Title

Testosterone Elevation and Response to Gonadotropin-Releasing Hormone Challenge by Male Northern Cardinals (Cardinalis cardinalis) Following Aggressive Behavior

Document Type

Article

Publication Date

6-1-2012

Department

Biological Sciences

Abstract

There is much discrepancy about the relationship between testosterone (T) and male aggressive behavior. For example, in birds, males of many species significantly elevate T levels during inter-male conflict. However, this is not universal, and in species where males typically do not elevate T during aggressive interactions, concentrations of the hormone are often assumed to be circulating at maximum levels. We examined if male northern cardinals (Cardinalis cardinalis) significantly elevated T during simulated territorial intrusions (STIs). We also examined if individuals had the capacity to further elevate T levels in response to gonadotropin-releasing hormone (GnRH) injections immediately after an aggressive encounter. Our results indicate that male cardinals do not significantly elevate T levels in response to 5115, but have the physiological capacity to significantly elevate T in response to GnRH injections following aggressive interactions. This implies that T levels of individuals captured during SIN were not at maximum concentrations. However, additional findings in this study also suggest the possibility that prolonged social instablity could elicit significant elevations in T in males of this species, warranting further investigation. (C) 2012 Elsevier Inc. All rights reserved.

Publication Title

Hormones and Behavior

Volume

62

Issue

1

First Page

99

Last Page

105