Dataset S12 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.动物个体应依据食物可获取情况调整饮食策略。本研究采用DNA宏条形码（DNA metabarcoding）技术，为肯尼亚两个大象家族群的个体构建了饮食时间序列，这两个家族群在栖息地利用、社会地位与繁殖状态上均存在差异。本次检测共识别出至少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。研究结果契合已被证实的规律：大象在雨季倾向于取食更多草本植物，旱季则转向其他植物类群。在从「放牧型取食」到「啃食型取食」的策略转换背后，饮食DNA分析揭示了个体间食物丰富度、组成及饮食重叠度的季节变化。两个家族群的大象在旱季均形成了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「王室（Royals）」家族群，处于次要地位的「艺术家（Artists）」家族群在整个时间序列中的饮食一致性更强，且整体呈现出更持续的正相关特征。占主导地位的家族群时间序列中呈现出更高的个体差异性，这或许反映了与幼崽抚育依赖相关的营养需求差异，或是其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，但本研究数据表明，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需求之间的内在联系。