Wolves are assumed to be ungulate obligates, however, a recently described pack on Pleasant Island, Alaska USA, is persisting on sea otters and other marine resources without ungulate prey, violating this long‐held assumption. We address questions about these wolves regarding their origin and fate, degree of isolation, risk of inbreeding depression, and diet specialization by individual and sex. We applied DNA metabarcoding and genotyping by amplicon sequencing using 957 scats collected from 2016 to 2022, and reduced representation sequencing of tissue samples to establish a detailed understanding of Pleasant Island wolf ecology and compare them with adjacent mainland wolves. Dietary overlap was higher among individual wolves on Pleasant Island (Pianka's index mean 0.95 ± 0.03) compared to mainland wolves (0.70 ± 0.21). The individual diets of island wolves were dominated by sea otter, ranging from 40.6% to 63.2% weighted percent of occurrence (wPOO) (mean 55.5 ± 8.7). In contrast, individual mainland wolves primarily fed on ungulates (42.2 ± 21.3) or voles during a population outbreak (31.2 ± 23.2). We traced the origin of the Pleasant Island pack to a mainland pair that colonized around 2013 and produced several litters. After this breeding pair was killed, their female offspring and an immigrant male became the new breeders in 2019. We detected 20 individuals of which 8 (40%) were trapped and killed while two died of natural causes during the 6‐year study. Except for the new breeding male, the pedigree analysis and genotype results showed no additional movement to or from the island, indicating limited dispersal but no evidence of inbreeding. Our findings suggest wolves exhibit more flexible foraging behavior than previously believed, and hunting strategies can substantially differ between individuals within or between packs. Nevertheless, anthropogenic and natural mortality combined with limited connectivity to the mainland may inhibit the continued persistence of Pleasant Island wolves.

中文翻译：

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鹿灭绝后岛屿狼的起源、连通性和个体特化

狼被认为是有蹄类动物，然而，最近描述的美国阿拉斯加州普莱森特岛的狼群却坚持以海獭和其他海洋资源为食，而没有有蹄类动物的猎物，这违反了这一长期以来的假设。我们解决了有关这些狼的问题，包括它们的起源和命运、孤立程度、近亲繁殖抑郁症的风险以及个体和性别的饮食专门化。我们利用 2016 年至 2022 年收集的 957 个粪便应用 DNA 元条形码和扩增子测序进行基因分型，并对组织样本进行简化代表性测序，以建立对普莱森特岛狼生态的详细了解，并将其与邻近的大陆狼进行比较。与大陆狼 (0.70 ± 0.21) 相比，普莱森特岛上的狼个体的饮食重叠度更高 (Pianka 指数平均值为 0.95 ± 0.03)。岛屿狼的个体饮食以海獭为主，加权出现率 (wPOO) 范围为 40.6% 至 63.2%（平均值 55.5 ± 8.7）。相比之下，在种群爆发期间，个别大陆狼主要以有蹄类动物（42.2±21.3）或田鼠为食（31.2±23.2）。我们将普莱森特岛狼群的起源追溯到一对大陆狼群，它们在 2013 年左右定居并产下了几窝幼崽。在这对繁殖对被杀死后，它们的雌性后代和一只移民雄性成为了 2019 年的新繁殖者。在为期 6 年的研究中，我们发现了 20 只个体，其中 8 只（40%）被困并死亡，另外 2 只自然死亡。除了新繁殖的雄性外，谱系分析和基因型结果显示没有额外的进出该岛的活动，表明扩散有限，但没有近亲繁殖的证据。我们的研究结果表明，狼表现出比之前认为的更灵活的觅食行为，并且狼群内或狼群之间的个体之间的狩猎策略可能存在很大差异。然而，人为和自然死亡加上与大陆的有限联系可能会抑制普莱森特岛狼的持续存在。