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.长寿命脊椎动物的种群动态极大程度依赖于成体存活率，但针对诸多长寿命哺乳动物类群，影响其成体存活率的因素，以及成体存活率与其他生命率之间的协变异关系，目前尚未得到充分探究。例如，在34种现存鳍足类（pinniped）中，仅有9种通过纵向数据开展了种群衰老（actuarial senescence）相关研究。本研究采用标记重捕模型（mark-recapture models），基于阿拉斯加东南部（SEAK）5个繁殖群中4个位点上完成个体标记的2795头北海狮（Eumetopias jubatus）幼崽的22年重目击数据，对这种长寿命、性二型鳍足类的衰老特征、年度变异及生活史特征（life-history traits）间的协变异关系展开研究。不同性别个体的衰老起始年龄存在差异（雌性约16~17岁，雄性约8~9岁），但衰老速率无显著差异（雌性的衰老速率为每年-0.047，雄性为每年-0.046）。SEAK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范围约为±0.10。研究观测到雄性存活率与繁殖成功率之间存在正协变异关系。具有领域的雄性个体存活率较非领域雄性高0.20，这使得高龄存活个体中的绝大多数均为领域雄性。