Stroke frequency, but not swimming speed, is related to body size in free-ranging seabirds, pinnipeds and cetaceans
Sato, Katsufumi; Watanuki, Yutaka; Takahashi, Akinori; Miller, Patrick J.O.; Tanaka, Hideji; Kawabe, Ryo; Ponganis, Paul J.; Handrich, Yves; Akamatsu, Tomonari; Watanabe, Yuuki; Mitani, Yoko; Costa, Daniel P.; Bost, Charles-Andre; Aoki, Kagari; Amano, Masao; Trathan, Phil; Shapiro, Ari; Naito, Yasuhiko. 2007 Stroke frequency, but not swimming speed, is related to body size in free-ranging seabirds, pinnipeds and cetaceans. Proceedings of the Royal Society of London, B, 274 (1609). 471-477. 10.1098/rspb.2006.0005Full text not available from this repository.
It is obvious, at least qualitatively, that small animals move their locomotory apparatus faster than large animals: small insects move their wings invisibly fast, while large birds flap their wings slowly. However, quantitative observations have been difficult to obtain from free-ranging swimming animals. We surveyed the swimming behaviour of animals ranging from 0.5kg seabirds to 30000kg sperm whales using animal-borne accelerometers. Dominant stroke cycle frequencies of swimming specialist seabirds and marine mammals were proportional to mass−0.29 (R2=0.99, n=17 groups), while propulsive swimming speeds of 1–2ms−1 were independent of body size. This scaling relationship, obtained from breath-hold divers expected to swim optimally to conserve oxygen, does not agree with recent theoretical predictions for optimal swimming. Seabirds that use their wings for both swimming and flying stroked at a lower frequency than other swimming specialists of the same size, suggesting a morphological trade-off with wing size and stroke frequency representing a compromise. In contrast, foot-propelled diving birds such as shags had similar stroke frequencies as other swimming specialists. These results suggest that muscle characteristics may constrain swimming during cruising travel, with convergence among diving specialists in the proportions and contraction rates of propulsive muscles.
|Programmes:||BAS Programmes > Global Science in the Antarctic Context (2005-2009) > DISCOVERY 2010 - Integrating Southern Ocean Ecosystems into the Earth System|
|Additional Keywords:||accelerometer, power spectral density, dive, free-ranging, scaling, optimal|
|NORA Subject Terms:||Zoology|
|Date made live:||12 Nov 2007 14:36|
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