Elephant seal female breeding histories at Año Nuevo

The elephant seal (Mirounga angustirostris) breeding colony at Año Nuevo, California, was founded in 1961, and since monitored closely until the present. Since 1968 a research group at the University of California, Santa Cruz, has studied it in detail. Individually identified females were monitored during the breeding season, and pupping records of many throughout their lifetimes were assembled. We address here the maximum reproductive success of females using the lifetime breeding histories. Females lived to a maximum of 23 years and were observed breeding in as many as 17 seasons. One female was observed with a pup nearby in 16 consecutive seasons, from age 4 through age 19. We compared females that gave birth to 10 or more pups (Supermoms) with females that bred at least once but produced fewer than 10 pups (Generic moms). Less than 17% of female weanlings bred at least once. Only 0.87% of females in the sample became Supermoms. We conclude that exceptional reproductive success in el...位于加利福尼亚州阿尼奥纽埃（Año Nuevo）的北象海豹（Mirounga angustirostris）繁殖种群，于1961年建立，此后一直受到严密监测直至今日。自1968年起，加州大学圣克鲁兹分校（University of California, Santa Cruz）的一个研究团队对其展开了细致研究。研究人员在繁殖季对个体可识别的雌性海豹进行监测，并收集了众多雌性个体终身的产仔记录。本研究基于雌性海豹的终身繁殖历史，探讨其最高繁殖成功率。雌性海豹的最长寿命为23年，观测到的繁殖季最多可达17个。有一只雌性海豹在4岁至19岁期间，连续16个繁殖季均在其附近诞下幼崽。研究团队将产下10只及以上幼崽的雌性（"超级妈妈（Supermoms）"）与至少繁殖过一次但产仔数不足10只的雌性（"普通妈妈（Generic moms）"）进行了对比。仅有不到17%的雌性断奶幼崽能够至少成功繁殖一次。样本中仅有0.87%的雌性个体成为"超级妈妈"。我们得出结论，雌性海豹的卓越繁殖成功率在……