Diet of a threatened rattlesnake (eastern massasauga) revealed by DNA metabarcoding

Characterizing the diet of imperiled species using minimally invasive methods is crucial to understanding their ecology and conservation requirements. Here, we apply a DNA metabarcoding approach to study the diet of the eastern massasauga rattlesnake (Sistrurus catenatus), a Federally Threatened snake found throughout the Great Lakes region. Eighty-three fecal samples collected across 10 different massasauga populations located in Michigan, USA, were sequenced, with 70 samples containing prey DNA. We used universal metazoan primers and developed a host-specific oligonucleotide blocker to characterize their diet. We identified at least 12 different prey species, with eastern massasaugas exhibiting opportunistic feeding and a strong preference towards small mammals. Meadow voles (Microtus pennsylvanicus) were the most common prey item (70% of diet) followed by the northern short-tailed shrew (Blarina brevicauda) and masked shrew (Sorex cinereus; 15.7% of diet each), along with occasional ..., ,采用微创方法对濒危物种的食性进行表征，对于理解其生态学特征与保护需求至关重要。本研究采用DNA元条形码（DNA metabarcoding）技术，对分布于五大湖地区的联邦受威胁物种——东部马萨苏加响尾蛇（Sistrurus catenatus）的食性展开研究。研究人员对采自美国密歇根州10个不同马萨苏加响尾蛇种群的83份粪便样本进行测序，其中70份样本检出猎物DNA。本研究使用通用后生动物引物，并开发了宿主特异性寡核苷酸阻断剂，以精准表征该物种的食性。研究共鉴定出至少12种不同的猎物物种，结果显示东部马萨苏加响尾蛇为机会主义捕食者，且对小型哺乳类具有显著偏好。草原田鼠（Microtus pennsylvanicus）为最主要的猎物类型，占食谱的70%；其次为北方短尾鼩（Blarina brevicauda）与灰鼩鼱（Sorex cinereus），二者各占食谱的15.7%，此外还有偶见的……