Ornamental traits related to success in male-male competition were studied in red jungle fowl, Gallus gallus. In controlled fights between pairs of males, comb size was the only morphological trait that correlated with winning. Among free-ranging, socially integrated groups of 1-year-old males, body size and comb chroma (degree of saturation with pigment), in addition to comb size, were significantly related to dominance. In jungle fowl, the comb is strongly affected by blood testosterone level, which in turn reflects the current physical condition of the individual.
Bibliographical noteFunding Information:
This paper is dedicated to Professor Nicholas E. Collias for his pioneering work on the interrelationships between endocrine state, social organization and morphological traits in the domestic fowl, for his work on the behaviour and social organization of free-ranging red jungle fowl and for his interest and help with regard to our ongoing studies of sexual selection in the red jungle fowl. We thank C. Blanco-Montero, D. Keller, S. Ligon, N. W. Thornhill and P. Thornhill for their help with this project. A. Risser and the staff at San Diego Zoo generously supplied us with jungle fowl. Our research on red jungle supported by NSF Grant BSR-8515377.