Using phenological drivers of demography in conservation

在保护中利用人口学的物候驱动因素

• 批准号: NE/P002986/1
• 负责人: Jennifer Gill
• 金额: $ 74.4万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FP002986%2F1
• 关键词: Using; phenological; drivers; demography; conservation

Understanding density-dependent processes and the conditions that influence their fitness consequences is a key component of population ecology, but the mechanisms determining density-dependent effects in wild populations are rarely understood. Most studies of density-dependent processes have focussed on identifying conditions influencing spatial variation in densities. However, phenological variation among individuals within breeding populations may also influence the strength of local density-dependence, if individual contributions to these processes vary with stage of the reproductive cycle. Synchronous breeding could thus be a major contributor to density-dependent processes within local populations. Identifying links between reproductive synchrony, density-dependence and demography is particularly important in species of conservation concern, for which management to facilitate reproductive synchrony and associated fitness benefits may be possible. In lowland areas of Europe, wading bird populations have undergone severe and widespread declines, and are increasingly restricted to small numbers of nature reserves. Funding mechanisms have been developed within the EU Common Agricultural Policy to attempt to halt and reverse these declines, through agri-environment schemes (AES), but these attempts have failed despite the very large sums of money involved. There is therefore growing recognition of the need to target actions through a much more profound understanding of the interactions between land management and species demography. AES that deliver suitable breeding habitat can successfully attract breeding waders, but high levels of nest and chick predation by generalist predators (primarily red foxes, Vulpes vulpes) consistently prevent population recovery. Ground-nesting waders are inherently vulnerable to predation, and many species have evolved strategies such as semi-colonial breeding and group mobbing of predators to counteract these impacts, but these behavioural adaptations have not previously been considered in the design of AES, and piecemeal deployment of AES that support very small populations may in fact be exacerbating the population declines. Predation rates on wader nests and chicks are generally lower when nesting densities are high, but there is often a great deal of variation in these relationships. The effectiveness of anti-predator behavioural adaptations may be enhanced when breeding is synchronous, as defence behaviour often intensifies through the breeding cycle, but the contribution of reproductive synchrony to these density-dependent processes is unknown. High levels of predation typically result in reproductive asynchrony, as predated nests are replaced throughout the breeding season. The actions of predators may therefore be reducing the effectiveness of anti-predator strategies; a cycle which can potentially be broken through management to facilitate reproductive synchrony. To test the role of reproductive synchrony in driving productivity and population growth, and the potential for management to facilitate reproductive synchrony in species of conservation concern, we propose to carry out a large-scale experimental manipulation of predator distribution and reproductive synchrony in breeding wading bird (northern lapwing, Vanellus vanellus, and common redshank, Tringa totanus) populations on lowland wet grasslands, and to quantify the mechanisms through which synchrony can enhance local productivity. This information will be used to model potential rates of population growth that could be achieved by land management strategies that integrate both environmental and behavioural drivers of population growth. Within-population phenological variation could influence density-dependent processes in a wide range of settings, and identifying these links may therefore substantially improve our understanding of key processes in population ecology and conservation management.

