Diving behaviour of African penguins: do they differ from other Spheniscus penguins?

  • PG Ryan Department of Science and Technology/National Research Foundation Centre of Excellence at the Percy FitzPatrick Institute, University of Cape Town, Rondebosch 7701, South Africa
  • SL Petersen Escuela de Medicina Veterinaria, Universidad Andres Bello, Republica 440, Santiago, Chile
  • A Simeone Escuela de Medicina Veterinaria, Universidad Andres Bello, Republica 440, Santiago, Chile
  • D Grémillet Centre d’Ecologie de Physiologie Energétiques — Centre National de la Recherche Scientifique, 23 rue Becquerel, F-67087 Strasbourg, France
Keywords: African penguin, dive angle, dive depth, dive duration, logger impacts, <i>Spheniscus</i>

Abstract

African penguins Spheniscus demersus closely resemble Magellanic S. magellanicus and Humboldt S. humboldti penguins and have similar breeding and feeding ecologies. Adults feed on pelagic schooling fish in continental shelf waters, but African penguins have been reported to have shallower dive angles and remain submerged longer for dives to a given depth than their congeners. The few data for African penguins were gathered using relatively large time-depth recorders. We measured diving behaviour of 36 African penguins provisioning small chicks at three colonies near Cape Town, South Africa. Maximum and mean dive depths were 69m and 14m respectively. Diving took place mainly during the day. Although dive depths differed between colonies, there were no significant differences in dive duration or maximum, median or mean depth. Total dive duration, descent time, bottom time, ascent time and dive angle all were strongly correlated with the maximum depth attained. The diving behaviour of African penguins is similar to that of its congeners. Diving performance probably was compromised by the data-logger used in the previous study. Comparative data from Humboldt penguins also indicate potential biases in an earlier study of this species. Care is needed when comparing the diving performance of penguins measured using different loggers.

African Journal of Marine Science 2007, 29(2): 153–160
Published
2007-11-15
Section
Articles

Journal Identifiers


eISSN: 1814-2338
print ISSN: 1814-232X