A condition index for African penguin Spheniscus demersus chicks

  • A Lubbe
  • LG Underhill
  • LJ Waller
  • J Veen

Abstract

The body condition of altricial seabird chicks is directly related to the amount of food received from their parents, which depends on feeding conditions at sea. An index of body condition is therefore a useful tool for assessing variation in food availability between different breeding colonies. Quantile regression techniques were used to develop a body condition index for African penguin Spheniscus demersus chicks, based on maximum and minimum growth relative to structural size. This is considered the most appropriate index for comparing the body condition of groups of chicks, varying in size and of unknown age, between breeding colonies. Based on this study, recommendations are made with regard to morphometric measurements, sample size and the sampling interval required to compare effectively the condition of African penguin chicks between breeding colonies throughout their distributional range.

Keywords: African penguin chick, body condition, food availability, quantile regression

African Journal of Marine Science 2014, 36(2): 143–154

Author Biographies

A Lubbe
Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa
LG Underhill
Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa; Marine Research Institute, University of Cape Town, Rondebosch, South Africa
LJ Waller
Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa; Marine Research Institute, University of Cape Town, Rondebosch, South Africa; Western Cape Nature Conservation Board, Scientific Services, Hermanus, South Africa
J Veen
VEDA Consultancy, Wenum Wiesel, The Netherlands
Published
2014-07-29
Section
Articles

Journal Identifiers


eISSN: 1814-2338
print ISSN: 1814-232X