CAREER: Morphology, performance, and ecology of the endangered salt marsh harvest mouse and co-occurring wetland rodents

了解一个物种濒临灭绝的原因对其恢复计划至关重要。本研究结合野外和实验室的工作，研究了旧金山湾河口特有的濒临灭绝的盐沼收获鼠，以及它如何适应其湿地环境。居住在每天和季节性经历自然和控制洪水的栖息地，这一物种的个体受到持续的环境挑战，影响他们的行为。然而，人们对它们如何觅食、生存和繁殖知之甚少。此外，这些濒临灭绝的老鼠经常与其他啮齿动物共享这些栖息地，它们如何或是否避免与它们竞争尚不清楚。为了加深我们对这种濒危物种以及其他相关物种的生态和进化挑战的理解，该项目研究了个体在觅食和穿越栖息地时如何执行咬、攀爬和游泳等基本功能。由于这些功能受到解剖学的影响，因此我们分析了它们身体形态的重要方面的差异，如尾巴和四肢的长度、脚垫的大小和形状、头部的宽度和深度。表现和身体形态之间的关系为了解物种之间的身体差异是如何以及为什么进化提供了见解。了解形态和功能的变化对于预测盐沼收获鼠对栖息地管理措施和与气候变化相关的海平面上升的长期成功至关重要。将开设一门新的实地课程，以加利福尼亚suissun沼泽的生态学为中心，教授学生有市场的实地和定量技能，为研究项目提供数据，并逐渐了解和欣赏稀有和濒危物种的生态作用。本研究将形态学、生物力学、生态学和遗传学结合起来，研究濒临灭绝的盐沼收获鼠和其他共存的湿地啮齿动物在形态和行为上的差异对生态学的影响。在实验室中进行的进食和运动相关行为的形态学和运动学分析，将为盐沼收获鼠和其他湿地啮齿动物如何在不同基质的潜在冲突需求中导航以及它们如何分配资源提供见解。以实验室为基础的性能研究得到了解决特征适应价值的实地工作的补充：长期标记重新捕获研究，微生境特征的量化和遗传分析。结合基础科学和野生动物管理目标，这项工作有可能通过以下方式为野生动物管理政策提供信息：(1)确定盐沼收获鼠利用微生境和食物资源的生理能力的限制；(2)阐明不同湿地管理制度的适应性后果。加州州立大学圣马科斯分校（CSUSM）是一所西班牙裔服务机构，具有让代表性不足的学生参与各级学术研究的悠久传统。每个研究维度（形态学，性能，生态学和遗传学）都包含硕士论文项目的范围，并将为几名研究生提供资金。此外，CSUSM的本科生将在新提出的野外生态学课程中接受研究基础材料的教育。除了研究和教育之外，该项目还有能力通过会议演讲、科学出版物、媒体互动和社区STEM外展活动，向科学界内外的数百人宣传本地动物的重要性。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。

Understanding why a species is endangered is critical to planning for its recovery. Combining work in the field and in the laboratory, this study investigates the endangered salt marsh harvest mouse, endemic to the San Francisco Bay estuary, and how it is physically adapted to its wetland environment. Occupying habitats that experience natural and controlled flooding on daily and seasonal bases, individuals of this species are subjected to continual environmental challenges that impact their behavior. Yet little is known about how they manage to forage, survive, and reproduce. Furthermore, these endangered mice often share these habitats with other rodents, and it is not clear how or whether they avoid competing with them. To advance our understanding of the ecological and evolutionary challenges of this endangered species, and other related species, this project investigates how individuals perform basic functions of biting, climbing, and swimming as they relate to foraging and moving through their habitats. Because these functions are influenced by anatomy, differences in important aspects of their body form are analyzed, such as tail and limb lengths, foot pad size and shape, and head width and depth. The relationships between performance and body form provide insights into how and why physical differences among species have evolved. Understanding variation in form and function is imperative for predicting long-term success of salt marsh harvest mouse in response to habitat management practices and sea level rise associated with climate change. A new field course centered on the ecology of the Suisun Marsh, California, will be implemented to teach students marketable field and quantitative skills, to contribute data to the research project, and to instill an understanding and appreciation for the ecological roles of rare and endangered species.This study integrates morphology, biomechanics, ecology, and genetics to examine the ecological implications of differences in morphology and performance among the endangered salt marsh harvest mouse and other co-occurring wetland rodents. The proposed morphological and kinematic analyses of feeding- and locomotor-related behavior, performed in the laboratory, will provide insights into how salt marsh harvest mice and other wetland rodents navigate potentially conflicting demands of their diverse substrates and how they partition resources. The lab-based performance studies are complemented by work in the field that address the adaptive value of the traits: long-term mark-recapture studies, quantification of microhabitat characteristics, and genetic analyses. Integrating basic science and wildlife management objectives, this work has the potential to inform wildlife management policies by (1) identifying limitations to the salt marsh harvest mouse’s physical abilities to use microhabitat and food resources and (2) illuminating the adaptive consequences of different wetland management regimes. California State University San Marcos (CSUSM) is a Hispanic Serving Institution with a strong tradition of involving underrepresented students in all levels of academic research. Each of the study dimensions (morphology, performance, ecology, and genetics) encompasses the scope of a master’s thesis project, and funding will be provided for several graduate students. Moreover, CSUSM undergraduate students will be educated on the study’s foundational material in the newly proposed field ecology course. Beyond research and education, this project has the capacity to reach hundreds more, both inside and outside of the scientific community, through conference presentations, scientific publications, media interactions, and community STEM outreach activities highlighting the importance of native fauna.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.