Multiple benefits of multiple mating in guppies

The rewards of promiscuity for males are undisputed, But why should a femal e mate promiscuously, particularly when her partners offer no resources oth er than sperm and increase her chances of succumbing to predation or diseas e? This question has been hotly debated but at present remains largely unre solved [Jennions, M. D. & Petrie, M, (2000) Biol. Rev. 75, 21-64], One poss ibility is that females exploit postcopulatory mechanisms, such as sperm co mpetition, to increase both the quality and quantity of their offspring. In this paper, we use the Trinidadian guppy, a species with a resource-free m ating system, to test the hypothesis that females gain multiple benefits fr om multiple mating. Our results indicate that multiply mated females secure substantive advantages: They have shorter gestation times and larger brood s, and they produce offspring with better developed schooling abilities and escape responses than their singly mated counterparts.