Understanding linkages between behaviors and mortality risk is critical for managing populations. Juveniles constitute a particularly vulnerable life stage, with growing evidence that within stages, individual strategies may be associated with greater predation risk and mortality. These forms of predator−prey dynamics are rarely explored in marine environments due to difficulties in confirming vital status of individuals, and the lack of data sets that link mortality to behavior. We analyzed 2 concurrently collected data sets for juvenile Steller sea lions Eumetopias jubatus in the Gulf of Alaska to examine associations between mortality and specific behavioral patterns. Forty-five juvenile Steller sea lions were instrumented with external satellite tags and internally implanted vital rate transmitters (LHX tags). From 2005 through 2018, 25 juveniles remained alive and 20 died (18 confirmed predation). Using a binomial generalized linear mixedeffects model, we tested whether the probability of individual mortality was associated with seasonally specific dive patterns (time wet, dive depth) or horizontal movement patterns (home range size, average trip distance). Additionally, in 3 cases, external tags were transmitting until death. To examine links between fine-scale ante-mortem behavioral patterns and predation susceptibility, we compared dive patterns recorded during the last 3 d of data transmissions (both for animals which survived and for those which died) to dive patterns recorded during other periods at sea. Results suggest individuals that spent more time dry or dove shallower had a greater mortality probability, which could reflect foraging tactics of predators. This study highlights the effectiveness of combining multiple telemetry systems for exploring the vulnerability of individuals to the consumptive effects of predators.

中文翻译：

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想死还是活：从潜水和太空使用模式中表征幼年虎海狮捕食的可能性

了解行为与死亡风险之间的联系对于管理人口至关重要。幼鱼是一个特别脆弱的生命阶段，越来越多的证据表明，在各个阶段，个体策略可能与更大的捕食风险和死亡率有关。由于难以确认个体的生命状态以及缺乏将死亡率与行为联系起来的数据集，这些形式的捕食者-猎物动态很少在海洋环境中进行探索。我们分析了 2 个同时收集的阿拉斯加湾幼年 Steller 海狮 Eumetopias jubatus 的数据集，以检查死亡率与特定行为模式之间的关联。45 只幼年 Steller 海狮配备了外部卫星标签和内部植入的生命率发射器（LHX 标签）。从 2005 年到 2018 年，25 只幼鱼还活着，20 只死亡（18 只被证实被捕食）。使用二项式广义线性混合效应模型，我们测试了个体死亡率的概率是否与季节性特定的潜水模式（潮湿时间、潜水深度）或水平移动模式（家庭范围大小、平均旅行距离）相关。此外，在 3 个案例中，外部标签一直传输到死亡。为了检查精细尺度的死前行为模式和捕食易感性之间的联系，我们比较了数据传输的最后 3 天记录的潜水模式（包括存活的动物和死亡的动物）与海上其他时期记录的潜水模式. 结果表明，干燥时间越长或潜水越浅的个体死亡率越高，这可能反映了捕食者的觅食策略。