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

了解物种濒临灭绝的原因对于计划物种的恢复至关重要。结合野外和实验室的工作，这项研究调查了旧金山湾口特有的濒危盐沼收获鼠，以及它是如何适应其湿地环境的。栖息地每天和季节都经历自然和受控的洪水，该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，目前尚不清楚它们如何或是否避免与它们竞争。为了促进我们对这种濒危物种和其他相关物种的生态和进化挑战的理解，这个项目调查了个体在觅食和在栖息地移动时如何执行咬人、攀登和游泳的基本功能。因为这些功能受解剖学的影响，所以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，以及头的宽度和深度。表现和身体形态之间的关系提供了洞察物种之间的身体差异是如何以及为什么进化的洞察力。了解形态和功能的变化对于预测盐沼捕鼠在应对与气候变化相关的栖息地管理做法和海平面上升方面的长期成功是至关重要的。将实施一门新的野外课程，以加利福尼亚州绥孙沼泽的生态学为中心，向学生传授适销对路的野外和定量技能，为研究项目提供数据，并灌输对稀有和濒危物种的生态作用的理解和欣赏。本研究结合形态学、生物力学、生态学和遗传学，研究濒危盐沼收获鼠和其他共生湿地啮齿动物在形态和表现上的差异的生态学意义。拟议的在实验室进行的与觅食和运动相关的行为的形态和运动学分析，将为盐沼收获的老鼠和其他湿地啮齿动物如何驾驭对其不同底物的潜在冲突需求以及它们如何分配资源提供洞察力。以实验室为基础的性能研究得到了实地工作的补充，这些工作涉及性状的适应价值：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身体能力的限制；(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)是一所拉美裔服务机构，有着让代表不足的学生参与所有水平的学术研究的深厚传统。每个研究维度(形态、性能、生态学和遗传学)都包括一个硕士论文项目的范围，并将为几个研究生提供资金。此外，南加州州立大学本科生将在新开设的田野生态学课程中接受有关研究基础材料的教育。除了研究和教育，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外联活动，接触到科学界内外的数百人，突出本土动物群的重要性。该奖项反映了NSF的法定使命，并通过使用基金会的智力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.