Intersexual and intrasexual selection, sneak copulation and male ornamentation in guppies (Poecilia reticulata)

Abstract

To test the relative importance of female choice, sneak copulation and male dominance as determinants of male mating success in a feral guppy population, we conducted a paired-male mating experiment using the colour patterns of male progeny to score paternity. Sneak copulation and male-male aggression had no noticeable effect on male mating success. Mating success was strongly related to the frequency of female behavioural responses to both displaying and non-displaying males. Relative area of orange colouration and complexity of male colour patterns were positively related to mating success. This substantiates the observed behavioural preference for orange, and strengthens claims that female choice is integral to male mating success. Males in trials in which both females failed to produce offspring showed lower levels of black pigmentation, suggesting a threshold mating preference for this ornament despite it not being correlated with variation in male mating success or attractiveness measures. The implications of these findings for the evolution of multiple secondary sex traits in male guppies are discussed.