Data from: Survival of adult Steller sea lions in Alaska: senescence, annual variation and covariation with male reproductive success

Population dynamics of long-lived vertebrates depend critically on adult survival, yet factors affecting survival and covariation between survival and other vital rates in adults remain poorly examined for many taxonomic groups of long-lived mammals (e.g. actuarial senescence has been examined for only 9 of 34 extant pinniped species using longitudinal data). We used mark-recapture models and data from 2,795 Steller sea lion (Eumetopias jubatus) pups individually-marked at 4 of 5 rookeries in southeastern Alaska (SEAK) and resighted for 22 years to examine senescence, annual variability, and covariation among life-history traits in this long-lived, sexually-dimorphic pinniped. Sexes differed in age of onset (~16–17 and ~8-9 years for females and males, respectively), but not rate (-0.047 and -0.046/year of age for females and males) of senescence. Survival of adult males from northern SEAK had greatest annual variability (~±0.30 among years), whereas survival of adult females ranged ~±0.10 annually. Positive covariation between male survival and reproductive success was observed. Survival of territorial males was 0.20 higher than that of non-territorial males, resulting in the majority of males alive at oldest ages being territorial.长寿脊椎动物的种群动态高度依赖于成体存活率，但针对诸多长寿哺乳动物类群，影响成体存活率的因素以及存活率与其他生命率的协变关系仍未得到充分研究。例如，现有34种现存鳍足类（pinniped）动物中，仅9种通过纵向数据开展了死亡衰老（actuarial senescence）相关研究。本研究采用标记-重捕模型（mark-recapture models），结合阿拉斯加东南部（SEAK）5个繁殖地中4个的2795只北海狮（Steller sea lion, Eumetopias jubatus）幼崽个体标记数据，通过22年的重捕记录，对这种长寿且具有性二态性的鳍足类动物的衰老、年度存活率变异以及生活史特征间的协变关系展开研究。结果显示，两性的衰老起始年龄存在差异（雌性约16~17岁，雄性约8~9岁），但衰老速率无显著区别（雌性与雄性的衰老速率分别为-0.047和-0.046/岁）。阿拉斯加东南部北部区域的成年雄性存活率年度变异幅度最大（年间波动约±0.30），而成年雌性存活率的年度波动幅度约为±0.10。研究发现雄性存活率与繁殖成功率之间存在正协变关系。领域性雄性的存活率较非领域性雄性高出0.20，这使得高龄存活个体中绝大多数为领域性雄性。