Collaborative Research: Strike while the snake is hot: will increasing nighttime temperatures make an endothermic keystone species more susceptible to ectothermic predators?

捕食者和猎物之间的平衡是形成自然种群的根本力量。全球气温上升可能会扰乱关键物种的捕食者-猎物关系，从而对生态系统产生重大的间接影响。当两者中的一个是身体与环境温度基本一致的外温动物(如爬行动物)，另一个是保持相当恒定体温的吸热动物(如哺乳动物)时，发生这种影响的可能性最大。袋鼠是北美沙漠中的关键物种，它们觅食行为和种群生态的变化可能会在整个生态系统中层出不穷。响尾蛇是袋鼠的主要捕食者，它们的日常和季节性活动以及捕食行为直接与环境温度有关。这项建议结合了实验室和野外实验，全面记录了响尾蛇和袋鼠与温度有关的活动周期、行为和表现的细节。然后，这些信息将被用来开发计算机模拟模型，以了解温度如何通过捕食者和猎物相互作用动态的变化来调节捕食者和猎物之间的平衡。这些模型将使研究人员能够量化并实际预测气候变化对自然生态系统的复杂间接影响，从而产生广泛的保护影响。该项目还将产生广泛的社会影响，培训数十名来自不同背景的本科生和研究生，并通过在服务于经济困难人群的学校实施使用高速视频和生物力学的培训模块，激励高中生从事STEM职业生涯。捕食是一种基本的进化力量，塑造了捕食者和猎物的行为和形态的许多方面。由于捕食在大多数生物的生活中处于中心地位，捕食者-猎物的相互作用可以直接影响生态系统的结构和稳定性。然而，当生态学家研究捕食在群落结构中的作用时，很少考虑捕食者-猎物相互作用的详细机制。这些细节可能对于理解气候变化将如何影响关键物种的相互作用至关重要。这个项目的目标是全面评估环境温度升高破坏自然发生的温跃层中关键物种(响尾蛇和袋鼠)捕食者-猎物相互作用的可能性，然后使用这些数据来参数化和测试计算模型，以检验温度变化如何改变捕食者-猎物平衡。研究人员将进行一系列分层次的实验和分析，这些实验和分析将：(1)使用体内和体外实验室分析来量化温度对蛇的生理和肌肉骨骼系统功能的影响，肌肉骨骼系统用于为蛇的捕食性攻击提供动力。(2)采用实验室实验和野外实验相结合的方法，考察温度对全动物捕食行为的影响。(3)利用对不同纬度自然界中袋鼠和响尾蛇的详细直接观测，建立温度与体能、活动周期、觅食行为、运动生态和种群人口统计之间的基线关系。(4)使用与观测和实验数据校准的基于代理的计算模拟来预测不同热区的焦点种群动力学S。该奖项反映了美国国家科学基金会的法定使命，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。

The balance between predator and prey is a fundamental force shaping natural populations. Increasing global temperatures could have major indirect effects on ecosystems by disrupting the predator-prey relationships of keystone species. The potential for such an impact is greatest when one of the two is an ectotherm (such as a reptile) whose body largely conforms to the environmental temperature, and the other is an endotherm (such as a mammal) that maintains a fairly constant body temperature. Kangaroo rats are keystone species in North American deserts, and alterations in their foraging behavior and population ecology can cascade through the ecosystem. Rattlesnakes are major predators of kangaroo rats whose daily and seasonal activity and predatory performance is directly tied to the temperature of the environment. This proposal combines laboratory and field experiments that comprehensively document the details of the activity cycles, behaviors, and performance of rattlesnakes and kangaroo rats in relation to temperature. This information will then be used to develop computer simulation models of how temperature regulates equilibrium between predator and prey populations through changes in their interaction dynamics. These models will have broad conservation impacts by allowing researchers to quantify and actually predict complex indirect effects of climate change on natural ecosystems. This project will also have broad impacts on society by training several dozen undergraduate and graduate students from diverse backgrounds, and by inspiring high school students to pursue STEM careers through the implementation of training modules using high-speed video and biomechanics in schools that serve economically disadvantaged populations. Predation is a fundamental evolutionary force, shaping many aspects of behavior and morphology of predators and prey. Because of the centrality of predation in the lives of most organisms, predator-prey interactions can directly affect ecosystem structure and stability. However, the detailed mechanics of predator-prey interactions are rarely considered when ecologists examine the role of predation in structuring communities. Those details may be crucial in understanding how climate change will affect key species interactions. The objective of this project is to comprehensively evaluate the potential for increasing environmental temperature to disrupt predator-prey interactions in keystone species (rattlesnakes and kangaroo rats) across a naturally occurring thermal cline, and then use this data to parameterize and test computational models examining how temperature changes could alter predator-prey equilibria. Researchers will conduct a series of hierarchical experiments and analyses that will: (1) Use in vivo and in vitro laboratory analyses to quantify impacts of temperature on physiology and function of the musculoskeletal system used to power predatory strikes in snakes. (2) Combine laboratory and field experiments to examine the impact of temperature on whole-animal predatory performance. (3) Use detailed direct observation of kangaroo rats and rattlesnakes in nature at different latitudes to establish baseline relationships between temperature and physical performance, activity cycles, foraging behaviors, movement ecology, and population demographics. (4) Use agent-based computational simulations calibrated with observational and experimental data to predict focal population dynamics s across different thermal regimes.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.