How does supplemental feeding effect demography and reproductive fitness in endangered bird species on Mauritius?"

科学背景：越来越多的受威胁物种需要某种形式的人类干预才能生存。生态管理的一种常见形式是提供补充食物，通常是为了在自然资源被认为限制人口增长的地方提高生产力。然而，这样做的确切影响很少被评估，并且可能包括与疾病传播和行为适应相关的意外负面后果2，因此鼓励自然觅食是可取的;这样做在恢复生态群落时也有明显的好处。研究方法：学生将研究毛里求斯两种同域性濒危鸟类的个体水平的饮食组成;粉红鸽（Nesoenas mayeri）和毛里求斯长尾鹦鹉（Psittacula echo）。这两种动物都得到了补充食物，监督小组在该系统中开发了方法，通过（a）分析羽毛的稳定同位素特征3和（B）使用下一代测序技术来确定重要的食用植物物种4来量化个体消费量。学生将使用这些信息以及这些单独标记的种群5的生殖健康的长期数据，以便（i）评估补充喂养在调节种群中的作用，以及（ii）确定重要的本地植物食物来源和相关的栖息地片段在这个裸露的森林生态系统。这种新的方法将定制人工喂养策略，以促进种群恢复，并指导地方性森林及其生态功能的恢复。

Scientific background: An increasing number of threatened species require some form of human intervention in order to persist. A common form of ecological management is to provide supplemental food, often in an effort to increase productivity where natural resources are believed to be limiting population growth1. The precise impacts of doing so however, are rarely evaluated and can include unintended negative consequences associated with disease transmission and behavioural adaptations2, so encouraging natural foraging is desirable; doing so also has clear benefits when restoring ecological communities. Characterising individual dietary composition can be challenging, but is crucial in order to better target individuals or populations most likely to benefit from provisioning.Research methodology: The student will characterise individual-level dietary composition of two sympatrically occurring endangered bird species in Mauritius; the pink pigeon (Nesoenas mayeri) and Mauritius parakeet (Psittacula echo). Both are offered supplemental food and methods have been developed in this system by the supervisory team to quantify individual consumption by (a) analysing stable isotope signatures of feathers3, and (b) using Next-Generation-Sequencing techniques to identify important food plant species4. The student will use this information alongside long-term data on reproductive fitness for these individually-marked populations5, in order to (i) evaluate the role of supplemental feeding in regulating populations, and (ii) identify important native plant food-sources and associated habitat fragments in this denuded forest ecosystem. This novel approach will tailor supplementary-feeding strategies to enhance population recovery and guide restoration of endemic forests and their ecological function.