BRC-BIO: Looking beyond the calorie: Nutritional ecology in a generalist predator

BRC-BIO：超越卡路里：通才捕食者的营养生态学

• 批准号: 2312718
• 负责人: Allison Cornell
• 金额: $ 48.62万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2312718&HistoricalAwards=false
• 关键词: BRC; BIO; Looking; beyond; calorie

Calories are often treated as the primary unit of nutrition, but a growing body of evidence suggests that the specific nutrient composition of food may be a more important driver of foraging behavior in wildlife. Because nutrient composition varies with environmental conditions, climate change is likely to affect nutrient content of food. For predators, this means that a changing climate could alter the nutrition of their prey, and therefore, what prey they select. However, without baseline knowledge of how nutrients shift in response to changing environmental conditions, it is difficult to make predictions about predator behavior. Songbirds are common predators in many ecosystems that prey on a variety of insects and can easily be captured and observed for behavioral studies. This project will 1) assess macronutrients (protein, carbohydrate, lipid) in prey and identify specific ratios of macronutrients that maximize nestling growth, 2) examine how the nutritional value of prey changes when reared in experimentally manipulated environmental conditions, and 3) examine whether changes in nutrition affect birds’ preference for prey. Because insects are consumed by many animals outside of birds, this work will have conservation implications for a wide range of taxa. The research team will include undergraduate students enrolled in relevant biology courses and paid undergraduate assistants. Students will develop independent projects related to the broader theme and travel to national conferences to present their work. This research experience will equip participants with skills in laboratory and field work and build students’ confidence to persist in STEM careers. Using a combination of manipulative laboratory experiments and an existing network of 100 Eastern bluebird nest-boxes, the researchers will examine how environmental conditions affect prey nutrient composition and whether these changes impact predator preference. This work will test the use of the nutritional geometric framework: a tool for assessing nutrition by utilizing ratios of nutrients to model how foods are combined to reach multidimensional nutritional targets that maximize organism performance. This framework is useful in modeling how diet changes as different food items change in availability or quality. By measuring the impact of prey macronutrients on nestling development in Objective 1, the researchers will identify multidimensional nutritional targets that maximize growth in nestlings. In Objective 2, these data will be used to test whether the environmental conditions of prey meaningfully impact their nutrient content. Although some studies investigate how nutrients change in response to temperature or diet shifts, very few examine these in combination, even though climate change is predicted to simultaneously affect both. Experiments in Objective 2 manipulating diet and rearing temperature will advance our understanding of how multiple environmental changes interact to determine nutritional value. Finally in Objective 3, researchers will examine bluebird nutritional preferences using field-based choice assays with nutritionally altered insect prey. The experiments in this project will advance basic science of nutritional ecology by examining hypotheses from the nutritional geometric framework and life history theory, the outcomes of which will inform conservation applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

卡路里通常被视为主要的营养单位，但越来越多的证据表明，食物的特定营养成分可能是野生动物觅食行为的更重要驱动因素。由于营养成分随着环境条件的变化而变化，气候变化可能会影响食物的营养含量。对于捕食者来说，这意味着气候变化可能会改变猎物的营养，从而改变他们选择的猎物。然而，如果没有营养物质如何随着环境条件的变化而变化的基线知识，就很难对捕食者的行为做出预测。鸣禽是许多生态系统中常见的捕食者，它们捕食各种昆虫，很容易被捕获并观察以进行行为研究。该项目将1)评估猎物中的常量营养素(蛋白质、碳水化合物、脂肪)，并确定最大限度地促进雏鸟生长的常量营养素的特定比例，2)研究在实验操作的环境条件下饲养的猎物的营养价值如何变化，以及3)检查营养变化是否影响鸟类对猎物的偏好。由于昆虫被鸟类以外的许多动物吃掉，这项工作将对广泛的分类群产生保护意义。研究团队将包括注册相关生物课程的本科生和带薪的本科生助理。学生们将开发与更广泛的主题相关的独立项目，并前往全国会议介绍他们的工作。这一研究经验将使参与者掌握实验室和实地工作的技能，并建立学生坚持STEM职业生涯的信心。利用操纵性实验室实验和现有的100个东部蓝鸟巢箱网络，研究人员将研究环境条件如何影响猎物的营养成分，以及这些变化是否会影响捕食者的偏好。这项工作将测试营养几何框架的使用：一种评估营养的工具，通过利用营养比率来模拟食物是如何组合在一起的，以达到最大限度地提高机体性能的多维营养目标。这个框架在模拟饮食如何随着不同食物的可获得性或质量的变化而变化时很有用。通过在目标1中衡量猎物大量营养素对雏鸟发育的影响，研究人员将确定多维营养目标，使雏鸟的生长最大化。在目标2中，这些数据将被用来测试猎物的环境条件是否对其营养含量产生有意义的影响。尽管一些研究调查了营养素如何随温度或饮食变化而变化，但很少有人将它们结合在一起研究，尽管气候变化预计会同时影响这两个因素。在目标2中操纵饮食和饲养温度的实验将增进我们对多种环境变化如何相互作用来确定营养价值的理解。最后，在目标3中，研究人员将对营养变化的昆虫猎物进行实地选择分析，以检验蓝鸟的营养偏好。该项目中的实验将通过检验营养几何框架和生活史理论中的假设来推进营养生态学的基础科学，其结果将为保护应用提供信息。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。