Paternity and Mating Success in Elephant Seals The aim of this study is to determine the relationship between mating behavior of males and paternity in the most highly polygamous animals in nature, the elephant seals, Mirounga angustirostris and M. leonina. Male seals that aggressively dominate other males monopolize mating with hundreds of females grouped in harems but the degree to which mating success converts to paternity is unknown in this and other highly polygamous species. Mating records of individually marked seals at Ano Nuevo, California, and Peninsula Valdes, Chubut, Argentina, will be obtained to determine mating success. Small tissue samples will be collected from males, females and their pups, and paternity will be determined using DNA analysis (microsatellite variation). Paternal analysis is a more accurate measure of male reproductive success than mating success. It is important to measure individual reproductive success because it estimates the degree to which one or a few individuals determine the genetic composition of the next generation, that is, the speed and direction of evolutionary change. Estimates of differential reproductive success between the sexes explain sex differences in morphology, behavior, and life history strategies.
