The Role of the Leopard Seal in the Tropho-Dynamics of the Antarctic Marine Ecosystem

  • D. B. Siniff
  • S. Stone

Summary

The Leopard Seal, Hydrurga leptonys, preys significantly on several species of vertebrates and invertebrates. Observations and specimens (stomach contents, reproductive tracts and skulls), collected during recent expeditions to the Antarctic, as well as data from past studies, provide insights into how this predator partitions pressure among trophic levels and species. These data and their analyses suggest hypotheses regarding the role of the Leopard Seal in influencing the Antarctic marine ecosystem. Variables, such as seasonal effects, sea-ice, and availability of prey species, cause changes in prey selection and influence predation rates. The impact that Leopard Seal predation has on the evolution of the life-history patterns of prey is considered, using data on observed foraging and escape behaviour. The seasonal distribution of prey items is hypothesized to influence the reproductive strategy of the Leopard Seal. Data from recent collections show that the breeding season of the Leopard Seal is much later in the austral summer than those of other Antarctic seals, and that delayed implantation probably does not exist in this species. The reason for these differences is hypothesized to be related to the ability of the Leopard Seal to utilize relatively many different prey species, resulting in a reproductive strategy that does not require the highly synchronized breeding and young-bearing periods characteristic of other seal species. Such considerations for the Leopard Seal are important in attempting to understand the dynamics of the Antarctic ecosystem, since this species may exert significant predatory pressure at several trophic levels.

Keywords

Biomass Formalin Migration Lactate Sonal 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1985

Authors and Affiliations

  • D. B. Siniff
  • S. Stone
    • 1
  1. 1.Department of Ecology and Behavioral BiologyUniversity of MinnesotaMinneapolisUSA

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