Life-history and hormonal control of aggression in black redstarts: Blocking testosterone does not decrease territorial aggression, but changes the emphasis of vocal behaviours during simulated territorial intrusions

摘要: Introduction: Many studies in behavioural endocrinology attempt to link territorial aggression with testosterone, but the exact relationship between testosterone and behaviour is still unclear may depend on ecology of a species. The degree which facilitates particularly little understood species that defend territories during breeding outside season, when plasma levels are low. Here we suggest contexts other than reproduction have lost direct regulation by androgens even season. In such species, only those components territoriality function simultaneously as sexually selected signals be under control sex steroids. Results: We investigated black redstarts (Phoenicurus ochruros), shows periods within treated males an anti-androgen aromatase inhibitor season block both indirect effects testosterone. Three ten days after treatment, implanted were challenged simulated intrusion. treatment did not reduce overall response, it changed emphasis territoriality: experimental invested more behaviours addressed directly towards intruder, whereas placebo-treated put most effort into their vocal component primarily directed mating partner rather male opponent. Conclusions: combination previous findings, these data decoupled from redstarts. However, high facilitatecontext dependent changes song.