Dataset S9 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.个体动物需根据食物可获得性灵活调整饮食策略。本研究采用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，这两个象群在栖息地利用模式、社会地位以及繁殖状态上均存在差异。研究共检测到至少367种食用植物类群，单份粪便样本中最多可检出137条独特的植物序列。研究结果契合学界公认的取食规律：大象在雨季倾向于更多取食草本植物，旱季则转向其他类别的植被。在这种从“放牧型取食”到“浏览型取食”的策略转变中，饮食DNA分析揭示了个体间食物丰富度、群落组成以及食物重叠度的季节动态变化。两个象群的大象在旱季均会形成相对统一的饮食结构，但在雨季维持这种饮食统一性的程度存在显著差异。相较于优势群“Royals”，从属群“Artists”的饮食时间序列中，其饮食统一性更强，且个体间的饮食重叠度始终维持在较高水平。优势群“Royals”的饮食时间序列中个体间的差异性更高，这或许反映了该群体的营养需求更为多样化——这与幼崽抚育需求相关，或是该群体能够优先获取优质栖息地。尽管理论预测在资源匮乏条件下，个体应特化取食不同的食物，但本研究数据表明，家族纽带或许能促进饮食统一性，并催生多样化的取食文化，这一结果反映了社会行为与营养之间的内在关联。