Individual specialization in resource use by a far-ranging marine predator: incidence and implications

远距离海洋捕食者资源利用的个体专业化：发生率和影响

• 批准号: NE/H007423/1
• 负责人: Stuart Bearhop
• 金额: $ 36.74万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research 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%2FH007423%2F1
• 关键词: Individual; specialization; resource; use; far

Treating all individuals within a population as ecologically equivalent is an oversimplification and ignoring variation among individuals, particularly with respect to resource use, is likely to impede our ability to grasp a suite of ecological and evolutionary processes. Individual specialization in diet and foraging behaviour has important implications for ecology, evolution (including speciation) and conservation but remains largely unevaluated and poorly understood for most free-living consumers, particularly those that forage over long distances. Some of the longest foraging ranges are found among marine predators where, for instance, pelagic seabirds routinely travel tens to hundreds of kilometres from the breeding site on a single trip. Marine predators are currently facing an unprecedented rate of environmental change as a result of rapid climate-driven changes at lower trophic levels combined with direct effects of industrial and commercial fisheries on prey species. In addition, commercial fisheries currently provide huge quantities of food for some species in the form of bait, undersized catch and offal. Responses of different species to these changes in food availability have been well documented at population level but such data typically mask substantial unexplained variation in responses of individuals. Here we propose to examine the incidence and implications of individual variation in resource use by northern gannets as a model far-ranging marine predator that feeds extensively on both fishery discards and pelagic fish. Resource availability to individuals is often strongly affected by competition with other population members, yet surprisingly little attempt has been made to date to place the responses of marine predators to environmental change within the broader context of density-dependent patterns of resource use. Understanding the nature of individual specializations also has important conservation implications for predicting the response and likely consequences of fisheries and climate related change for apex marine predators. Accordingly in this project, we shall: (i) relate dietary specialization of gannets to individual variation in foraging locations, prey search patterns and capture techniques; (ii) examine the extent of density-dependence of both population-level dietary breadth and individual specialization in diet and foraging behaviour, and; (iii) determine the consequences of individual specialization for different components of reproductive fitness. In addition to answering fundamental questions concerning the generation and maintenance of individual specializations within populations of generalist predators, we shall provide vital information on the foraging ranges and core foraging areas of birds at different colonies. These data will be of great value to conservationists and policy makers concerned with the identification of Important Bird Areas and the establishment of Marine Protected Areas in European waters. We shall also provide information in unprecedented detail on the incidence and consequences of reliance on fisheries discards at different colonies as well as the importance of small shoaling fish (e.g. sandeels). This information is essential to make accurate predictions of population-level impacts of proposed changes to fishery discarding practices in Europe and climate related impacts on the availability of naturally occurring forage fish.

将种群中的所有个体都视为生态等效是一种过度简化，忽视个体之间的差异，特别是在资源利用方面，可能会阻碍我们掌握一系列生态和进化过程的能力。个体在饮食和觅食行为方面的专业化对生态学、进化（包括物种形成）和保护具有重要意义，但对于大多数自由生活的消费者，特别是那些长距离觅食的消费者来说，这一点在很大程度上仍未得到评估和了解。一些觅食范围最长的是海洋食肉动物，例如，远洋海鸟一次旅行通常从繁殖地出发数十至数百公里。由于气候驱动的低营养水平的快速变化，加上工业和商业渔业对被捕食物种的直接影响，海洋食肉动物目前正面临着前所未有的环境变化速度。此外，商业渔业目前以鱼饵、小型渔获物和内脏的形式为一些鱼种提供大量食物。不同物种对这些食物供应变化的反应在种群水平上已经有了很好的记录，但这些数据通常掩盖了个体反应中大量无法解释的变化。在这里，我们建议研究的发病率和影响的个体变异的资源利用北方塘鹅作为一个模型，广泛的海洋捕食者，饲料广泛的渔业丢弃物和远洋鱼类。个人的资源可利用性往往受到与其他种群成员竞争的强烈影响，但令人惊讶的是，迄今为止，很少有人试图将海洋捕食者对环境变化的反应置于依赖密度的资源利用模式的更广泛背景下。了解个人专业化的性质也有重要的保护意义，预测渔业和气候相关的变化的反应和可能的后果，顶端海洋捕食者。因此，在这个项目中，我们将：（一）涉及饮食专业化的塘鹅觅食地点，猎物搜索模式和捕获技术的个体差异;（二）研究人口水平的饮食广度和个人专业化的饮食和觅食行为的密度依赖的程度，和;（三）确定个体专业化的后果，为不同组成部分的生殖健康。除了回答有关通才捕食者种群内个体专门化的产生和维持的基本问题外，我们还将提供有关不同栖息地鸟类觅食范围和核心觅食区域的重要信息。这些数据将对保护主义者和决策者在欧洲沃茨确定重要鸟类区和建立海洋保护区方面具有重要价值。我们还将提供前所未有的详细信息，说明不同殖民地依赖渔业抛弃物的发生率和后果，以及小型浅水鱼类（如沙鳅）的重要性。这些信息对于准确预测欧洲渔业丢弃做法拟议变化对人口水平的影响以及与气候有关的对自然发生的饲料鱼的影响至关重要。

项目成果

Sexual segregation in a wide-ranging marine predator is a consequence of habitat selection

• DOI: 10.3354/meps11112
• 发表时间: 2015-01-07
• 期刊: MARINE ECOLOGY PROGRESS SERIES
• 影响因子: 2.5
• 作者: Cleasby, Ian R.;Wakefield, Ewan D.;Hamer, Keith C.
• 通讯作者: Hamer, Keith C.

Three-dimensional tracking of a wide-ranging marine predator: flight heights and vulnerability to offshore wind farms

• DOI: 10.1111/1365-2664.12529
• 发表时间: 2015-12-01
• 期刊: JOURNAL OF APPLIED ECOLOGY
• 影响因子: 5.7
• 作者: Cleasby, Ian R.;Wakefield, Ewan D.;Hamer, Keith C.
• 通讯作者: Hamer, Keith C.

Frequency and consequences of individual dietary specialisation in a wide-ranging marine predator, the northern gannet

广泛的海洋捕食者北方塘鹅个体饮食专门化的频率和后果

• DOI: 10.3354/meps12729
• 发表时间: 2018
• 期刊: Marine Ecology Progress Series
• 影响因子: 2.5
• 作者: Bodey T