Drivers of individual foraging/behaviour specialisation in a model seabird: The Falkland Islands shag

本博士将通过研究福克兰岛沙虫（Leucocarbo atriceps albiventer）来研究种内竞争和环境变化如何影响个体觅食行为的专业化。这一物种是南大洋一群鲜为人知的物种/亚种的一部分，其中许多物种，包括福克兰岛的长尾鲨，都没有被详细研究过。然而，作为一种分布广泛的常驻海鸟，它提供了一个模型系统，不仅可以跟踪来自不同大小和不同海洋环境的群体的个体；但是要全年研究这些对比。这些特征使这个物种成为一个优秀的模型，可以在竞争梯度（群体大小）和环境条件（近海和近海群体以及生产力和白天长度的季节性变化）中进行“自然实验”，通过这些实验来研究觅食/行为专业化中个体差异的驱动因素。个体变异越来越被认为是我们理解生态和进化过程的核心，并且对物种保护具有重要意义。特别是，行为差异（“个性”）的相关性和程度，以及个体表现出的可塑性或专业化程度，对包括生存和繁殖成功在内的一系列关键特征具有重要影响。这些影响转化为种群水平的影响，因为它们影响个体对人为威胁的易感性。虽然个体之间的行为差异通常是很清楚的，但从经验上来说，人们对驱使个体在不同背景下进行概括或专业化的原因知之甚少。经典的生态位理论认为，增加的种内竞争（即自上而下的效应）推动了个体专业化水平的提高。然而，环境机会和资源可用性（即自下而上效应）也因时间和空间而异，例如由于人为影响和季节性，并代表一个独立的梯度，对生态位分化产生重要影响。这个多学科项目将从福克兰群岛周围的多个群落收集新信息：1)通过生物记录设备（例如GPS，加速度计和潜水深度标签）收集海上行为；2)使用稳定同位素，DNA元条形码和反流分析收集食物偏好；3)将通过最先进的统计模型将其结合起来。最终，这个项目将使我们通过生态位理论的实证检验做出重要的科学和应用贡献。-为拟议的福克兰群岛海洋管理区提供信息，并通过建立一种重要但鲜为人知的近岸捕食者的基线数据，改善对当前和未来采掘业的环境影响评估。

This PhD will investigate how intra-specific competition and environmental variation influence individual specialisation in foraging behaviours by studying the Falkland Island shag (Leucocarbo atriceps albiventer). This species is part of a Southern Ocean complex of poorly known species/subspecies, many of which, including the Falkland Island shag, have not been studied in detail. However, as a widely-distributed resident seabird, it offers a model system to not only follow individuals from colonies of varying size and with access to different oceanographic environments; but to examine these contrasts year-round. Such characteristics make this species an excellent model to run a 'natural experiment' across gradients of competition (colony size) and environmental conditions (inshore and offshore colonies and seasonal variation in productivity and daylength) through which to examine drivers of individual variation in foraging/behavioural specialization. Individual variation is increasingly recognised as being central to our understanding of ecological and evolutionary processes, and has important implications for species conservation. In particular, the relevance and extent of consistent behavioural differences ('personality'), and the degree of plasticity or specialisation shown by individuals, has important consequences for a range of key traits including survival and reproductive success. These translate into population level impacts because they influence the susceptibility of individuals to anthropogenic threats. While behavioural variation among individuals is often clear, what is less well understood empirically is what drives individuals to generalise or specialise across contexts. Classical niche theory suggests that increased intra-specific competition (i.e. top-down effects) drives increasing levels of individual specialisation. However, environmental opportunity and resource availability (i.e. bottom-up effects), also vary temporally and spatially, for example as a result of anthropogenic impacts and seasonality, and represent an independent gradient with important consequences for niche divergence. This multidisciplinary project will collect novel information from multiple colonies around the Falkland Islands on 1)at-sea behaviour via biologging devices (e.g. GPS, accelerometry and dive-depth tags) 2)foraging preferences using stable isotope, DNA metabarcoding and regurgitate analysis, and 3)will combine it through state of the art statistical modelling. Ultimately, this project will allow us to make important scientific and applied contributions through: - Empirical testing of ecological niche theory. - Informing proposed Falkland Islands Marine Managed Areas and improving environmental impact assessments for current, and future, extractive industries through building baseline data on an important but poorly known nearshore predator.