Group Size in Foraging African Penguins (Spheniscus demersus)

Authors

  • Rory P. Wilson,

    Corresponding author
    1. Percy FitzPatrick Institute of African Ornithology, and Department of Applied Mathematics, University of Cape Town, Rondebosch
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  • Marie-Pierre T. Wilson,

    1. Percy FitzPatrick Institute of African Ornithology, and Department of Applied Mathematics, University of Cape Town, Rondebosch
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  • Leslie McQuaid

    1. Percy FitzPatrick Institute of African Ornithology, and Department of Applied Mathematics, University of Cape Town, Rondebosch
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The Armada House, Weston, Towcester, Northants, NN12 8PU, England

Abstract

Diving synchrony was examined for varying group sizes of African penguins (Spheniscus demersus) travelling to their foraging grounds from their breeding islands. Groups of fewer than 12 birds always dived synchronously, whereas groups of more than 17 birds always dived asynchronously. Since travelling penguins do not dive deeply, large groups of birds can remain together irrespective of diving synchronization. Observations from boats showed that foraging penguins rarely occurred in groups of more than 17 birds. We suggest that groups of penguins that do not have synchronized dives cannot forage effectively, because foraging penguins dive deeply.

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