FASHION AND AGE IN PHEASANTS - AGE-DIFFERENCES IN MATE CHOICE

Commonly, younger males have less exaggerated secondary sexual charact ers than older males. In recent models of the evolution of ornamental traits through intersexual selection, it is often assumed that the orn aments confer a handicap to the bearers and thus reflect males' phenot ypic condition. Hence, if younger males have a lower cost in growing t heir less exaggerated ornaments because of delayed development, it cou ld be expected that those traits should be less revealing of condition in younger individuals. Consequently, in species where the developmen t of ornaments is age dependent, females should pay less attention to condition-dependent traits when choosing among younger as compared wit h older males. This study on ring-necked pheasants shows that males' a ttraction of females, measured in the wild by radio-tracking, was less affected by spur length in 1-year-old males than in older males. In a ddition, analysis of fluctuating asymmetry suggests that the shorter s purs of 1-year-old pheasants were less revealing of male quality.