High male reproductive success in a low-density Antarctic fur seal (Arctocephalus gazella) breeding colony

TitleHigh male reproductive success in a low-density Antarctic fur seal (Arctocephalus gazella) breeding colony
Publication TypeJournal Article
Year of Publication2014
AuthorsBonin C.A, Goebel M.E, Hoffman J.I, Burton RS
JournalBehavioral Ecology and Sociobiology
Date Published2014/04
Type of ArticleArticle
ISBN Number0340-5443
Accession NumberWOS:000332979400007
KeywordsBreeding; elephant seals; mating system; mating systems; Microsatellite; microsatellite markers; multilocus genotype data; Paternity; pinniped; population-growth; Relatedness; Reproductive skew; Seal; sexual selection; sibship inference; Site fidelity; south shetland

Understanding how population density influences mating systems may lead to important insights into the plasticity of breeding behavior, but few natural systems allow for such studies. Antarctic fur seals (Arctocephalus gazella) provide an interesting model system because they breed in colonies of varying densities. Previous studies have largely focused on a high-density site at Bird Island, South Georgia. Here, 13 highly polymorphic microsatellite loci were used to conduct a genetic analysis of a low-density breeding colony of this species at Livingston Island, approximately 1,600 km south of South Georgia. The majority of adults seen ashore (n = 54) were sampled together with every pup born (n = 97) over four consecutive years. Paternities were confidently assigned for 34 out of the 97 pups. Two out of 23 sampled males accounted for the paternity of 28 % of all pups sampled during the study and 82 % of the pups with an assigned father. Moreover, a full likelihood pedigree inference method assigned a further eight paternities to a single unsampled male seal that is inferred to have held a territory during the season before the study began. The most successful males in our study easily surpassed the previous record for the total number of pups sired per male seal for the species. Furthermore, we identified two triads of full siblings implying that their parents remated in three consecutive years. These findings suggest that territorial male fur seals may achieve greater success in monopolizing access to breeding females when population density is relatively low.

Short TitleBehav. Ecol. Sociobiol.
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