了解密度依赖过程以及影响其适应度后果的条件是种群生态学的关键组成部分，但决定野生种群密度依赖效应的机制却很少被了解。大多数密度相关过程的研究都集中在确定影响密度空间变化的条件。然而，如果个体对这些过程的贡献随繁殖周期阶段的不同而变化，则繁殖种群内个体之间的物候变化也可能影响局部密度依赖性的强度。因此，同步育种可能是当地种群内密度依赖过程的主要贡献者。确定生殖同步性、密度依赖性和人口统计学之间的联系对于受保护的物种尤其重要，对这些物种进行管理以促进生殖同步性和相关的适应性益处是可能的。在欧洲低地地区，涉水鸟类的数量经历了严重而广泛的下降，并且越来越局限于少数自然保护区。欧盟共同农业政策内已经制定了融资机制，试图通过农业环境计划（AES）来阻止和扭转这些下降，但尽管涉及大量资金，但这些尝试都失败了。因此，人们越来越认识到需要通过更深入地了解土地管理和物种人口学之间的相互作用来采取有针对性的行动。提供合适繁殖栖息地的 AES 可以成功吸引繁殖涉禽，但多面性捕食者（主要是红狐、狐狸）对巢穴和雏鸟的高水平捕食始终阻碍种群恢复。地面筑巢涉禽本质上很容易受到捕食，许多物种已经进化出半殖民地繁殖和群体围攻捕食者等策略来抵消这些影响，但这些行为适应以前在 AES 的设计中并未考虑到，而支持非常小的种群的 AES 的零碎部署实际上可能会加剧种群数量的下降。当筑巢密度较高时，涉禽巢和雏鸟的捕食率通常较低，但这些关系往往存在很大差异。当繁殖同步时，反捕食者行为适应的有效性可能会增强，因为防御行为通常会在繁殖周期中加强，但繁殖同步对这些密度依赖过程的贡献尚不清楚。高水平的捕食通常会导致繁殖异步，因为被捕食的巢穴在整个繁殖季节都会被更换。因此，捕食者的行为可能会降低反捕食者策略的有效性；通过管理有可能打破这一循环，以促进生殖同步。为了测试生殖同步性在推动生产力和种群增长中的作用，以及管理促进受保护物种生殖同步性的潜力，我们建议对低地湿地涉水鸟类（北方田凫、Vanellus vanellus 和普通赤脚鹬、Tringa totanus）繁殖种群的捕食者分布和生殖同步性进行大规模实验操作。 草原，并量化同步可以提高当地生产力的机制。这些信息将用于模拟潜在的人口增长率，该增长率可以通过整合人口增长的环境和行为驱动因素的土地管理战略来实现。种群内物候变化可能会影响多种环境中的密度依赖过程，因此识别这些联系可能会大大提高我们对种群生态和保护管理关键过程的理解。

项目成果

Impacts of grassland management on wader nest predation rates in adjacent nature reserves

草原管理对邻近自然保护区鸻鹬被捕食率的影响

• DOI: 10.1111/acv.12283
• 发表时间: 2017
• 期刊: Animal Conservation
• 影响因子: 3.4
• 作者: Leigh S

Nest survival of threatened Eurasian Curlew ( Numenius arquata ) breeding at low densities across a human-modified landscape

受威胁的欧亚杓鹬（Numenius arquata）在人工改造景观中低密度繁殖的巢穴生存

• DOI: 10.1111/ibi.13180
• 发表时间: 2023
• 期刊: Ibis
• 影响因子: 2.1
• 作者: Ewing H

Foxes, voles, and waders: drivers of predator activity in wet grassland landscapes

狐狸、田鼠和涉禽：潮湿草原中捕食者活动的驱动因素

• DOI: 10.5751/ace-01414-140204
• 发表时间: 2019
• 期刊: Avian Conservation and Ecology
• 影响因子: 1.4
• 作者: Laidlaw R

Defining and delivering resilient ecological networks: Nature conservation in England

• DOI: 10.1111/1365-2664.13196
• 发表时间: 2018-11-01
• 期刊: JOURNAL OF APPLIED ECOLOGY
• 影响因子: 5.7
• 作者: Isaac, Nick J. B.;Brotherton, Peter N. M.;Mace, Georgina M.
• 通讯作者: Mace, Georgina M.

Landscape effects on nest site selection and nest success of Northern Lapwing Vanellus vanellus in lowland wet grasslands

• DOI: 10.1080/00063657.2016.1262816
• 发表时间: 2017-02-24
• 期刊: BIRD STUDY
• 影响因子: 0.7
• 作者: Bertholdt, Nikolas P.;Gill, Jennifer A.;Smart, Jennifer
• 通讯作者: Smart, Jennifer