Comparative Mortality Rates of Male and Female Kudus: The Costs of Sexual Size Dimorphism

The aim of this study was to document the difference in age-specific mortality rates of male and female kudus, and to relate this difference to possible causes, in particular the influence of sexual size dimorphism. The study was conducted over 10 years in the Kruger National Park, South Africa. Female survival was estimated by following cohorts of individually recognizable animals in closed social units. Male survival was estimated from year-class ratios, adjusted for population change. Male mortality rate remained similar to that of females up to 3 years of age. Thereafter, male mortality accelerated sharply with age. A male reaching full weight at 6 years of age had only a 0-5 chance of surviving a further year. Female mortality started rising only after 6 years of age