LTREB: The Ecological and Organismal Basis for Early-Season Life History Variation in Tree Swallows Tachycineta Bicolor

LTREB：树燕 Tachycineta Bicolor 早季生活史变异的生态和有机基础

• 批准号: 0131437
• 负责人: David Winkler
• 金额: $ 29.8万
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0131437&HistoricalAwards=false
• 关键词: LTREB; Ecological; Organismal; Basis; Early

This project is to extend and upgrade a long-term study of the ecology and reproductive biology of tree swallows (Tachycineta bicolor) nesting near Ithaca, New York. This population numbers approximately 300 breeding pairs. The population has been studied for the past fifteen years, and a large number of techniques have been developed to efficiently explore tree swallow biology and ecology. Many of these techniques take advantage of the fact that tree swallows readily nest in artificial nest-boxes. Like many other songbirds, tree swallows have about a 50% annual survival rate, so a five year study can sample many birds during their entire reproductive lifetimes. Tree swallows are obligate aerial insectivores. Thus, they are unusually sensitive to short-term changes in weather, because their prey, flying insects, are unable to fly during cool temperatures or rain. Previous research has developed the methods for sampling and analyzing insect availability on a daily basis. One of the principal foci of the research in Ithaca in the past ten years has been investigating the seasonal decline of clutch size. Earlier laying females lay larger clutches, and they pay no measurable cost for laying earlier. Tree swallows across North America have advanced their date of laying, apparently in response to global climate change, and understanding the determinants and consequences of lay-date variation is thus of both basic and applied interest. The current project would attempt to answer three related questions: 1) How does variation in insect abundance and weather affect the lay-dates of individual swallows? 2) Does variation in flight performance correlate with variations in lay-date and chick-provisioning performance? 3) What are the consequences of short-term variation in weather and food supply both in terms of organismal biology and breeder fitness? Flight performance is clearly a critical trait for an aerial insectivore, and it will be evaluated in a Flight Performance Test Tunnel that is already constructed and in need of only slight modifications. Chick-provisioning performance will be assessed through a series of detailed behavioral observations coupled with samples of the food being delivered to the chicks collected in a specially developed trap. Physiological health and stress will be evaluated with repeated measurements of blood characteristics. This project would bring a new level of detailed measurements to a long-term study that has proved its worth both in basic research output and in education of students at all levels. By studying swallow reactions to the dynamic weather conditions of a temperate ecosystem, we can better understand the relationships between an animal's biology and its environment, both today and in the past, and make better predictions about how environmental changes will affect animal populations.

该项目是为了扩大和升级对纽约伊萨卡附近筑巢的树燕（Tachycineta bicolor）的生态学和生殖生物学的长期研究。 这一种群大约有300对繁殖后代。 在过去的15年里，人们一直在研究该种群，并开发了大量技术来有效地探索树燕生物学和生态学。 这些技术中的许多技术利用了树燕容易在人工巢箱中筑巢的事实。 像许多其他鸣禽一样，树燕的年存活率约为50%，因此一项为期五年的研究可以在整个繁殖期内对许多鸟类进行采样。树燕是专性空中食虫动物。 因此，它们对天气的短期变化异常敏感，因为它们的猎物，飞行昆虫，在凉爽的温度或下雨时无法飞行。 以前的研究已经开发了每天采样和分析昆虫可用性的方法。 在过去的十年里，伊萨卡岛研究的主要焦点之一是调查窝卵数的季节性下降。 较早产卵的雌性会产下更大的窝，而且它们不会因为较早产卵而付出可衡量的代价。 北美的树燕提前了它们的产卵日期，显然是为了应对全球气候变化，因此了解产卵日期变化的决定因素和后果具有基本和应用价值。 目前的项目将试图回答三个相关的问题：1）昆虫丰度和天气的变化如何影响个体燕子的产卵日期？2)飞行性能的变化是否与产蛋日期和雏鸡供应性能的变化相关？3)天气和食物供应的短期变化对生物学和繁殖者的适应性有什么影响？ 飞行性能显然是空中食虫动物的一个关键特征，它将在一个已经建成的飞行性能测试隧道中进行评估，只需要稍微修改。将通过一系列详细的行为观察以及在专门开发的陷阱中收集的运送给小鸡的食物样本来评估小鸡的供应性能。将通过重复测量血液特性来评估生理健康和压力。该项目将为长期研究带来一个新的详细测量水平，该研究已证明其在基础研究成果和各级学生教育方面的价值。 通过研究燕子对温带生态系统的动态天气条件的反应，我们可以更好地了解动物的生物学和环境之间的关系，无论是现在还是过去，并更好地预测环境变化将如何影响动物种群。