Abstract
It has been predicted that geometrically similar animals would swim at the same speed with stroke frequency scaling with mass-1/3. In the present study, morphological and behavioural data obtained from free-ranging penguins (seven species) were compared. Morphological measurements support the geometrical similarity. However, cruising speeds of 1.8-2.3m s-1 were significantly related to mass0.08 and stroke frequencies were proportional to mass-0.29. These scaling relationships do not agree with the previous predictions for geometrically similar animals. We propose a theoretical model, considering metabolic cost, work against mechanical forces (drag and buoyancy), pitch angle and dive depth. This new model predicts that: (i) the optimal swim speed, which minimizes the energy cost of transport, is proportional to (basal metabolic rate/drag)1/3 independent of buoyancy, pitch angle and dive depth; (ii) the optimal speed is related to mass0.05; and (iii) stroke frequency is proportional to mass -0.28. The observed scaling relationships of penguins support these predictions, which suggest that breath-hold divers swam optimally to minimize the cost of transport, including mechanical and metabolic energy during dive.
Original language | English |
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Pages (from-to) | 707-714 |
Number of pages | 8 |
Journal | Proceedings of the Royal Society B: Biological Sciences |
Volume | 277 |
Issue number | 1682 |
DOIs | |
Publication status | Published - 2010 Mar 7 |
Externally published | Yes |
Keywords
- Accelerometer
- Buoyancy
- Energy
- Free ranging
- Isometric model
- Morphology
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Immunology and Microbiology(all)
- Environmental Science(all)
- Agricultural and Biological Sciences(all)