Summary: Mateos (2005)

In vertebrates, the relationship between glucocorticoids, testosterone, social and sexual behaviours is often complicated and incompletely understood. The subordination stress paradigm predicts that subordinate individuals should show higher levels of glucocorticoids, dominants should have higher levels of testosterone and there should be an inverse relationship between glucocorticoid concentration and testosterone. Mateos (2005) studied male ring-necked  pheasants, Phasianus colchicus, and found that dominants and  high-displaying males had higher levels of testosterone, but, in contrast to expectations, also had higher levels of corticosterone. This indicates a positive correlation between testosterone and glucocorticoids. She suggests that the results support a stress-mediated version of the immunocompetence handicap hypothesis.