The effects of female choice and male-male competition on the mating success of male guppies

Abstract

This study examined the effects of female choice and male-male competition on male mating success in the guppy, Poecilia reticulata. The fraction of a male's displays that elicited a sexual response from a female was used as a measure of relative female preference for that male. Male mating success was measured by scoring paternity of sons, using colour pattern as a genetic marker. Female preference had a significant effect on male mating success. Male-male competition was relatively uncommon, and did not involve direct threats or combat. Data on male-male competition did not significantly predict mating success. Males from different experimental groups with the same colour pattern had similar mating success. This suggests that female choice could have been based on colour pattern. However, there was no obvious relationship of particular colour pattern elements to mating success or female preference. The males with the same colour pattern were related and most were reared together, so other genetic or environmental factors could have led to similar mating success.