The role of dispersal in range change by birds

扩散可以说是人口学中最不为人所知的组成部分，但理解它是回答重要生态学问题的关键：物种对气候变化的反应速度有多快？亚种群之间的联系有多紧密？入侵物种到达一个新地点需要多长时间？该项目利用了最全面的动物运动数据集之一，对英国碎片化景观中的扩散过程有了新的认识。这个项目将使用芦苇莺，一种常见的候鸟，在英格兰南部和中部的芦苇床上发现。英国鸟类学信托基金会（CASE在这个项目上的合作伙伴）有大量繁殖季节之间运动的数据集（大约3000个个体运动），这些数据集是由公民科学产生的。利用广泛的芦苇莺数据集，结合目前由CASE合作伙伴进行的精细运动的实地调查，学生将开发和测试统计方法，以表征扩散，然后可以应用于更有限的恢复数据集的更广泛的物种。该项目由三个部分组成：(1)明确的芦莺分布范围变化的时空人口统计学模型。该部分将对现有的BTO数据集应用最先进的统计和理论模型，以探索最近的范围变化是由分散的变化还是由繁殖生存成功的变化驱动的。(2)现场工作将作为BTO正在进行的研究的一部分进行。已经建立了一个单独标记的芦苇莺种群，并在一个大芦苇床上监测了在繁殖季节之间标记鸟的精细运动。这项研究将使实地工作扩展到邻近的繁殖区域，实地工作的重点是绘制主要野外地点20公里内所有芦苇莺的领地，并识别核心区以外所有单独标记的鸟类。这些数据将与更大规模的现有数据相结合，以确保学生对空间尺度范围内的分散有充分的了解：了解有多少个体无处移动与有多少个体长距离移动同样重要。(3)项目的最后阶段将涉及将范围扩大到多个物种。利用从第一部分和第二部分获得的见解，将选择适当的分散模型并应用于更广泛的BTO振铃数据集。该项目的这一部分不仅将使更多的物种被纳入，而且将使学生能够评估许多物种的分散行为的变化是否可以被视为全球变化的结果。在这个项目中收集的信息将对致力于为英格兰制定空间保护计划的政府和非政府组织有用，同时也证明了关于新的自然区域（如生物多样性抵消产生的自然区域）可能最有效地定位的有用信息，以确保物种可以移动和殖民。

Dispersal is arguably the poorest understood component of demography, yet understanding it is key to answering important ecological questions: how fast will species respond to changing climates? How well are sub-populations connected? How long will invasive species take to reach a new site? This project makes use of one of the most comprehensive datasets on animal movement available to develop a new understanding of dispersal processes in the UK's fragmented landscape.This project will use Reed warblers, a common migrant bird species found in reed beds across southern and central England. The British Trust for Ornithology (CASE partner on this project) has large dataset of movement between breeding seasons (c. 3000 individual movements) generated from citizen science. Using the extensive reed warbler dataset, combined with fieldwork on fine-scale movements currently undertaken by the CASE partner, the student will develop and test statistical methods to characterise dispersal that can then be applied to a wide range of species with more limited recovery datasets. The project has three components:(1) a spatio-temporally explicit demographic model of reed warbler range change. This component will apply state of the art statistical and theoretical models to the existing BTO datasets to explore whether recent range change is driven by changes in dispersal or by changes in breeding success of survival.(2) Fieldwork will be undertaken as part of ongoing research by BTO. A population of individually marked reed warblers has been established and the fine-scale movements of marked birds between breeding season is being monitored within a large reed bed. This studentship will enable expansion of the fieldwork to neighbouring breeding areas, with fieldwork focussing on mapping all reed warbler territories within 20km of the primary field site and identifying all individually marked birds outside the core area. These data will be combined with the larger scale existing data to ensure the student has a full understanding of dispersal at a range of spatial scales: it is just as important to know how many individuals move nowhere as how many move long distances.(3) The final stage of the project will involve broadening the scope to multiple species. Using the insights gained from parts one and two, appropriate dispersal models will be selected and applied to the wider BTO ringing dataset. This component of the project will not only enable more species to be incorporated, but will allow the student to assess whether dispersal behaviour in changing in many species may be seen as a consequence of global change. The information gathered during this project will be useful to governmental and non-governmental organisations working to develop spatial conservation plans for England, as well as proving useful information about where new nature areas (such as those created by biodiversity offsetting) may be most effectively sited to ensure species can move and colonise them,