Body Girth as an Alternative to Body Mass for Establishing Condition Indexes in Field Studies: A Validation in the King Penguin

Vincent A. Viblanc*, Pierre Bize, Francois Criscuolo, Maryline Le Vaillant, Claire Saraux, Sylvia Pardonnet, Benoit Gineste, Marion Kauffmann, Onesime Prud'homme, Yves Handrich, Sylvie Massemin, Rene Groscolas, Jean-Patrice Robin

*Corresponding author for this work

Research output: Contribution to journalEditorial

11 Citations (Scopus)

Abstract

Body mass and body condition are often tightly linked to animal health and fitness in the wild and thus are key measures for ecophysiologists and behavioral ecologists. In some animals, such as large seabird species, obtaining indexes of structural size is relatively easy, whereas measuring body mass under specific field circumstances may be more of a challenge. Here, we suggest an alternative, easily measurable, and reliable surrogate of body mass in field studies, that is, body girth. Using 234 free-living king penguins (Aptenodytes patagonicus) at various stages of molt and breeding, we measured body girth under the flippers, body mass, and bill and flipper length. We found that body girth was strongly and positively related to body mass in both molting (R-2 = 0.91) and breeding (R-2 = 0.73) birds, with the mean error around our predictions being 6.4%. Body girth appeared to be a reliable proxy measure of body mass because the relationship did not vary according to year and experimenter, bird sex, or stage within breeding groups. Body girth was, however, a weak proxy of body mass in birds at the end of molt, probably because most of those birds had reached a critical depletion of energy stores. Body condition indexes established from ordinary least squares regressions of either body girth or body mass on structural size were highly correlated (r(s) = 0.91), suggesting that body girth was as good as body mass in establishing body condition indexes in king penguins. Body girth may prove a useful proxy to body mass for estimating body condition in field investigations and could likely provide similar information in other penguins and large animals that may be complicated to weigh in the wild.

Original languageEnglish
Pages (from-to)533-542
Number of pages10
JournalPhysiological and Biochemical Zoology
Volume85
Issue number5
Early online date7 Aug 2012
DOIs
Publication statusPublished - 2012

Keywords

  • APTENODYTES-PATAGONICUS
  • REPRODUCTIVE SUCCESS
  • GROUND-SQUIRRELS
  • LIFE-HISTORY
  • ENERGY
  • BIRDS
  • MOLT
  • RESIDUALS
  • DYNAMICS
  • EMPEROR

Cite this

Viblanc, V. A., Bize, P., Criscuolo, F., Le Vaillant, M., Saraux, C., Pardonnet, S., Gineste, B., Kauffmann, M., Prud'homme, O., Handrich, Y., Massemin, S., Groscolas, R., & Robin, J-P. (2012). Body Girth as an Alternative to Body Mass for Establishing Condition Indexes in Field Studies: A Validation in the King Penguin. Physiological and Biochemical Zoology, 85(5), 533-542. https://doi.org/10.1086/667540