What's for dinner? Oceanographic drivers of Manx shearwater chick provisioning and growth

众所周知，海洋特征（如锋面、环流和涡流）聚集了远洋饲料鱼类，从而影响了海洋捕食者的空间利用1,2。这些特征是动态的，其特征（如力量、持久性、位置）的变化对猎物的可得性、觅食努力和繁殖成功都有影响。NERC SHEAR项目目前正在量化物理海洋学特征和猎物可用性之间的联系和相互作用如何影响马恩岛shearwater觅食能量学，这是一种已知的与海洋学特征密切相关的中上层潜水海鸟。然而，人们对曼氏鹱的饮食构成仍有很大的了解，部分原因是以前研究这些鸟类饮食的方法是侵入性的。DNA元条形码和侵入性较小的取样技术正在改变对这些物种的饮食研究。此外，人们对海洋特征的变化如何在关键觅食区域驱动特定猎物物种（如鱿鱼和小棍棒鱼）的可用性知之甚少。这一点很重要，因为猎物种类的热值差别很大，而且主要由“垃圾食品”组成的饮食对海鸟后代的生长和生存有重大影响。这个多学科项目将确定海洋特征特征和饲料鱼类物种之间的精细尺度联系，并利用生物学、eDNA分析、形态测量和物理海洋学的结合，量化海鸥雏鸟生长的关键驱动因素。具体来说，这个项目有三个核心问题：1。海洋物理特征是否决定了海鸥觅食的深度和努力？在觅食过程中，食物的大小和饮食是否取决于海洋物理特征的特征？问题1和问题2能解释小鸡的生长吗？

Oceanographic features (e.g. fronts, gyres and eddies) are known to aggregate pelagic forage fish andthereby shape the space use of marine predators1,2. These features are dynamic and changes in theircharacteristics (e.g. strength, persistence, position) has consequences for prey availability, foraging effortand breeding success3. The NERC SHEAR project is currently quantifying how the association andinteraction between physical oceanographic features and prey availability impacts Manx shearwaterforaging energetics, a pelagic diving seabird known to forage in close association with oceanographicfeatures. However, there is a significant knowledge gap surrounding the diet composition of Manxshearwaters4 which is partly because previous methods for studying the diet of these birds have beeninvasive. DNA metabarcoding and less invasive sampling techniques are now transforming diet studies ofsuch species5. Furthermore, less is known about how variation in oceanographic features drive theavailability of specific prey species (i.e., squid and small Clupeid fish) within key foraging areas. This isimportant as prey species differ significantly in calorific value, and diets consisting predominantly of 'junkfood' have had significant consequences for the growth and survival of seabird offspring6. Thismultidisciplinary project will identify the fine-scale links between characteristics of oceanographic featuresand species of forage fish as well as quantify the key drivers of shearwater chick growth using acombination of biologging, eDNA analysis, morphometric measurements, and physical oceanography.Specifically, this project has three core questions:1. Does the characteristics of physical oceanographic features determine shearwater foraging depthand effort?2. Is meal size and diet determined by the characteristics of physical oceanographic features targetedduring foraging trips?3. Is chick growth explained by Qs 1 & 2?