Morphometric characteristic of bird eggs of different developmental modes

The variability of length, diameter and shape indexes of eggs was investigated in a wide range of altricial-precocial spectrum of birds. Birds with different developmental modes significantly differ by length, diameter and shape indexes of eggs. Length and diameter of eggs were the main discriminating factors. Indexes of cloacal and infundibular zones of eggs were the main discriminating factors between bird orders. The more complete description of the egg shape should contain besides the elongation indexes the values of the radii of the egg surface. Because the phylogeny significantly influences the size and shape of birds' eggs the morphometric parameters of the eggs can be used as additional criteria in the investigation of avian evolution and systematics.