What mechanisms drive avian demographic and population responses to climatic change?

什么机制驱动鸟类人口和种群对气候变化的反应？

• 批准号: NE/H018735/1
• 负责人: Ben Hatchwell
• 金额: $ 8.94万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Training Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH018735%2F1
• 关键词: What; mechanisms; drive; avian; demographic

Our current understanding of the mechanisms underlying the impacts of climatic change on biodiversity is rudimentary, hindering the development of accurate predictions of these impacts, and appropriate adaptation and mitigation. The aim of this project is to determine the mechanism(s) through which the effects of climatic change on a temperate bird species are mediated. Demography determines population trends, and thus ultimately the range expansions and contractions that climate change is widely predicted to generate. Therefore, there is an urgent need to understand the mechanistic links between climatic change, demography and population trends. The research that has been conducted to date in this area has focused predominantly on the trophic mismatch hypothesis, which has most frequently been applied to birds. It suggests that species whose lay dates have not advanced at the same rate as spring temperatures are likely to breed after the peak in food availability, resulting in reduced reproductive success, and hence population declines. In contrast, species with marked advances in lay date are predicted to have high reproductive success and stable or increasing populations. The trophic mismatch hypothesis is frequently considered to provide a robust explanation for avian population trends in response to climatic change. Surprisingly, however, it receives support from studies of just two bird species. Moreover, alternative demographic mechanisms may explain associations between climatic change and population trends. Temperate bird species have tightly constrained breeding seasons, which may be lengthened by earlier reproduction, thus increasing the number of breeding attempts and the probability of breeding successfully, e.g. by reducing the impact of nest predation events. In resident bird species, winter mortality frequently regulates population size and is likely to be reduced by climatic amelioration thus generating population growth. This CASE studentship will provide the first rigorous test of these alternative demographic mechanisms linking climatic change with population trends. It uses the long-tailed tit Aegithalos caudatus as a model system. This species is ideal for this study as it exhibits the most marked phenological advance in lay date of any resident small passerine in the UK, its population is rapidly increasing, and it experiences high rates of nest predation and, in cold weather, winter mortality. The studentship combines analysis of national and local long-term datasets on breeding success, survival and recruitment, with intensive localised fieldwork to determine the relative effects of climate-induced changes in breeding phenology, predation resistance and winter survival on population size. Intensive study of a long-tailed tit population near Sheffield will provide 20 years of detailed data on population ecology and behaviour (17 years of data will be available when the studentship starts, with an additional 3 years of data collated during the studentship). The national schemes run by the British Trust for Ornithology (BTO), including its ringing programmes and nest record scheme, will provide data on a UK-wide scale. The BTO CASE partner is globally recognised as a world leader in assessing avian responses to environmental change, with regard to both population trends and the underlying causal demographic mechanisms. The training provided by the BTO in statistical modelling of demographic parameters and population trends thus adds real value to the studentship. Moreover, as an independent research organisation with close links to both the conservation and political communities the BTO CASE partner is ideally placed to facilitate knowledge transfer, thus maximising the impact of the results of this CASE studentship.

我们目前对气候变化对生物多样性影响的机制的理解是基本的，阻碍了对这些影响的准确预测的发展，以及适当的适应和缓解。该项目的目的是确定气候变化对温带鸟类物种的影响的机制。人口统计学决定了人口趋势，因此最终会广泛预测气候变化的范围扩展和收缩。因此，迫切需要了解气候变化，人口统计学和人口趋势之间的机械联系。迄今为止在该领域进行的研究主要集中在营养不匹配的假设上，该假设最常用于鸟类。它表明，在食品可利用性高峰之后，铺设日期的物种没有以与春季温度相同的速度繁殖，从而导致生殖成功降低，因此人口下降。相比之下，预计外行日期明显进展的物种将具有很高的生殖成功，人口稳定或增加。经常认为，营养不匹配的假设为响应气候变化的鸟类种群趋势提供了强有力的解释。但是，令人惊讶的是，它得到了仅研究两种鸟类的支持。此外，替代性人口机制可以解释气候变化与人口趋势之间的关联。温带鸟类物种的繁殖季节严格严格，可以通过较早的繁殖来延长，从而增加了育种尝试的数量和成功繁殖的可能性，例如通过减少巢捕食事件的影响。在常驻鸟类物种中，冬季死亡率经常调节人口规模，并且可能会通过气候改善而减少，从而导致人口增长。该案例学生将对这些替代人口统计学机制进行首次严格测试，将气候变化与人口趋势联系起来。它使用长尾的山雀aegithalos caudatus作为模型系统。该物种是这项研究的理想选择，因为它在英国任何居民小雀形的日期表现出最明显的物候进展，其人口正在迅速增加，并且经历了高巢捕食率，并且在寒冷的天气中，冬季死亡率。该学生培训结合了对国家和地方长期数据集关于繁殖成功，生存和招聘的分析，以及密集的局部实地调查，以确定气候引起的繁殖物候，捕食性和冬季生存对人口规模的相对影响。对谢菲尔德附近的长尾山雀人群的深入研究将提供20年的人群生态和行为数据（学生奖学金开始时将获得17年的数据，并在学生奖励期间又有3年的数据进行了3年的数据）。由英国鸟类学信托基金（BTO）制定的国家计划（包括其响铃计划和巢记录计划）将以英国范围的规模提供数据。关于人口趋势和基本因果人口机制，BTO案件伙伴在全球范围内被公认为评估鸟类对环境变化的反应。 BTO在人口参数和人口趋势的统计模型中提供的培训为学生提供了实际价值。此外，作为一个与保护和政治社区密切相关的独立研究组织，BTO案件伙伴是理想的选择，以促进知识转移，从而最大程度地提高了该案件学生奖学金结果的影响。