Insectes Sociaux

, Volume 58, Issue 3, pp 317–324 | Cite as

How much do army ants eat? On the prey intake of a neotropical top-predator

RESEARCH ARTICLE (C.W. Rettenmeyer memorial paper)


New World army ants (Ecitoninae) are nomadic group-predators that are widely thought to have a substantial impact on their prey. Nevertheless, quantitative data on prey intake by army ants is scarce and mostly limited to chance encounters. Here, I quantify the prey intake of the army ant Eciton hamatum at the contrasting scales of raid, colony (sum of simultaneous raids), and population. Like most army ants, E. hamatum conducts narrow ‘column raids’ and has a specialized diet of ant prey. I show that individual raids often had periods of no prey intake, and raid intake rates, calculated in g/min, differed significantly among colonies. Moreover, neither mean nor peak raid intake rates were correlated with colony size. Similarly, colony intake rates differed significantly among colonies, and mean colony intake rates were not correlated with colony size. However, mean colony intake rates were significantly higher than mean raid intake rates, and peak colony intake rate was correlated with colony size. Having multiple raids thus improves colony-level intake rates, and larger colonies can harvest more prey per unit time. Mean colony intake rate across colonies was 0.067 g/min dry weight and mean daily colony intake was calculated at 38.2 g. This intake is comparable to that of Eciton burchellii, which has a more generalized diet and conducts spectacular ‘swarm raids’ that are seen as having a greater impact on prey than column raids. Population size on Barro Colorado Island, Panama, was estimated to be 57 colonies, which extrapolates to a daily population intake of nearly 2 kg of prey dry weight, or 120 g/km2. Broadly, these findings demonstrate that column raiding army ants experience considerable variation in prey intake for individual raids, but can still achieve notable impact at the larger scales of colony and population. Furthermore, they challenge the idea that swarm-raiding species necessarily have greater intake and thus impact on prey. Instead, I suggest that conducting multiple column raids may be a strategy that allows for comparable intake from a more specialized diet.


