Morphology-based tool for sexing White-backed Vultures in the field

Abstract

We explored the reliability of sex determination based on morphometric measurements in African White-backed Vultures (Gyps africanus), a species that has been known to lack sexual dimorphism. Examining 61 adults, we measured 13 morphologic traits and determined the sex using DNA from blood. Applying Linear Discriminant Analysis, we identified a combination of head width, body mass and bill depth to be a robust indicator for sex. Based on this finding we developed a practical equation for efficient sex determination in the field.