Predictors and consequences of diet variation in a declining generalist aerial insectivore

In this study, we examined the predictors and fitness consequences of tree swallow diet variation. We collected fecal samples from breeding tree swallows in Ithaca, NY, USA and performed DNA metabarcoding using the COI gene to identify arthropods in the feces. Using sequencing results, we then identified dietary diversity and aquatic insect content (a proxy for highly unsaturated fatty acid content, an important macronutrient for tree swallows). We examined the consequences of diet variation for tree swallow fitness and fitness-related traits, and we explored predictors of diet variation (phenotypic traits, breeding stage, age, sex, and nest box site).

本研究旨在探讨树木燕子饮食多样性的预测因子及其对健康状态的影响。我们收集了美国纽约州伊萨卡地区繁殖的树木燕子的粪便样本，并利用COI基因进行DNA条形码技术，以识别粪便中的节肢动物。通过测序结果，我们进一步确定了饮食多样性和水生昆虫含量（作为高度不饱和脂肪酸含量的指标，这对树木燕子而言是一种重要的宏量营养素）。此外，我们还研究了饮食多样性对树木燕子健康状态及其相关特征的影响，并探讨了饮食多样性的预测因子（包括表型特征、繁殖阶段、年龄、性别和巢箱位置）。