DISSERATION RESEARCH: Life History Trade-offs: An Investigation of the resource allocation hypothesis in the Florida Scrub-Jay (Aphelocoma coerulescens)

论文研究：生活史权衡：佛罗里达灌丛鸦 (Aphelocoma coerulescens) 资源分配假说的调查

• 批准号: 0508418
• 负责人: Stephan Schoech
• 金额: --
• 依托单位: University of Memphis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0508418&HistoricalAwards=false
• 关键词: DISSERATION; RESEARCH; Life; History; Trade

Dissertation Research: Life History Trade-offs - An investigation of the resource allocation hypothesis in the Florida Scrub-Jay (Aphelocoma coerulescens) Stephan J. Schoech & Raoul K. BoughtonUniversity of MemphisThere is considerable interest in the hypothesized trade-off between current reproductionand survival. However, the mechanisms that mediate this trade-off have been elusive. One mechanism that can affect both reproduction and survival is the immune system. While activation of the immune system during reproduction will likely increase survival, activation will also use energetic resources that could have been directed towards reproduction. The main objectives of this study are to test the resource allocation hypothesis in the monogamous long-lived cooperatively breeding Florida Scrub-Jay, and to investigate endocrine mechanisms that may function as immuno-modulators. Florida Scrub-Jays are a unique model to investigate the resource allocation hypothesis because research in this area has been restricted to migratory species with life histories that are characterized by relatively short life spans and temporally restricted breeding seasons. The sedentary nature, long life span, and socially and genetically monogamous breeding system of the Florida Scrub-Jay provide for a new and unique model to investigate postulated reproduction-survival trade-offs. The study has five specific objectives: (1) To characterize immune responses throughout the yearly cycle with special attention paid to previously identified energetic bottleneck periods when an internal trade-off of resources would be expected to occur; (2) To measure the effects of high quality supplemental food on immune function and reproductive success by comparing jays from supplemented and non-supplemented territories; (3) To determine whether breeding per se is responsible for immune suppression by comparing immune responses in breeders and nonbreeding helpers; (4) To further investigate the interrelationship between immune function and endocrine physiology (especially, testosterone, estrogen, corticosterone, and prolactin); and (5) to monitor both disease and parasite state to assess their effects upon immune function, reproductive effort, and survival. The broader impacts of this study are numerous and include facilitating co-PI Boughton's graduate training as both a professional researcher and as a mentor to undergraduate students. Where possible, we will recruit undergraduate students from the Department of Biology, University of Memphis' NSF funded program, Undergraduate Mentoring in Environmental Biology. These students will have the opportunity to learn methods and techniques of field biology, such as bird handling, blood sampling, and assays of immune function. Researchers will be exposed to the general public while working on the suburban portions of Florida Scrub-Jay population, allowing direct communication as to how basic science can investigate the reproductive success, disease exposure, and coping mechanisms of this threatened species. The grass roots concept of public awareness of research programs and the research that is undertaken is fundamental to encourage continued public support of funding programs. Additionally, both co-PIs regularly share their research results with local birding clubs and within the classroom at the University of Memphis. A most important aspect of this study is its connection with the private Archbold Biological Station and the long term Florida Scrub-Jay research. This relationship has promoted a partnership with another PhD student from the University of Missouri at St. Louis, who is concurrently investigating the oxygen free radical hypothesis and how it relates to longevity. The combined efforts of both studies will allow evaluation of two hypotheses put forth to explain why immune suppression may occur during reproduction.

论文研究：生活史权衡-对佛罗里达灌木- jay （Aphelocoma coerulescens）资源分配假说的调查Stephan J. Schoech & Raoul K. BoughtonUniversity of孟菲斯有相当大的兴趣在当前繁殖和生存之间的假设权衡。然而，调解这种权衡的机制一直难以捉摸。免疫系统是影响生殖和生存的一种机制。虽然在繁殖过程中激活免疫系统可能会提高存活率，但激活免疫系统也会消耗本来可以用于繁殖的能量资源。本研究的主要目的是在一夫一妻制长寿命合作繁殖的佛罗里达灌木-杰伊身上验证资源分配假说，并探讨可能作为免疫调节剂的内分泌机制。佛罗里达灌丛鸦是研究资源分配假说的一个独特模型，因为该领域的研究仅限于具有相对较短寿命和暂时限制繁殖季节的生活史的迁徙物种。佛罗里达灌木松鸦的久坐性、长寿命以及社会和遗传上的一夫一妻制繁殖系统为研究假设的繁殖-生存权衡提供了一个新的独特模型。该研究有五个具体目标：(1)在整个年度周期中表征免疫反应，特别关注先前确定的能量瓶颈期，此时预计会发生内部资源权衡；(2)通过比较添加区和未添加区的雏鸟，考察优质添加物对雏鸟免疫功能和繁殖成功率的影响；(3)通过比较育种者和非育种辅助者的免疫反应，确定育种本身是否对免疫抑制负有责任；(4)进一步研究免疫功能与内分泌生理（尤其是睾酮、雌激素、皮质酮、催乳素）的相互关系；(5)监测疾病和寄生虫状态，评估其对免疫功能、繁殖努力和生存的影响。这项研究的更广泛的影响是多方面的，包括促进博顿作为专业研究员和本科生导师的研究生培训。在可能的情况下，我们将招收来自孟菲斯大学生物系的本科生，这是美国国家科学基金会资助的项目，本科生环境生物学指导。这些学生将有机会学习野外生物学的方法和技术，如鸟类处理、血液采样和免疫功能测定。研究人员在研究佛罗里达灌木杰伊种群的郊区部分时，将与公众接触，以便直接交流基础科学如何调查这种受威胁物种的繁殖成功率、疾病暴露和应对机制。公众对研究项目和所进行的研究的意识的基层概念是鼓励公众继续支持资助项目的基础。此外，两位合作伙伴定期与当地观鸟俱乐部和孟菲斯大学的课堂上分享他们的研究成果。这项研究的一个最重要的方面是它与私人阿奇博尔德生物站和佛罗里达灌木杰伊长期研究的联系。这种关系促使他与密苏里大学圣路易斯分校的另一名博士生建立了合作关系，他同时也在研究氧自由基假说及其与长寿的关系。两项研究的共同努力将允许评估提出的两个假设，以解释为什么免疫抑制可能发生在生殖过程中。