Army ants Predation Diet Column raid Swarm raid Biomass 


  1. Belt T. 1874. The Naturalist in Nicaragua. John Murray, London. 442 ppGoogle Scholar
  2. Breton J.L., Dejean A., Snelling G. and Orivel J. 2007. Specialized predation on Wasmannia auropunctata by the army ant species Neivamyrmex compressinodis. J. Appl. Entomol. 131: 740–743Google Scholar
  3. Cherrett J.M. and Peregrine D.J. 1976. A review of the status of leaf-cutting ants and their control. Ann. Appl. Biol. 84: 124–128Google Scholar
  4. Cherrett J. 1986. The economic importance and control of leaf-cutting ants. In Economic Impact and Control of Social Insects (Vinson S.B., Ed) Praeger, New York. pp 165–192Google Scholar
  5. Darwin C. 1839. Journal of Researches into the Natural History and Geology of the Countries visited during the Voyage of the H. M. S. ‘Beagle’ round the World, under the Command of Capt. Fitz Roy, R. N. Henry Colburn, London. 551 ppGoogle Scholar
  6. Franks N.R. 1982a. A new method for censusing animal populations: the number of Eciton burchelli army ant colonies on Barro Colorado Island, Panama. Oecologia 52: 266–268Google Scholar
  7. Franks N.R. 1982b. Ecology and population regulation in the army ant Eciton burchelli. In: The Ecology of a Tropical Forest: Seasonal Rhythms and Long-Term Changes (Leigh E.G., Rand A.S. and Windsor D.M., Eds), Oxford University Press, Oxford. pp 389–395Google Scholar
  8. Franks N.R. 1985. Reproduction, foraging efficiency and worker polymorphism in army ants. In: Experimental Behavioral Ecology and Sociobiology: in Memoriam Karl von Frisch, 1886-1982 (Hölldobler B. and Lindauer M., Eds), Sinauer Associates, Sunderland Massachusetts. pp 91–107Google Scholar
  9. Franks N.R. 1980. The evolutionary ecology of the army ant Eciton burchelli on Barro Colorado Island, Panama. Ph.D. dissertation, The University of Leeds, Leeds, England. pp 242Google Scholar
  10. Franks N.R. and Bossert W.H. 1983. The influence of swarm raiding army ants on the patchiness and diversity of a tropical leaf litter ant community. In: Tropical Rain Forest: Ecology and Management. Special Publication of the British Ecological Society No. 2 (Sutton S.L., Whitmore T.C. and Chadwick A.C., Eds), Blackwell Scientific Publications, Oxford. pp 151–163Google Scholar
  11. Hölldobler B. and Wilson E.O. 1990. The Ants. Harvard University Press, Cambridge Massachusetts. pp. 752Google Scholar
  12. Kaspari M. and O’Donnell S. 2003. High rates of army ant raids in the Neotropics and implications for ant colony and community structure. Evol. Ecol. Res. 5: 933–939Google Scholar
  13. Lach L., Parr C.L. and Abbott K.L. 2010. Ant Ecology. Oxford University Press, Oxford. pp 432Google Scholar
  14. LaPolla J.S., Mueller U.G., Seid M. and Cover S.P. 2002. Predation by the army ant Neivamyrmex rugulosus on the fungus-growing ant Trachymyrmex arizonensis. Insect. Soc. 49: 251–256Google Scholar
  15. Leigh E.G. 1999. Tropical Forest Ecology: a View from Barro Colorado Island. Oxford University Press, USA. pp 264Google Scholar
  16. O’Donnell S., Lattke J., Powell S. and Kaspari M. 2007. Army ants in four forests: geographic variation in raid rates and species composition. J. Anim. Ecol. 76: 580–589Google Scholar
  17. Otis G.W., Santana C.E., Crawford D.L. and Higgins M.L. 1986. The effect of foraging army ants on leaf-litter arthropods. Biotropica 18: 56–61Google Scholar
  18. Powell S. and Clark E. 2004. Combat between large derived societies: a subterranean army ant established as a predator of mature leaf-cutting ant colonies. Insect. Soc. 51: 342–351Google Scholar
  19. Powell S. and Franks N.R. 2006. Ecology and the evolution of worker morphological diversity: a comparative analysis with Eciton army ants. Funct. Ecol. 20: 1105–1114Google Scholar
  20. Rettenmeyer C.W. 1963. Behavioral studies of army ants. Univ. Kans. Sci. Bull. 44: 281–465Google Scholar
  21. Rettenmeyer C.W., Chadab-Crepet R., Naumann M.G. and Morales L. 1983. Comparative foraging by neotropical army ants. In: Social Insects in the Tropics. Volume 2 (Jaisson P., Ed). Université Paris-Nord, Paris. pp 59–73Google Scholar
  22. Rico-Gray V. and Oliveira P.S. 2007. The Ecology and Evolution of Ant-Plant Interactions. University of Chicago Press, Chicago. 320 ppGoogle Scholar
  23. Schneirla T.C. 1971. Army Ants. A Study in Social Organization (Topoff H.R., Ed). W.H. Freeman and Co., San Francisco. pp 369Google Scholar
  24. Schneirla T.C. 1949. Army-ant life and behavior under dry-season conditions. 3. The course of reproduction and colony behavior. Bull. Am. Mus. Nat. His. 94: 3–81Google Scholar
  25. Schneirla T.C. 1955. The army ants. Rep. Smith. Inst. 1955: 379–406Google Scholar
  26. Swartz M.B. 1998. Predation on an Atta cephalotes colony by an army ant Nomamyrmex esenbecki. Biotropica 30: 682–684Google Scholar
  27. Teles Da Silva M. 1982. Behaviour of army ants Eciton burchelli and E. hamatum (Hymenoptera, Formicidae) in the Belem region III. Raid activity. Insect. Soc. 29: 243–267Google Scholar
  28. Vidal-Riggs J.M. and Chaves-Campos J. 2008. Method review: estimation of colony densities of the army ant Eciton burchellii in Costa Rica. Biotropica 40: 259–262Google Scholar
  29. Wetterer J.K., Gruner D.S. and Lopez J.E. 1998. Foraging and nesting ecology of Acromyrmex octospinosus (Hymenoptera: Formicidae) in a Costa Rican tropical dry forest. Fla. Entomol. 81: 61–67Google Scholar
  30. Wheeler G.C. and Wheeler J. 1976. Ant larvae: review and synthesis. Mem. Entomol. Soc. Wash. 7: 1–108Google Scholar
  31. Wheeler W.M. 1910. Ants: their Structure, Development and Behavior. The Columbia University Press, New York. pp 663Google Scholar

Copyright information

© International Union for the Study of Social Insects (IUSSI) 2011

Authors and Affiliations

  1. 1.Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonUSA
  2. 2.Smithsonian Tropical Research InstituteAnconRepublic of Panama

Personalised recommendations