Morphological variation in the Common Fiscal Lanius collaris along an altitudinal gradient in southern Africa

  • S Soobramoney School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa
  • CT Downs School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa
  • NJ Adams School of Life and Environmental Sciences, University of KwaZulu-Natal, Private Bag X10, Dalbridge, Durban 4014, South Africa; Current address: Faculty of Health and Environmental Sciences, UNITEC Institute of Technology, Private Bag 92025, Auckland, New

Abstract

Geographic variation among four Common Fiscal subpopulations along an altitudinal gradient in South Africa demonstrated significant variation of 13 morphological features and 38 skeletal characters. Common Fiscals were largest in cooler, less humid, more arid areas and smallest in warmer, wetter, more humid localities, supporting Bergmann's Rule. Patterns of variation in morphology, anatomy and skeletal trends were significantly correlated with 11 climatic trends. Cardiopulmonary organ mass and blood haematocrit increased with altitude and reflected adaptations to low ambient temperatures and decreased oxygen pressures associated with high altitudes. These trends are concordant with those reported in various other avian species.

Ostrich 2005, 76(3&4): 130–141
Published
2005-10-20
Section
Articles

Journal Identifiers


eISSN: 1727-947X
print ISSN: 0030-6525