Sperm have to fight when a female has multiple partners — which is pretty normal behavior in nearly all animals. Syracuse University researchers actually filmed the little sperm in action. By using fluorescent tagging technology, the scientists could watch the sperm compete in the female reproductive tract. The Scientist reports:. Watch Drosophila sperm fight.
This page has been archived and is no longer updated. Published online 29 July Nature doi Hannah Wunsch. What happens when sperm from two different males meet up? Is there all-out war, or do they live in harmony? Females in many animal groups have multiple mates - often close enough together in time to cause the sperm to mix.
Performed the experiments: SL. The authors confirm that all data underlying the findings are fully available without restriction. In species where females mate with multiple males, the sperm from these males must compete to fertilise available ova.
Sperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg  during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and variety of mates increases a female's chance to produce more viable offspring. Sperm competition is an evolutionary pressure on males, and has led to the development of adaptations to increase males' chance of reproductive success.