Data from: Molecular detection of invertebrate prey in vertebrate diets: trophic ecology of Caribbean island lizards

Understanding community assembly and population dynamics frequently requires detailed knowledge of food web structure. For many consumers, obtaining precise information about diet composition has traditionally required sacrificing animals or other highly invasive procedures, generating tension between maintaining intact study populations and knowing what they eat. We developed 16S mitochondrial DNA sequencing methods to identify arthropods in the diets of generalist vertebrate predators without requiring a blocking primer. We demonstrate the utility of these methods for a common Caribbean lizard that has been intensively studied in the context of small island food webs: Anolis sagrei (a semi-arboreal ‘trunk-ground’ anole ecomorph). Novel PCR primers were identified in silico and tested in vitro. Illumina sequencing successfully characterized the arthropod component of 168 faecal DNA samples collected during three field trips spanning 12 months, revealing 217 molecular operational taxonomic units (mOTUs) from at least nine arthropod orders (including Araneae, Blattodea, Coleoptera, Hemiptera, Hymenoptera, Isoptera, Lepidoptera and Orthoptera). Three mOTUs (one beetle, one cockroach and one ant) were particularly frequent, occurring in ≥50% of samples, but the majority of mOTUs were infrequent (180, or 83%, occurred in ≤5% of samples). Species accumulation curves showed that dietary richness and composition were similar between size-dimorphic sexes; however, female lizards had greater per-sample dietary richness than males. Overall diet composition (but not richness) was significantly different across seasons, and we found more pronounced interindividual variation in December than in May. These methods will be generally useful in characterizing the diets of diverse insectivorous vertebrates.解析群落组装与种群动态，往往需要对食物网结构具备详尽认知。对于多数消费者类群而言，传统上要获取其饮食组成的精准信息，需通过处死动物或其他高侵入性手段，这在维持完整研究种群与探明其摄食对象之间产生了矛盾。我们开发了16S线粒体DNA（16S mitochondrial DNA）测序方法，可在无需封闭引物的前提下，鉴定广食性脊椎动物捕食者饮食中的节肢动物组分。我们针对一类因小型岛屿食物网研究而被深入探究的加勒比常见蜥蜴——安乐蜥（*Anolis sagrei*，一种半树栖的‘树干-地面’型安乐蜥生态形态），验证了该方法的实用性。我们通过计算机模拟筛选得到新型聚合酶链式反应（PCR）引物，并开展体外实验验证。Illumina测序成功解析了12个月内三次野外考察采集获得的168份粪便DNA样本中的节肢动物组分，共检测到至少9个节肢动物纲（包括蜘蛛目、蜚蠊目、鞘翅目、半翅目、膜翅目、等翅目、鳞翅目及直翅目）的217个分子操作分类单元（molecular operational taxonomic units，mOTUs）。其中3个分子操作分类单元（mOTUs）（分别对应1种甲虫、1种蜚蠊与1种蚂蚁）出现频率极高，在≥50%的样本中均可检出；但绝大多数mOTUs较为稀有——180个（占比83%）仅在≤5%的样本中出现。物种累积曲线分析显示，体型二态的雌雄两性的饮食丰富度与组成相似，但雌性安乐蜥的单样本饮食丰富度高于雄性。整体饮食组成（而非丰富度）在不同季节间存在显著差异，且12月的个体间饮食差异较5月更为显著。该方法可广泛用于解析多样食虫脊椎动物的饮食组成。