Androgens and social status in female rock hyraxes

Abstract

Androgens have been linked to social behaviour in males across many vertebrate species. Despite the lack of gender specificity in steroid hormones, the association of androgens with behaviour in females remains obscure. We analysed steroid hormone levels in male and female rock hyraxes, Procavia capensis, and found strong ties between androgens and cortisol in females but not in males, despite the latter being the sex that usually shows this association. In the past we have shown that both female and male hyraxes have similar testosterone levels. In the present work, we found a significant interaction between testosterone levels and social status. Testosterone levels differed only between lower-ranking males and females, with females showing higher levels. Furthermore, dominant females had significantly lower testosterone levels than subordinate females. No association was detected between litter size and female rank, testosterone or cortisol levels. At this stage, we can only hypothesize that the assumed detrimental effects of high circulating androgen levels, reflected in the hair samples, influence the reproductive output or the offspring survival of subordinate females in some other ways, which require further investigation to be revealed.