On penguin porpoising

• Published in: Canadian Journal of Zoology
• Main Authors: Blake, R. W., Smith, M. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1988
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Aptenodytes forsteri
• Online Access: http://dx.doi.org/10.1139/z88-310; http://www.nrcresearchpress.com/doi/pdf/10.1139/z88-310

Speeds above which porpoising becomes energetically more economical than swimming are calculated from a hydro-mechanical model for Humboldt (Spheniscus humboldti) and emperor (Aptenodytes forsteri) penguins. Predicted minimum porpoising speeds for S. humboldti are significantly less than observed values. At low porpoising speeds time in air is low and may not be sufficient to permit efficient breathing. It is suggested that ventilatory requirements may set a practicable lower bound on porpoising speed. Other possible constraints on the lower limits to porpoising speed include the requirement of raising the centre of mass high enough for the animal to completely clear the surface and the influence of sea conditions.