acta ethologica

, Volume 5, Issue 2, pp 95–99

Red kangaroos (Macropus rufus) receive an antipredator benefit from aggregation

Original Article

DOI: 10.1007/s10211-002-0070-5

Cite this article as:
Blumstein, D.T. & Daniel, J.C. acta ethol (2003) 5: 95. doi:10.1007/s10211-002-0070-5

Abstract

For species that cannot seek cover to escape predators, aggregation becomes an important strategy to reduce predation risk. However, aggregation may not be entirely beneficial because aggregated animals may compete for access to limited resources and might even attract predators. Available evidence suggests that foraging competition influences time allocation in large-bodied macropodid marsupials, but previous studies have focused primarily on species in areas with protective cover. We studied red kangaroos, a species often found in open country without noticeable cover, to determine whether they experienced a net benefit by aggregation. Red kangaroos varied their time allocation as a function of group size and, importantly, more variation in time allocation to vigilance and foraging was explained by non-linear models than by linear models. This suggests red kangaroos directly translated the reduction of predation risk brought about by aggregation into greater time foraging and less time engaged in vigilance. We infer that red kangaroos received a net benefit by aggregation. Social species living in the open may be generally expected to rely on others to help manage predation risk.

Keywords

Antipredator behaviorBenefits and costs of socialityGroup-size effectsRed kangaroo

Copyright information

© Springer-Verlag and ISPA 2003

Authors and Affiliations

  1. 1.Department of Organismic Biology, Ecology and EvolutionUniversity of CaliforniaLos AngelesUSA
  2. 2.The Cooperative Research Centre for the Conservation and Management of MarsupialsMacquarie UniversitySydneyAustralia