Reproductive Effort and Success in Birds

生物体生活在一个不确定和具有挑战性的世界中，成功（适应性）的关键衡量标准是它们产生的后代的数量，这些后代随后也繁殖。在繁殖周期中运行的过程尤其会影响适应性。例如，在鸟类中，选择合适的配偶，为后代分配能量和营养，以及环境条件等外部因素都是至关重要的。为了更好地理解为什么个体之间的适应性不同，我的研究将集中在三个主要领域：（1）鸟类生活史策略对环境变化和随机性的敏感性：进化生态学的一个关键目标是了解生物如何在繁殖和自我维持之间分配有限的资源，但导致最高个体适应性的策略是动态的，取决于它们发生的环境背景。使用树燕和山蓝知更鸟，我们将测试如何可变的条件和需求影响父母的决定，投资在后代与自我维护，如何解决冲突的最佳水平的父母照顾，以及这些决定的后果后代的表现。(2)纳塔尔条件对成体表型和适应性的影响：生物体的表型是基因型和环境之间的复杂相互作用，早期生活条件对成体表型和性能具有重要和持久的影响。此外，越来越多的证据表明，早期生活条件也会影响后代，但这些影响在自然界中的普遍程度基本上是未知的。利用树燕和山蓝知更鸟的长期数据，我们将测试个体的纳塔尔条件如何影响终生生殖成功和成年表型，以及它们是否是跨代的，并会影响后代的表现。(3)微塑料污染：微塑料是风化聚合物的小碎片，以及个人护理产品中的微珠和洗涤衣物中的合成纤维，它们在污水中释放到环境中，对许多生态系统构成潜在的全球威胁。我们将评估微塑料是否在食物网中转移，以及它们对食虫鸟类等更高营养级生物的影响。这项研究将阐明食虫鸟类暴露于微塑料的程度，并可能有助于确定这类鸟类种群数量下降的可能原因。我的研究将提供重要的见解鸟类的生殖生态学，这是至关重要的了解环境条件不断变化，变得越来越多变，并将提供丰富的机会，让学生解决进化生态学和基础生物学中至关重要的问题。

Organisms live in an uncertain and challenging world where the critical measure of success (fitness) is the number of progeny they produce that subsequently also reproduce. Processes operating during the breeding cycle can especially influence fitness. In birds, for example, choice of an appropriate mate, allocation of energy and nutrients to offspring, and external factors such as environmental conditions are all critical. To better understand why fitness varies among individual birds, my research will focus on three major areas of study: (1) Sensitivity of Avian Life-History Strategies to Environmental Change and Stochasticity: A key objective in evolutionary ecology is to understand how organisms allocate limited resources between reproduction and self-maintenance, but the strategies that result in the highest individual fitness are dynamic and depend on the environmental context in which they occur. Using tree swallows and mountain bluebirds, we will test how variable conditions and demands influence parental decisions regarding investment in offspring versus self-maintenance, how the sexes resolve conflicts over optimal levels of parental care, and the consequences of these decisions for offspring performance. (2) Effects of Natal Conditions on Adult Phenotype and Fitness: An organism's phenotype is a complex interaction between genotype and environment, and early life conditions can have important and lasting effects on adult phenotype and performance. Moreover, evidence is growing that early life conditions can also affect subsequent generations, but the prevalence of these effects in nature is largely unknown. Using long-term data on tree swallows and mountain bluebirds, we will test how natal conditions of individuals influence lifetime reproductive success and adult phenotype, and whether they are transgenerational and carry over to influence performance of subsequent generations. (3) Microplastic Pollution: Microplastics are small fragments of weathered polymers, as well as microbeads from personal care products and synthetic fibres from clothes washing released to the environment in sewage, and are a potential global threat to many ecosystems. We will assess whether microplastics are transferred within food webs, and their effects on higher trophic level organisms such as insectivorous birds. This research will clarify the degree to which insectivorous birds are exposed to microplastics, and may help identify possible causes of population declines in this group of birds. My research will provide significant insights into the reproductive ecology of birds, which is vital to understand as environmental conditions continue to change and become increasingly variable, and will provide rich opportunities for students to solve critically important questions in evolutionary ecology and basic biology.