smaller testes indicate less importance of sperm competition when considering mating strategies, and la plata dolphins generally have smaller testes. however, data reveals that the size of an individual's testes has seasonal variation which indicates their breeding season, but there is still research needed to further this observation. the size of la plata testes in relation to their body mass may reveal that they primarily perform serial monogamy. this does not directly indicate that la plata are purely monogamous, but that they may remain with one partner during a breeding season or a portion of that season.