Security, size, or sociality: what makes markhor (Capra falconeri) sexually segregate?

Abstract

Sexual segregation, the tendency to seasonally live in groups comprised of separate sexes, is widespread in sexually dimorphic polygynous ungulates. The causes for such segregation are still being studied and debated to arrive at a universal explanation. We assessed sexual segregation in the markhor, Capra falconeri—a dimorphic mountain ungulate inhabiting a seasonal temperate environment. We observed markhor herd composition, gender-specific diet, and habitat use over 3 years and multiple seasons. We tested the predictions of the Reproductive Strategy-Predation Risk Hypothesis (RSH) that focuses on offspring security, and the Forage Selection-Sexual Dimorphism Hypothesis (FSH) based on different foraging needs between the sexes due to size dimorphism. Generalized linear models were used to identify the important variables that best explained segregation in markhor. Male and female markhor showed a tendency to segregate throughout the year outside the mating season. Female markhor were confined to cliffs with relatively less forage cover, whereas males used areas with relatively better forage away from the security of cliffs. Females also occurred at lower elevations compared to males. Social segregation prevailed during pre-parturition and continued until autumn when the offspring were older, indicating a role of other factors besides predation risk. Sexual segregation in markhor was influenced by multiple mechanisms.