The porpoising of penguins: an energy-conserving behavior for respiratory ventilation?
The leaps of porpoising captive Humboldt (Spheniscus humboldti) and blackfoot (Spheniscus demersus) and free-ranging Adelie (Pygoscelis adeliae) penguins were analyzed from film. Captive and free-ranging penguins leap with a mean (±SD) emergence angle of 32°(±5°), significantly different from the 45...
| Published in: | Canadian Journal of Zoology |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1987
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/z87-031 http://www.nrcresearchpress.com/doi/pdf/10.1139/z87-031 |
| Summary: | The leaps of porpoising captive Humboldt (Spheniscus humboldti) and blackfoot (Spheniscus demersus) and free-ranging Adelie (Pygoscelis adeliae) penguins were analyzed from film. Captive and free-ranging penguins leap with a mean (±SD) emergence angle of 32°(±5°), significantly different from the 45° angle assumed by some hydromechanical models. Captive bird leaps occurred over a maximum of 22% of the total distance travelled, making energy savings marginal. Although physically able to leap at 2.3 m s −1 , captive birds showed a minimum swimming speed of 3 m s −1 for the onset of leaping behavior, providing minimum in-air time comparable to the measured respiratory inhalation time. Porpoising may minimize energy expended for ventilation. |
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