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

To test the relative importance of female choice, sneak copulation and male dominance as determinants of male mating success in a feral guppy populati on, we conducted a paired-male mating experiment using the colour patterns of male progeny to score paternity. Sneak copulation and male-male aggressi on had no noticeable effect on male mating success. Mating success was stro ngly related to the frequency of female behavioural responses to both displ aying and non-displaying males. Relative area of orange colouration and com plexity of male colour patterns were positively related to mating success. This substantiates the observed behavioural preference for orange, and stre ngthens claims that female choice is integral to male mating success. Males in trials in which both females failed to produce offspring showed lower l evels of black pigmentation, suggesting a threshold mating preference for t his 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 discusse d.