This research project explores the interaction of hormones and the immune response in producing reproductive display behaviors and specialized morphology such as the rooster's bright red comb. Testosterone suppresses the immune response in many kinds of animals, and Dr. Zuk will examine how the immune system is affected by both natural and artificially-induced changes in the levels of this important hormone. After challenging male animals with a parasitic disease, their immune response will be monitored in the context of the degree of development of sexual characteristics and their effect on females. The research has implications for the study of the evolution of reproductive behavior because it may bring to light a new mechanism for that evolution.
