DNA metabarcoding quantifies the relative biomass of arthropod taxa in songbird diets: Validation with camera‐recorded diets

Ecological research is often hampered by the inability to quantify animal diets. Diet composition can be tracked through DNA metabarcoding of faecal samples, but whether (complex) diets can be quantitatively determined with metabarcoding is still debated and needs validation using free-living animals. This study validates that DNA metabarcoding of faeces can retrieve actual ingested taxa, and most importantly, that read numbers retrieved from sequencing can also be used to quantify the relative biomass of dietary taxa. Validation was done with the hole-nesting insectivorous Pied Flycatcher whose diet was quantified using camera footage. Size-adjusted counts of food items delivered to nestlings were used as a proxy for provided biomass of prey orders and families and subsequently nestling faeces were assessed through DNA metabarcoding. To explore potential effects of digestion, gizzard and lower intestine samples of freshly collected birds were subjected to DNA metabarcoding. For metabar...

生态学研究常因无法量化动物饮食而受阻。饮食组成可通过粪便样本的DNA宏条形码（DNA metabarcoding）技术追踪，但宏条形码能否定量测定（复杂）饮食仍存争议，需通过自由生活动物进行验证。本研究验证：粪便DNA宏条形码可检索实际摄入的类群，更重要的是，测序获得的读数可用于量化饮食类群的相对生物量。验证对象为洞巢食虫性斑姬鹟（Pied Flycatcher），其饮食通过摄像头影像资料量化。调整大小后的投喂给雏鸟的食物项目计数被用作猎物目和科的生物量代理指标，随后通过DNA宏条形码分析雏鸟粪便。为探究消化的潜在影响，对新鲜采集鸟类的肌胃和下肠道样本进行DNA宏条形码分析。对于宏条形码...