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，衡量成功(适合度)的关键标准是它们所产生的后代的数量，这些后代随后也会繁殖。在繁殖周期中运行的过程尤其会影响身体健康。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寄生等外部因素都是至关重要的。为了更好地理解为什么不同鸟类的健康状况不同，我的研究重点放在四个主要研究领域： (1)资源获取和分配：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，但对个体可用资源的缺乏阻碍了这一领域的进展。通过在空间合适的尺度(地区)上测量食物丰富度，以及操纵父母的工作效率，我们将提供亟需的洞察，以了解资源可获得性等环境因素如何推动父母的投资战略。 (2)质量指标：质量指标，如鸟类精致的羽毛颜色，被认为生产成本很高，但证明生产非色素为基础的颜色成本高昂一直是难以捉摸的。我将测试羽毛生长过程中的营养限制如何影响产生精细羽毛颜色的能力。此外，现在已经认识到，生命早期经历的条件会影响成年后的表现，实验和长期数据集将被用来探索出生条件如何影响成年后产生五颜六色羽毛的能力。 (3)父子关系模式：在社会性一夫一妻制的鸟类中，雌性经常在配偶关系之外交配，但这一点的好处尚不清楚。通过操纵在巢中感知到的孵化失败，然后在随后的繁殖尝试中测量额外配对父子的比率，我将测试这是否是雌性用来确保其卵子繁殖力的策略。 (4)宿主-寄生虫的相互作用：栖息在巢外的寄生虫对后代的生长和存活有不利影响，因此可以对健康产生重要影响，但我们对是什么导致巢间感染率的差异知之甚少。宿主的遗传多样性，无论是涉及免疫的特定基因，还是更普遍的整个基因组，都可能是对寄生虫抵抗力的一个重要决定因素。我将测试寄主的遗传多样性如何影响寄生虫利用它们的能力，进而影响寄生虫种群的大小。 我的研究将对鸟类的生殖生态学提供重要的见解，这对于理解随着环境条件的持续变化至关重要，并将为学生提供丰富的机会来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 parasitism are all critical. To better understand why fitness varies among individual birds, my research focuses on four major areas of study: (1) Resource Acquisition and Allocation: A key objective in evolutionary ecology is to understand how organisms allocate limited resources between reproduction and self-maintenance, but a lack of knowledge of the resources available to individuals has impeded progress in this area. By measuring food abundance on spatially appropriate scales (territories), and manipulating work rates of parents, we will provide much needed insight into how environmental factors such as resource availability drive parental investment strategies. (2) Indicators of Quality: Indicators of quality such as elaborate plumage colours in birds are thought to be costly to produce, but demonstrating that production of non-pigment based colour is costly has been elusive. I will test how nutrient limitation during feather growth influences the ability to produce elaborate plumage colour. Further, it is now recognized that conditions experienced early in life can impact performance during adulthood, and experiments and long-term data sets will be used to explore how natal conditions influence ability to produce colourful plumage as adults. (3) Patterns of Paternity: In socially monogamous birds, females often mate outside the pair bond but the benefits of this are unclear. By manipulating perceived hatching failure in nests and then measuring rates of extra-pair paternity in subsequent breeding attempts, I will test whether this is a strategy that females use for ensuring fertility of their eggs. (4) Host-Parasite Interactions: Nest-dwelling ectoparasites have detrimental effects on offspring growth and survival, and so can have important consequences for fitness, yet we know little about what drives variation in infestation rates among nests. Genetic diversity of hosts, both in terms of specific genes involved with immunity and more generally throughout the genome, can be an important determinant of resistance to parasites. I will test how genetic diversity of hosts influences the ability of parasites to exploit them, which in turn can influence size of parasite populations. My research will provide significant insights into the reproductive ecology of birds, which is vital to understand as environmental conditions continue to change, and will provide rich opportunities for students to solve critically important questions in evolutionary ecology and basic biology.