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基本力量。全球气温上升可能会破坏关键物种的捕食关系，从而对生态系统产生重大的间接影响。当其中一方是体温很大程度上与环境温度相适应的变温动物（如爬行动物），而另一方是体温保持相当恒定的恒温动物（如哺乳动物）时，这种影响的可能性最大。袋鼠鼠是北美沙漠中的关键物种，它们的觅食行为和种群生态的变化可以在整个生态系统中产生连锁反应。响尾蛇是袋鼠鼠的主要捕食者，袋鼠鼠的日常和季节性活动和捕食行为与环境的温度直接相关。该提案结合了实验室和实地实验，全面记录了响尾蛇和袋鼠鼠的活动周期、行为和表现与温度的关系。这些信息将用于开发计算机模拟模型，以了解温度如何通过相互作用动态的变化来调节捕食者和猎物种群之间的平衡。这些模型将通过允许研究人员量化和实际预测气候变化对自然生态系统的复杂间接影响而产生广泛的保护影响。该项目还将培养数十名来自不同背景的本科生和研究生，并通过在为经济弱势群体服务的学校实施高速视频和生物力学培训模块，激励高中生追求STEM职业，从而对社会产生广泛影响。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命中处于中心地位，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构建群落中的作用时，很少考虑捕食者-猎物相互作用的详细机制。这些细节可能对了解气候变化如何影响关键物种的相互作用至关重要。该项目的目标是全面评估环境温度升高对关键物种（响尾蛇和袋鼠鼠）在自然发生的温跃带上破坏捕食者-猎物相互作用的潜力，然后使用这些数据来参数化和测试计算模型，以检查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实验和分析，其中包括：(1)使用体内和体外实验室分析来量化温度对生理和肌肉骨骼系统功能的影响，这些系统用于为蛇的掠食性攻击提供动力。(2)结合室内和野外实验，研究温度对全动物捕食性能的影响。(3)通过对不同纬度自然环境中袋鼠大鼠和响尾蛇进行详细的直接观察，建立温度与身体机能、活动周期、觅食行为、运动生态和种群统计之间的基线关系。(4)利用基于智能体的计算模拟，结合观测和实验数据进行校准，预测不同热环境下的焦点种群动态。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知识价值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.