Female competition and reproductive success in northern elephant seals

摘要: The probability of weaning a healthy pup increases with age in female northern elephant seals, Mirounga angustirostris. On Ano Nuevo Island, California, success among ‘prime’ females, those 6 years or older, was more than double that ‘young’ 3 to 5 old. Prime females were better mothers young because superior size, higher social dominance, and greater maternal experience; they likely mate high-ranking males gave birth at an optimal time place, circumstances maximized the their pups would survive, develop, reproduce. competitive advantage prime-age over younger ones greatest when density high. Young improved chances reproducing successfully by emigrating from crowded harems establishing new colonies.