Understanding how urbanisation impacts diet and fitness of a well-known garden bird, the Blue Tit

城市化改变了世界大部分地区的栖息地，导致当地环境条件改变，污染加剧，社区组成发生变化，食物供应也发生了变化。一些物种能够利用这些栖息地(“赢家”)，而一些物种能够在一定程度上适应或适应(“适应者”)，而其他物种则被迫离开或遭受当地种群灭绝(“逃避者”)。总体而言，城市地区出现了物种丰富度较低的总体格局。为了在快速城市化的世界中维持生物多样性，了解在这些无处不在的环境中，哪些因素影响物种的成功(或失败)变得越来越重要。广为人知的花园鸟--蓝山雀(Cyanistes Caeruleus)--最初似乎是成功利用城市环境的赢家。事实上，成年鸟类可能会受益于更温暖的冬季温度和人类提供的补充食物资源。然而，在繁殖季节，城市实际上可能成为蓝山雀的“生态陷阱”，因为它们缺乏快速成长的雏鸟的专业饮食中所需的脂肪和富含蛋白质的毛虫。几项研究表明，在城市繁殖的蓝山雀实际上比在森林中繁殖的鸟类繁殖成功率更低，但这种模式的原因尚不清楚。在这个项目中，学生将与来自格拉斯哥大学的合作者密切合作，在从格拉斯哥市中心到一个未受干扰的橡树林研究站的城市化梯度上的长期生态研究地点。这项研究的目标是研究：1)雏鸟蓝山雀的饮食如何随着城市化梯度的变化而变化，2)父母的饮食和状况如何随着城市化梯度的变化而变化。由于以前很难分析高分辨率的食物(例如，视频中喂给雏鸟的食物只能被粗略地归类为毛毛虫和非毛毛虫)，关于食物可获得性对城市物种繁殖成功的影响的假说在很大程度上还没有被探索，饮食可能提供了理解城市物种持续和灭绝的缺失环节。该项目将为学生提供现场和实验室的全面体验。她/他将参加在苏格兰的实地工作，这将包括为鸟类设置雾网，收集形态测量数据，并进行遥测以调查觅食努力。在实验室中，学生将对父母和雏鸟进行饮食DNA代谢编码。在这种方法中，从鸟类的粪便样本中提取饮食项目的DNA，然后在下一代高通量平台上进行测序，以同时获得多达200只鸟类的数百种饮食项目的序列。这将提供鸟类在繁殖季节和全年消耗的食物的高分辨率细节。强大的生物信息学方法将确定饮食项目的分类和潜在的关于丰度的信息，然后将进行统计分析，以确定地点之间和时间上的显著差异。

Urbanisation has transformed habitats across much of the world, leading to altered local environmental conditions, increased pollution, changes in community composition, and altered food availability. Some species are able to exploit these habitats ("winners"), while some are able to cope or adjust to a degree ("adapters"), and others are forced to either disperse away or suffer local population extinction ("avoiders"). Overall, a general pattern of lower species richness in urban areas has emerged. It is becoming increasingly important to understand what factors influence species' success (or failure) in these ubiquitous environments in order to maintain biodiversity in a rapidly urbanising world. The widely known garden bird, the blue tit (Cyanistes caeruleus), may initially appear to be a winner at successfully exploiting urban environments. Indeed, adult birds may benefit from warmer winter temperatures and supplemental food resources provided by humans. However, during the breeding season, cities may actually become "ecological traps" for blue tits because they have limited availability of fat and protein-rich caterpillars required in the specialist diets of rapidly growing chicks. Several studies have demonstrated that blue tits breeding in cities actually have lower reproductive success than birds breeding in forested sites, yet the causes of this pattern remain unclear. In this project, the student will work closely with collaborators from Glasgow University at long-term ecological research sites along an urbanisation gradient from the heart of urban Glasgow to an undisturbed oak forested research station. The goals of this study are to examine: 1) How the diets of nestling blue tits change along the urbanisation gradient, 2) How the diets and condition of parents varies along the gradient and throughout the year. Because of the previous difficulty in analysing diets in high resolution (e.g., diet items fed to chicks on video can only be crudely classified as caterpillar vs. non-caterpillar), hypotheses about the impacts of food availability on urban species' reproductive success have largely been unexplored, and diet may provide a missing link in understanding species' persistence and extirpation in cities. This project will provide the student comprehensive experience in both the field and the lab. She/he will participate in fieldwork in Scotland, which will involve mist netting birds, collecting morphometric data, and conducting telemetry to investigate foraging effort. In the lab, the student will conduct diet DNA metabarcoding of both the parents and the chicks. In this approach, DNA from diet items is extracted from faecal samples of the birds, and then sequenced on a next-generation, high throughput platform, to obtain the sequences of hundreds of diet items from up to 200 birds simultaneously. This will provide high-resolution detail of the diets consumed by the birds both during the breeding season and throughout the year. Powerful bioinformatics approaches will identify the taxonomy of the diet items and potentially information about abundance, and then statistical analyses will be carried out to identify significant differences between sites and through time.