DISSERTATION RESEARCH: Reproductive Senescence in the Florida Scrub-Jay (Aphelocoma coerulescens)

论文研究：佛罗里达灌丛鸦 (Aphelocoma coerulescens) 的生殖衰老

• 批准号: 0909620
• 负责人: Stephan Schoech
• 金额: $ 0.92万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0909620&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Reproductive; Senescence; Florida

A decrease in reproductive performance in older birds, despite the likely benefits of increased experience, is often attributed to senescence. Senescence is the progressive deterioration of structure and function over time, and in vertebrates is manifested as an age-related increase in mortality, decrease in fecundity, or both. The physiology of senescence is complex, and involves age-related changes in function of somatic and reproductive cells and tissues, and subsequent changes in interactions among these systems. Analyses of seventeen years of data from our study population of Florida Scrub-Jays (Aphelocoma coerulescens) reveals a quadratic relationship between breeder age and number of fledglings produced, with the youngest and oldest birds having the lowest reproductive success. The Florida Scrub-Jay is a cooperatively breeding passerine that is restricted to remnant scrub oak habitat of peninsular Florida. In this project, the investigators will assess reproductive aspects of senescence in this species; taking into consideration reproductive endocrinology, stress physiology, egg hatchability, sperm morphology, life history trade-offs, and age-related variance in parental behavior. Specifically, the investigators will conduct experiments to determine which component of the reproductive (hypothalamic-pituitary-gonadal: HPG) axis exhibits senescence by recording physiological changes (primarily endocrine measures) as individuals age. The results from this project which will combine observational and manipulative experiments will ultimately contribute valuable insight into the mechanisms that underlie (or are a result of) avian reproductive senescence. The broader impacts of the project will primarily be realized through the continuing education of a graduate student. The investigators will present and publish findings in appropriate national and international venues (e. g., at meetings and in respected journals). Similarly, both investigators regularly present research findings to lay organizations, such as ornithological and nature clubs.

尽管经验增加可能会带来衰老，但老龄鸟的生殖表现的下降通常归因于衰老。衰老是结构和功能随着时间的逐步逐步降低，在脊椎动物中，脊椎动物与年龄有关的死亡率增加，繁殖力降低或两者兼而有之。衰老的生理学很复杂，涉及与年龄相关的体细胞和生殖细胞和组织功能的变化，以及这些系统之间相互作用的随后变化。对佛罗里达州灌木jays（醋瘤凝聚菌）的研究人群的17年数据的分析揭示了育种者的年龄与产生的雏鸟数量之间的二次关系，最年轻和最古老的鸟类具有最低的生殖成功。佛罗里达州的灌木丛Jay是一种合作繁殖的雀形来，仅限于佛罗里达半岛的残留灌木橡木栖息地。在这个项目中，研究人员将评估该物种衰老的生殖方面。考虑到生殖内分泌学，压力生理，卵孵化性，精子形态，生活史权衡以及与年龄有关的父母行为差异。具体而言，研究人员将进行实验，以确定生殖（下丘脑 - 垂体 - 基达：HPG）轴的哪些成分通过记录生理变化（主要是内分泌测量），显示出衰老的衰老。该项目将结合观察性和操纵实验的结果最终将对鸟类生殖衰老的基础的机制有价值的见解。 该项目的更广泛影响将主要通过研究生的继续教育来实现。调查人员将在适当的国家和国际场所（例如，在会议和受人尊敬的期刊上）介绍并发表调查结果。同样，两位研究人员都定期向外行组织（例如鸟类学和自然俱乐部）介绍研究结果。