Dataset S8 from Foraging history of individual elephants using DNA metabarcoding

Individual animals should adjust diets according to food availability. We used DNA metabarcoding to construct individual-level dietary timeseries for elephants from two family groups in Kenya varying in habitat use, social position and reproductive status. We detected at least 367 dietary plant taxa, with up to 137 unique plant sequences in one fecal sample. Results matched well-established trends: elephants tended to eat more grass when it rained and other plants when dry. Nested within these switches from ‘grazing’ to ‘browsing’ strategies, dietary DNA revealed seasonal shifts in food richness, composition and overlap between individuals. Elephants of both families converged on relatively cohesive diets in dry seasons but varied in their maintenance of cohesion during wet seasons. Dietary cohesion throughout the timeseries of the subdominant ‘Artists’ family was stronger and more consistently positive compared to the dominant ‘Royals’ family. The greater degree of individuality within the dominant family's timeseries could reflect more divergent nutritional requirements associated with calf-dependency and/or priority access to preferred habitats. Whereas theory predicts that individuals should specialize on different foods under resource scarcity, our data suggest family bonds may promote cohesion and foster the emergence of diverse feeding cultures reflecting links between social behaviour and nutrition.大象个体应根据食物可获得性调整其饮食结构。我们采用DNA宏条形码（DNA metabarcoding）技术，为肯尼亚两个象群的大象构建了个体水平的饮食时间序列数据集，这两个象群在栖息地利用、社会地位以及繁殖状态上均存在差异。本次研究共检测到至少367种取食植物类群，单份粪便样本中最多可检出137条独特的植物序列。研究结果与已被广泛证实的趋势相符：大象在雨季会更多取食草本植物，旱季则转向其他植物类群。在从“草本取食”到“木本啃食”的策略转变中，饮食DNA分析揭示了个体间食物丰富度、组成结构以及取食重叠度的季节性变化。两个象群的大象在旱季均会形成相对统一的饮食结构，但在雨季维持饮食一致性的程度存在差异。相较于占主导地位的“皇室”（Royals）象群，处于从属地位的“艺术家”（Artists）象群在整个饮食时间序列中的饮食一致性更强，且一致性始终为正。占主导地位的“皇室”象群的饮食序列中个体差异更为显著，这可能反映了幼崽依赖相关的营养需求差异，或是该象群优先获取优质栖息地的特性。尽管理论预测在资源匮乏条件下，个体应特化取食不同食物，但我们的数据表明，家族纽带或可促进饮食一致性，并催生多样化的取食文化，这反映了社会行为与营养之间的关联。