Costs of Incubation: Linking Incubation-Induced Alterations in Phenotype to Changes in Fitness

蛋的孵化是鸟类繁殖的关键部分。 胚胎的最佳生长和发育发生在一个狭窄的孵化温度范围内，父母必须平衡保持良好身体状况的竞争需求，同时照顾发育中的卵子。 孵化的重要性往往被忽视的鸟类繁殖成本的研究，但孵化成本可以限制当前和未来的繁殖成功。 在只有一种性别孵化的物种中，时间和能量的需求尤其重要。 孵化父母的出勤率降低，使鸡蛋温度更有可能偏离最佳发育所需的温度。 低卵温会减缓发育并导致更长的孵化期，这会导致更大的捕食风险，并可能影响发育胚胎和最终新生儿表型所使用的能量。 这项研究与木鸭将有3个主要组成部分。 首先，以往的实验工作表明，孵化温度影响林鸭的孵化期和新生表型。本计画将利用孵卵温度来操控新生雏鸭之表型，然后将一日龄之雏鸭送回养母饲养。 这些温度诱导的变化对雏鸭表型的影响，对生长和发育，生存，繁殖种群的招募，以及随后的繁殖成功率将进行检查。 其次，研究了孵化温度对林鸭胚胎代谢率和总能量消耗的影响。 随后，还将研究不同温度下孵化的雏鸭的体温调节能力和体温调节的能量消耗。第三，孵化成本的成年人将被操纵和这些操纵成本的影响，体重动态，孵化行为，内和季节间的繁殖性能，和女性的生存将被检查。 该项目将使用一个生命史框架来研究产妇生殖决定的健康后果。 研究结果应该重新振兴孵化模式及其在鸟类的功能后果的研究，并作出新的贡献，我们的理解脊椎动物生活史的演变策略。研究与教育的结合将是该项目的一个重要目标。 这将通过以下方式实现：（1）将新的研究成果纳入本科生和研究生课程，（2）招募本科生和研究生参与该项目，（3）在萨凡纳河生态实验室为NSF赞助的本科生举办研讨会，以展示实地研究和数据管理方法，以及（4）整合K-12水禽繁殖活动，保护和教育与弗吉尼亚理工大学的科学推广计划（SOuP），使科学研究更广泛的受众，特别是K-12教师和学生。

Incubation of eggs is a critical part of reproduction in birds. Optimal growth and development of embryos takes place within a narrow range of incubation temperatures, and parents must balance the competing demands of maintaining good body condition while caring for developing eggs. The importance of incubation has often been overlooked in studies of avian reproductive costs, but incubation costs can limit both current and future reproductive success. Time and energy demands can be especially important in species where only one sex incubates. Reduced attendance by incubating parents makes it more likely that egg temperatures will deviate from that needed for optimal development. Low egg temperatures can slow development and lead to longer incubation periods, which results in greater predation risk and potentially influences the amount of energy used by developing embryos and ultimately neonate phenotype. This research with wood ducks will have 3 main components. First, previous experimental work has shown that incubation temperature influenced both incubation period and neonate phenotype of wood ducks. This project will use incubation temperature to manipulate phenotypes of neonates and then return day-old ducklings to foster mothers to raise. Effects of these temperature-induced changes to duckling phenotype on growth and development, survival, recruitment to the breeding population, and subsequent reproductive success will be examined. Second, effects of incubation temperature on metabolic rates and total energy expended by wood duck embryos will be estimated. Later, ability of ducklings incubated at different temperatures to thermoregulate and the energetic costs of thermoregulation also will be examined. Third, incubation costs of adults will be manipulated and effects of these manipulated costs on body mass dynamics, incubation behavior, within- and between-season reproductive performance, and survival of females will be examined. The project will use a life history framework to examine fitness consequences of maternal reproductive decisions. Results should re-invigorate studies of incubation patterns and their functional consequences in birds, and make new contributions to our understanding of the evolution of vertebrate life history strategies. Integration of research and education will be an important goal of the project. This will be accomplished by (1) incorporating new research findings in undergraduate and graduate courses, (2) recruiting undergraduate and graduate students to work on the project, (3) hosting a workshop for NSF-sponsored undergraduates at the Savannah River Ecology Laboratory to demonstrate field research and data management methods, and (4) integrating a K-12 activity on waterfowl reproduction, conservation and education with the Virginia Tech's Science Outreach Program (SOuP) which brings science research to broader audiences, especially K-12 teachers and students.