Meeting Abstract

59.11  Wednesday, Jan. 6  Flexibility of the HPG Axis of Female Northern Cardinals (Cardinalis cardinalis): Implications for Behavior and Reproductive Context DEVRIES, M. S.*; HOLBROOK, A. L.; WINTERS, C. P.; JAWOR, J. M.; The University of Southern Mississippi; The University of Southern Mississippi; The University of Southern Mississippi; The University of Southern Mississippi Margaret.DeVries@usm.edu

Testosterone’s influence on aggression and parental care has been well studied in male birds, but the relationship between testosterone (T) and female behavior is poorly resolved. The impact of elevated T on female aggression and parental care varies among species and recent evidence suggests that T elevations influencing female behavior could depend upon social context and/or reproductive stage. Using gonadotropin-releasing hormone (GnRH) challenges and simulated nest intrusions (SNIs), we examined the flexibility of the hypothalamic-pituitary-gonadal (HPG) axis of female Northern Cardinals (Cardinalis cardinalis) across multiple reproductive periods. Results indicate that female cardinals have the capacity to elevate T before the onset of breeding (via GnRH challenge) and in response to intrasexual intruders at the nest during incubation (SNI). Testosterone levels induced by GnRH challenges did not significantly differ from natural increases in T produced in response to SNIs. However, our findings suggest that the HPG axis of female cardinals is relatively inflexible while females are providing nestling care (e.g., feeding). These results imply that while elevated T might support female aggression in this species, the responsiveness of the HPG axis of female cardinals could be dependent on reproductive context.