaf-cutting ant Atta colombica
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In this paper we investigate the flexibility of foraging behavior in the leaf-cutting ant Atta colombica, both at the individual and collective levels, following a change in the physical properties of their environment. We studied in laboratory conditions the changes occurring in foraging behavior when a height constraint was placed 1 cm above part of the trail linking the nest to the foraging area. We found that the size and shape of the fragments of foraging material brought back to the nest were significantly modified when the constraint was placed on the trail: independent of their size, forager ants cut smaller and rounder fragments in the presence of a height constraint than in its absence. This size adjustment does not require any direct sensory feedback because it occurred when the ants cut fragments in the foraging area; no further cutting was done when they encountered the constraint. This points to the existence of a template that ants store and use as a reference to adjust their reach while cutting. Remarkably, despite the decrease in the foraging material brought to the nest per capita the colony was still able to improve its foraging performance by doubling the number of transporters. This study illustrates the flexibility of foraging behavior exhibited by an ant colony. It provides a rare example of insects finding an intelligent solution to a problem occurring in a foraging context, at both the individual and collective levels.
KeywordsLeaf-cutting ants Foraging behavior Flexibility Recruitment Crowding Learning
We thank M. Gauthier and M. Giurfa for helpful discussions. A. D. was supported by a mobility fellowship (bourse de co-tutelle Belgique-France) from the French Ministry of Scientific Research and a fellowship (ATUPS) from Paul Sabatier University (Toulouse, France). J. L. D. is a research associate from the Belgian National Fund for Scientific Research.
- Aiken LS, West SG (1991) Multiple regression: testing and interpreting interactions. Sage Publications, Newbury ParkGoogle Scholar
- Bonabeau E, Dorigo M, Theraulaz G (1999) Swarm intelligence—from natural to artificial systems. Oxford University Press, OxfordGoogle Scholar
- Camazine S, Deneubourg J-L, Franks N, Sneyd J, Theraulaz G, Bonabeau E (2001) Self-organization in biological systems. Princeton University Press, PrincetonGoogle Scholar
- Detrain C, Deneubourg J-L, Pasteels J-M (1999) Decision-making in foraging by social insects. In: Detrain C, Deneubourg J-L, Pasteels J-M (eds) Information processing in social insects. Birkhäuser Verlag, Basel, pp 331–354Google Scholar
- Hölldobler B, Wilson EO (1990) The ants. Harvard University Press, CambridgeGoogle Scholar
- Lutz FE (1929) Observations on leaf-cutting ants. Am Mus Novit 388:1–21Google Scholar
- Pasteels J-M, Deneubourg J-L, Goss S (1987) From individual to collective behavior in social insects. Les Treilles Workshop, BaselGoogle Scholar
- Seeley TD (1995) The wisdom of the hive: the social physiology of honey bee. Harvard University Press, CambridgeGoogle Scholar
- Weber NA (1972) Gardening ants the attines. Memoirs of the American Philosophical Society, PhiladelphiaGoogle Scholar
- Wirth R, Herz H, Ryel RJ, Beyschlag W, Hölldobler B (2003) The herbivory of leaf-cutting ants. A case study on Atta colombica in the Tropical Rainforest of Panama. Ecological studies. Springer, HeidelbergGoogle Scholar