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.

老年鸟类繁殖能力的下降，尽管增加经验可能有好处，但通常归因于衰老。衰老是结构和功能随着时间的推移而逐渐退化，在脊椎动物中表现为与年龄相关的死亡率增加，繁殖力下降或两者兼而有之。衰老的生理学是复杂的，并且涉及体细胞和生殖细胞和组织的功能的与年龄相关的变化，以及这些系统之间的相互作用的后续变化。从我们的研究人口的佛罗里达灌丛鸦（Aphelocoma coerulescens）的17年的数据分析揭示了繁殖年龄和幼鸟产生的数量之间的二次关系，与最年轻和最老的鸟类具有最低的繁殖成功率。佛罗里达灌丛鸦是一种合作繁殖雀形目，仅限于佛罗里达半岛的残余灌丛橡树栖息地。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，应激生理学，卵子孵化率，精子形态学，生活史权衡以及与年龄相关的父母行为差异。具体来说，研究人员将进行实验，以确定生殖（下丘脑-垂体-性腺：HPG）轴的哪一部分通过记录生理变化（主要是内分泌测量）随着个体年龄的增长而衰老。该项目的结果将结合联合收割机的观察和操作实验，最终将有助于有价值的洞察机制的基础（或结果）鸟类生殖衰老。 该项目更广泛的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：例如，在一个实施例中，在会议和受人尊敬的期刊上）。同样，这两名研究人员定期向鸟类学和自然俱乐部等非专业组织展示研究成果。