Meeting Abstract
Across vertebrates, testosterone (T) is considered a key player in the hormonal regulation of territorial aggression. While aggression is widespread in both males and females, endocrine regulation of aggression may be divergent between the sexes. In particular, empirical and theoretical research suggests that high levels of circulating T may not explain behavioral variation in female aggression, potentially because high T can interfere with maternal care. For species in which males conduct parental care and females aggressively defend territories (i.e. sex-role reversed), these constraints may not be as relevant, but empirical tests comparing T and aggression within and between sexes in sex-role reversed species are rare. We examined this question in sex-role reversed male and female Northern Jacanas (Jacana spinosa) in Panama. We simulated territorial intrusion to measure aggression and are currently measuring circulating T levels in both sexes. Results will speak to the generality of the hypothesis that T levels are constrained by parental care, lending insight into the similarities and differences in endocrine mechanisms of aggression in males and females.
