Horn asymmetry and fitness in gemsbok, Oryx g. gazella

Abstract

The relationship between fluctuating asymmetry in horn of gemsbok (Oryx g. gazella) and a number of fitness component was determined in field study in Etosha National Park, Namibia. The length and width of horns and skull demonstrated fluctuating asymmetry. Both male and females with asymmetric horns were in poorer condition than asymmetric individuals. Individuals of both with symmetric horn more often won aggressive interactions at waterhole. Although symmetric individuals spent more time in dense vegetation, their vigilance rate was not higher than that of asymmetric individuals. Territorial, single male had more symmetric horns than males in herds, suggesting that mating success was inversely related to horn asymmetry. Females with symmetric horns more often had calves than asymmetry thus appears to reliably real phenotype quality as demonstrated by suite of fitness components.