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Energetics of foraging and locomotion in the platypus Ornithorhynchus anatinus

Citation

Bethge, P and Munks, SA and Nicol, SC, Energetics of foraging and locomotion in the platypus Ornithorhynchus anatinus, Journal of Comparative Physiology B-Biochemical Systemic and Environmental Physiology, 171, (6) pp. 497-506. ISSN 0174-1578 (2001) [Refereed Article]

DOI: doi:10.1007/s003600100200

Abstract

We measured the energy requirements of platypuses foraging, diving and resting in a swim tank using flow-through respirometry. Also, walking metabolic rates were obtained from platypuses walking on a conventional treadmill. Energy requirements while foraging were found to depend on water temperature, body weight and dive duration and averaged 8.48 W kg-1. Rates for subsurface swimming averaged 6.71 W kg-1. Minimal cost of transport for subsurface swimming platypuses was 1.85 J N-1m-1 at a speed of 0.4 m s-1. Aerobic dive limit of the platypus amounted to 59 s. Metabolic rate of platypuses resting on the water surface was minimal with 3.91 W kg-1 while minimal RMR on land was 2.08 W kg-1. The metabolic rate for walking was 8.80 W kg-1 and 10.56 W kg-1 at speeds of 0.2 m s-1 and 0.3 m s-1, respectively. A formula was derived, which allows prediction of power requirements of platypuses in the wild from measurements of body weight, dive duration and water temperature. Platypuses were found to expend energy at only half the rate of semiaquatic eutherians of comparable body sizes during both walking and diving. However, costs of transport at optimal speed were in line with findings for eutherians. These patterns suggest that underwater locomotion of semiaquatic mammals have converged on very similar efficiencies despite differences in phylogeny and locomotor mode.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Physiology
Research Field:Comparative Physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Bethge, P (Mr Phillip Bethge)
Author:Munks, SA (Dr Sarah Munks)
Author:Nicol, SC (Associate Professor Stewart Nicol)
ID Code:22670
Year Published:2001
Web of Science® Times Cited:14
Deposited By:Anatomy and Physiology
Deposited On:2001-08-01
Last Modified:2011-08-03
Downloads:0

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