an alternative mating strategy is a strategy used by male or female animals, often with distinct phenotypes, that differs from the prevailing mating strategy of their sex. such strategies are diverse and variable both across and within species. animal sexual behaviour and mate choice directly affect social structure and relationships in many different mating systems, whether monogamous, polygamous, polyandrous, or polygynous. though males and females in a given population typically employ a predominant reproductive strategy based on the overarching mating system, individuals of the same sex often use different mating strategies. among some reptiles, frogs and fish, large males defend females, while small males may use sneaking tactics to mate without being noticed.