Relatedness and site fidelity at the southern elephant seal, Mirounga leonina, breeding colony in the Falkland Islands

Southern elephant seals are highly gregarious during the breeding season, and both sexes show fidelity to the colony. We used microsatellite DNA analysis to assess kinship among seals in the main colony on the Falkland Islands. Specifically, we investigated whether females tend to cluster with close kin and avoid mating with male kin. We also tested expectations for kinship patterns based on sex differences in site fidelity and philopatry. Relatedness within a harem was significantly greater than between harems for only two of seven harems and was not related to harem size. Some long-term associations of female kin were found within harems, including associations of up to 5 years, but kinship among these females was not significantly higher on average than among dyads of other returning females. There was no pattern suggesting that females tended to choose harems with harem holders that were either more or less related to them than alternative harem holders. Overall, pairwise comparisons of females showed significantly greater kinship than pairwise comparisons of males, consistent with previous studies suggesting greater male dispersal.