Collaborative Research: Climate Change, Cannibalism, and Reproductive Synchrony: The Effect of Food Shortages on Life History Strategies of Marine Organisms

与气候变化相关的更高温度可能导致海洋食物网的变化，导致顶级消费者的食物供应减少。作为回应，这些消费物种必须改变策略和行为以适应。在许多物种中观察到的一个变化是同类相食的增加。另一个是生育活动的时间。这种变化反过来又会导致整个生态系统发生一连串的变化，影响到个别物种的生存和整个系统的福祉。El Niño事件在短时间尺度上模拟了长期气候变化的一些特征，从而可以在海洋系统中测试一些与气候有关的假设。该项目将利用数学模型从理论上和经验上考察与气候变化相关的食物短缺对生物的影响，并以作为重要指示物种的大型海鸟种群为研究对象。这项工作将为本科生、硕士生和博士生提供数学生物学的跨学科培训。该项目强调培训本科生和来自代表性不足群体的成员。本科生将参与研究过程的每一个阶段，从数据收集和分析到共同撰写同行评审的出版物。调查人员通过公开讲座和访谈，以及与美国鱼类和野生动物管理局的生物学家和管理人员合作，吸引公众和野生动物管理人员。这项工作的结果对自然种群应对气候变化的管理具有重要意义。在以往的研究中，研究者证明：(1)海水表面温度升高与白羽鸥（Larus glaucescens）的食卵行为增加之间存在强烈的正相关关系，白羽鸥是海洋环境质量的重要指标；(2)白霜翅鸥每隔一天的排卵存在同步性，且同步性的程度与种群密度成正比。概念验证的数学模型表明，这两种特征可能是共同适应的，总的来说，上升的SSTs可能会引发殖民地海鸟生活史策略的一系列变化。本研究的目的是：(1)建立和分析一般数学模型，从种群和对食物可得性变化的适应性动态响应的角度探讨SSTs、环境食物可得性降低、同类相食和生殖同步的相互作用；(2)在一个特定的系统中，根据数学模型提出的两个一般假设，即：同类相食是对食物供应减少的适应性反应，这可能是海温增加的结果；生殖同步是对同类相食的适应性反应；(3)培养本科生、硕士和博士从事涉及数学建模和实地研究的跨学科STEM研究，有意强调对代表性不足群体的培养。

Higher temperatures associated with climate change can cause changes in marine food webs, resulting in a diminished food supply for top consumers. In response, these consumer species must change strategies and behaviors in order to adapt. One change that has been observed in numerous species is an increase in cannibalism. Another is the timing of reproductive activities. Such changes can in turn lead to a cascade of changes throughout an ecosystem, affecting survival of individual species and the well-being of the entire system. El Niño events mimic some features of long-term climate change on short time scales, allowing for tests of some climate-related hypotheses in marine systems. This project will examine the impact of climate-change-related food shortages on organisms both theoretically, using mathematical models, and empirically, at a large colony of seabirds that function as an important indicator species. The work will provide cross-disciplinary training in mathematical biology for undergraduate, masters, and Ph.D. students. The project emphasizes training undergraduates and members from underrepresented groups. Undergraduate students will be involved at every stage of the research process, from data collection and analysis to joint authorship of peer-reviewed publications. The investigators engage the general public and wildlife managers through public lectures and interviews, and by working with biologists and managers from the U.S. Fish and Wildlife Service. The results of this work have important implications for the management of natural populations responding to climate change.In previous work the investigators demonstrated (1) a strong positive association between rising sea surface temperatures (SSTs) and increased egg cannibalism in glaucous-winged gulls (Larus glaucescens), which are important indicators of marine environmental quality; and (2) the existence of every-other-day ovulation synchrony in glaucous-winged gulls, with the degree of synchronization proportional to colony density. Proof-of-concept mathematical models suggest that the two traits may be co-adaptive, and that, in general, rising SSTs may initiate a cascade of changes in life history strategies in colonial seabirds. The objectives of this study are to (1) develop and analyze general mathematical models for exploring the interaction of SSTs, reduced environmental food availability, cannibalism, and reproductive synchrony in terms of population and adaptive dynamic responses to changes in food availability; (2) field test, in a specific system, predictions associated with two general hypotheses suggested by the mathematical models, namely, that cannibalism is an adaptive response to decreased food supply, which can be a consequence of increased SST, and that reproductive synchrony is an adaptive response to cannibalism; and (3) train undergraduate, master's, and Ph.D. students in interdisciplinary STEM research involving mathematical modeling and field research, intentionally emphasizing the training of underrepresented groups.