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Energetics of Terrestrial Locomotion of the Platypus Ornithorhynchus Anatinus
Journal of Experimental Biology (2011)
  • Frank E. Fish, West Chester University of Pennsylvania
  • P B Frappell
  • R V Baudinette
  • P M MacFarlane

The platypus Ornithorhynchus anatinus Shaw displays specializations in its limb structure for swimming that could negatively affect its terrestrial locomotion. Platypuses walked on a treadmill at speeds of 0.19-1.08 m s(-1). Video recordings were used for gait analysis, and the metabolic rate of terrestrial locomotion was studied by measuring oxygen consumption. Platypuses used walking gaits (duty factor >0.50) with a sprawled stance. To limit any potential interference from the extensive webbing on the forefeet, platypuses walk on their knuckles. Metabolic rate increased linearly over a 2.4-fold range with increasing walking speed in a manner similar to that of terrestrial mammals, but was low as a result of the relatively low standard metabolic rate of this monotreme, The dimensionless cost of transport decreased with increasing speed to a minimum of 0.79, Compared with the cost of transport for swimming, the metabolic cost for terrestrial locomotion was 2.1 times greater. This difference suggests that the platypus may pay a price in terrestrial locomotion by being more aquatically adapted than other semi-aquatic or terrestrial mammals.

  • platypus; Ornithorhynchus anatinus; walking; energetics; cost of transport; gait; locomotion
Publication Date
February, 2011
Publisher Statement
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Citation Information
Frank E. Fish, P B Frappell, R V Baudinette and P M MacFarlane. "Energetics of Terrestrial Locomotion of the Platypus Ornithorhynchus Anatinus" Journal of Experimental Biology Vol. 204 Iss. 4 (2011)
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