A new theory of clutch size evolution: Consequences of morphology at fledging on mobility and survival interacting with parental energy expenditure (FMR)

窝数进化的新理论：雏鸟形态对活动性和生存的影响与父母能量消耗（FMR）相互作用

• 批准号: 1349178
• 负责人: Thomas Martin
• 金额: $ 53.65万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-15 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1349178&HistoricalAwards=false
• 关键词: new; theory; clutch; size; evolution

How hard should parents work to raise offspring, and how does this work effort influence the number and survival of offspring that parents attempt to raise? These are questions that have intrigued scientists for more than a century, and have major implications for population dynamics of wild animals. These questions have been highlighted among songbirds because species vary extensively in the number of young that parents attempt to raise. Even among species that breed in the same habitat, such as high elevation riparian habitat in Arizona where work will be conducted, species vary extensively in the number of offspring they attempt to raise. For example, a green-tailed towhee in that habitat typically lays 3 or 4 eggs, a red-faced warbler lays 4 or 5 eggs, while a mountain chickadee may lay 8 eggs. A new theory to explain this variation based on risk of mortality to offspring and parents is proposed and this grant will fund tests of the new theory. Species differ in the risk of their young being eaten by predators, with the open cup nests of the towhee or warbler experiencing high predation, while the cavity nests of chickadees experience very low risk of predation. These differences in predation risk affect how long the young stay in the nest; species like the towhee and warbler leave their risky nest 8 to 11 days after hatch, while chickadees do not leave their safe cavity nest until 20 to 22 days after hatch. As a result, the towhee and warbler young cannot fly when they leave their nest, while the chickadees are fully flight capable when they leave. These differences in developmental state of the young when they leave the nest also potentially affect how quickly they start feeding themselves, with the chickadees potentially feeding themselves within a few days after leaving the nest, while the towhee may take 3 weeks to develop this ability. Potentially, towhee parents must work much harder for each young to provide all their food compared with the chickadee where young almost immediately start obtaining some of their own food and can follow parents to reduce their travel. The extent to which parents are willing to work differs among species depending on their risk of mortality over their annual cycle. Taken together, these effects may explain why species differ in the number of young they attempt to raise, and has critical consequences for population dynamics of species. The proposed work will use observational and experimental approaches to testing these hypotheses.The fledgling period (after offspring leave the nest) is a critical period for demography, but interspecific variation in survival is unknown and documentation will aid understanding of population vulnerabilities to changing environmental conditions. Given the documented economic and aesthetic importance of birding to society, this conservation knowledge is important. Three graduate students whose thesis research will be supported by this project will be trained. Each year, 1 technician and 6 undergraduates will be trained in field techniques and the conduct of science, as well as 8 undergraduates from across disciplines (in and outside of biology) to transcribe videos of parental behaviors. The latter provides outreach to engage diverse students in scientific principles. Students will be educated through discussion sessions that will be used to teach the scientific principles for the work being conducted. To identify possible recruits, we will use broad advertising approaches to further enhance the diversity of social and cultural groups from which we can recruit. Finally, nests provide a rich source of video opportunities to demonstrate differences among species in social interactions, as well as intriguing videos of predation events. The researcher started obtaining short, high definition videos to develop an educational series on parental and offspring behaviors and predation events to put on YouTube for public outreach. PBS Nature is filming a documentary on nest architecture and avian family life that will include footage at the focal field site to further increase public outreach.

父母应该如何努力提高后代，这项工作的努力如何影响父母试图提高的后代的数量和生存？ 这些问题吸引了科学家一个多世纪，并且对野生动物的种群动态具有重大影响。 这些问题在鸣禽中得到了强调，因为物种在父母试图养育的年轻人数量上差异很大。即使在同一栖息地繁殖的物种中，例如在亚利桑那州进行工作的高海拔河岸栖息地，物种在试图饲养的后代数量上也有很大不同。 例如，该栖息地中的绿尾拖曳通常产下3或4个鸡蛋，一个红面的莺将4或5个鸡蛋产下4或5个鸡蛋，而山山雀可以产下8个鸡蛋。 提出了一种基于对后代和父母的死亡风险来解释这种变化的新理论，该赠款将资助新理论的测试。 物种在捕食者食用年轻的风险上有所不同，to虫或莺的开放杯巢经历了高掠食，而山雀的腔巢则经历了非常低的捕食风险。 捕食风险的这些差异会影响年轻人在巢中的时间。孵化后8至11天，像Towhee和Warbler这样的物种将其危险的巢留下，而山雀直到孵化后20至22天才离开安全的腔巢。 结果，当山雀离开巢穴时，山雀和鸣鸟年轻人无法飞行，而山雀在离开时完全有能力飞行。 这些年轻人离开巢穴时的发育状态差异也有可能影响他们开始自我养活的速度，而山雀在离开巢穴后的几天内有可能在养活自己的情况下养活自己，而山雀可能需要3周的时间才能发展出这种能力。 与山雀（Chickadee）相比，towhee父母必须为每个年轻人提供所有食物的努力，在那里年轻的年轻人几乎立即开始获得自己的一些食物，并可以跟随父母减少旅行。 父母愿意在物种之间愿意工作的程度取决于其在年周期中死亡的风险。 综上所述，这些影响可以解释为什么物种在试图养育的年轻人的数量上有所不同，并且对物种的种群动态产生了关键后果。 拟议的工作将使用观察和实验方法来检验这些假设。刚起步的时期（后代离开巢穴后）是人口统计学的关键时期，但生存的种间变化尚不清楚，文档将有助于理解人口脆弱性，使人们了解改变环境状况的变化。鉴于观鸟对社会的经济和审美的重要性，这种保护知识很重要。将对该项目的论文研究的三名研究生将受到培训。每年，有1名技术人员和6名本科生将接受现场技术和科学的行为，以及来自各个学科（在生物学的内外）的8个本科生，以转录父母行为的视频。后者提供了宣传，使各种学生参与科学原则。将通过讨论会议对学生进行教育，该会议将用于教授所进行工作的科学原则。为了确定可能的新兵，我们将采用广泛的广告方法来进一步增强我们可以从中招募的社会和文化团体的多样性。最后，巢提供了丰富的视频机会来源，以展示社交互动中物种之间的差异，以及有趣的捕食事件视频。研究人员开始获得简短的高清视频，以开发有关父母和后代行为和捕食事件的教育系列，以供YouTube进行公共宣传。 PBS Nature正在拍摄有关巢建筑和鸟类家庭生活的纪录片，其中将包括焦点场地的镜​​头，以进一步增加公众的外展。