The role of androgen receptors in regulating territorial aggression in male song sparrows.

摘要: This paper examines the role that androgen receptors (ARs) play in modulating aggressive behavior male song sparrows, Melospiza melodia morphna. Song sparrows are seasonally breeding, territorial birds maintain year-round territories with male-female pair bonds formed during spring breeding season. Plasma testosterone levels peak as established and mates acquired. In late summer, fall remain basal non-breeding We examined of ARs regulating aggression captive under short- long-day conditions well just prior to, at start breading season freely living using nonsteroidal antiandrogen flutamide to block AR function. Birds were implanted either empty or drug filled silastic implants for 18 42 days then challenged a novel decoy assess individual level male-male aggression. Freely remained on their home territory underwent simulated intrusion, whereas laboratory-held assessed laboratory intrusion cage. Experimental treatment decreased pre-breeding life history substage (March-April) (16L:8D) conditions. During early (April-May) there was no measurable effect behavior, nor difference (8L:16D) birds. demonstrates an important component neuroendocrine control behavior. Given only affected LD birds, results suggest dependent changes sparrow states change.