, Volume 142, Issue 1, pp 127–135 | Cite as

Resource partitioning through oceanic segregation of foraging juvenile southern elephant seals (Mirounga leonina)

  • Iain C. FieldEmail author
  • Corey J. A. Bradshaw
  • Harry R. Burton
  • Michael D. Sumner
  • Mark A. Hindell
Behavioural Ecology


In highly dynamic and unpredictable environments such as the Southern Ocean, species that have evolved behaviors that reduce the effects of intra-specific competition may have a selective advantage. This is particularly true when juveniles face disadvantages when foraging due to morphological or physiological limitation, which is the case for many marine mammals. We tracked the at-sea movements of 48 juvenile southern elephant seals (Mirounga leonina) between the ages of 1 and 4 years from the population at Macquarie Island using locations derived from recorded light levels. There were significant differences in the total amount of the Southern Ocean covered by the different age-groups. The younger seals used a smaller area than the older seals. On average, the younger individuals also made more trips to sea than the older seals and did not travel as far on each trip. Females spent more time at sea than males and there were no significant differences between the total areas used by male and females. In summary, younger seals remained closer to the island at all times, and they spent more time in more northerly regions that older seals. These differences in behavior created temporal and spatial segregation between juveniles of different ages. Therefore, we suggest that these temporal and spatial separations help to avoid intra-specific competition for resources on land, space on beaches, and at-sea foraging areas. Such modifications of haul-out timing and behavior enable them to exploit a patchy and unpredictable environment.


Intra-specific competition Niche Ontogeny Phocid 



We thank members of the 51st–53rd Australian National Antarctic Research Expeditions (ANARE) to Macquarie Island for their assistance during fieldwork and the Australian Antarctic Division for logistic support, especially J. van den Hoff. M. Biuw, C. McMahon, J. van den Hoff, K. Wheatley and two anonymous reviewers provided useful comments on the manuscript. Data were collected with Australian Antarctic Animal Ethics Committee approval and Tasmanian Parks and Wildlife Service permits. Funding was provided by the Antarctic Science Advisory Committee and Sea World Research and Rescue Foundation.


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Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Iain C. Field
    • 1
    Email author
  • Corey J. A. Bradshaw
    • 1
    • 3
  • Harry R. Burton
    • 2
  • Michael D. Sumner
    • 1
    • 4
  • Mark A. Hindell
    • 1
  1. 1.Antarctic Wildlife Research UnitSchool of ZoologyHobartAustralia
  2. 2.Australian Antarctic DivisionKingstonAustralia
  3. 3.Key Centre for Tropical Wildlife ManagementCharles Darwin UniversityDarwinAustralia
  4. 4.Institute of Antarctic and Southern Ocean StudiesUniversity of TasmaniaHobartAustralia

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