Behavioral and physiological significance of minimum resting metabolic rate in king penguins.

Published

Journal Article

Because fasting king penguins (Aptenodytes patagonicus) need to conserve energy, it is possible that they exhibit particularly low metabolic rates during periods of rest. We investigated the behavioral and physiological aspects of periods of minimum metabolic rate in king penguins under different circumstances. Heart rate (f(H)) measurements were recorded to estimate rate of oxygen consumption during periods of rest. Furthermore, apparent respiratory sinus arrhythmia (RSA) was calculated from the f(H) data to determine probable breathing frequency in resting penguins. The most pertinent results were that minimum f(H) achieved (over 5 min) was higher during respirometry experiments in air than during periods ashore in the field; that minimum f(H) during respirometry experiments on water was similar to that while at sea; and that RSA was apparent in many of the f(H) traces during periods of minimum f(H) and provides accurate estimates of breathing rates of king penguins resting in specific situations in the field. Inferences made from the results include that king penguins do not have the capacity to reduce their metabolism to a particularly low level on land; that they can, however, achieve surprisingly low metabolic rates at sea while resting in cold water; and that during respirometry experiments king penguins are stressed to some degree, exhibiting an elevated metabolism even when resting.

Full Text

Duke Authors

Cited Authors

  • Halsey, LG; Butler, PJ; Fahlman, A; Woakes, AJ; Handrich, Y

Published Date

  • January 2008

Published In

Volume / Issue

  • 81 / 1

Start / End Page

  • 74 - 86

PubMed ID

  • 18040974

Pubmed Central ID

  • 18040974

Electronic International Standard Serial Number (EISSN)

  • 1537-5293

International Standard Serial Number (ISSN)

  • 1522-2152

Digital Object Identifier (DOI)

  • 10.1086/523318

Language

  • eng