Doctoral Dissertation Improvement Grant: Foraging Ecology of Delacour's Langurs in a Harsh Environment

delacouri Trachypithecus delacouri生活在越南一个异常恶劣的环境中，它们在那里移动并以粗糙的、植被稀少的喀斯特（石灰岩）地层为食。这些非凡的、极度濒危的灵长类动物几乎没有被研究过，人们对喀斯特森林的摄食生态知之甚少。这项研究将为土壤质量、植物化学和食物选择之间的动态关系提供数据，也就是说，食草哺乳动物如何平衡它们的营养需求和它们所吃的植物性食物中存在的有毒化合物。土壤影响着植物的化学性质。草食动物根据这些植物成分以及获取食物的功效来决定摄食和运动。在食物有限的栖息地中，食叶猴受到具有挑战性的基质和导致植被发育不良的恶劣土壤条件的限制，这一事实对适应具有重要意义。虽然有大量证据表明食草灵长类动物在其他类型的环境中如何做出摄食决定，但没有证据表明什么因素影响喀斯特栖息地的摄食决定。在地理和食物有限的环境中，确定土壤类型、植物防御化合物和基质有效性对德拉库尔叶猴觅食的作用，对所有灵长类动物的运动和饮食适应具有深远的意义。此外，该项目将阐明这些猴子以及一般食草动物如何适应喀斯特假定的低资源环境。土壤、树叶和行为分析将用于分析越南北部一个孤立的喀斯特山区两组自由放养的德拉库尔叶猴的食物选择。这些数据将用于评估资源可用性假设，即植物在植物生长资源有限的环境中大量投资防御。一些非石灰岩栖息地的食草哺乳动物支持资源可用性假设，但尚未对生活在石灰岩土壤上生长的植物上的哺乳动物进行评估。包括这种恶劣的栖息地是必要的，以联系土壤条件在各种各样的环境和各种各样的食草哺乳动物的行为生态学。该石灰岩栖息地的摄食数据将与现有的灵长类动物饮食和运动适应性进行比较，这些灵长类动物来自具有广泛土壤、植物和基质分布的栖息地。该项目将通过与越南国立大学（VNU）、河内理工大学（HUS）和河内生态与生物资源研究所（IEBR）的学生和同事的国际合作，扩大代表性不足的群体对科学的参与。当地村民将在该项目中得到雇佣和培训。其次，除了提高对德拉库尔叶猴及其石灰岩栖息地的科学知识外，该项目还将通过确定栖息地需求、栖息地使用和种群的长期生存能力来改善对这种极度濒危物种的保护。整个已知的德拉库尔叶猴种群都在越南北部地区。最后，对该项目的支持将进一步培养一名体质人类学女研究生。

Trachypithecus delacouri inhabit an unusually harsh environment in Vietnam where they move and feed on rough, sparsely vegetated karst (limestone) formations. These remarkable, critically endangered primates are virtually unstudied and little is known about feeding ecology in karst forests. This study will provide data on the dynamics between soil quality, plant chemistry, and food selection, that is, how do plant-eating mammals balance their nutritional requirements with the poisonous compounds present in the plant foods they eat. The soil influences the chemical nature of its plants. Herbivores make feeding and locomotor decisions based on such plant constituents as well as on the efficacy of accessing food. The fact that a leaf-eating monkey in a food-limited habitat is restricted both by challenging substrates and harsh soil conditions that produce stunted vegetation has important implications for adaptation. While there is an abundance of evidence suggesting how plant-eating primates make feeding decisions in other types of environments, there is no evidence as to what factors influence feeding decisions in a karst habitat. Determining the role of soil type, plant defensive compounds, and substrate availability on the foraging of Delacour's langurs in a geographically and food-limited environment has far-reaching implications for the locomotor and dietary adaptations of all primates. Further, this project will shed light on how these monkeys, and thus plant-eaters in general, adapt to karst's presumed low resource environment. Soil, leaf, and behavioral analyses will be used to analyze the food selection of two groups of free-ranging Delacour's langurs on an isolated karst mountain in northern Vietnam. These data will be used to evaluate the resource availability hypothesis, the idea that plants invest heavily in defenses in environments where resources for plant growth are limited. Support for the resource availability hypothesis comes from several herbivorous mammals in non-limestone habitats, but has not been evaluated in mammals that live on plants that grow on limestone soils. The inclusion of this harsh habitat is necessary to relate soil conditions in a wide variety of environments to the behavioral ecology of a diverse array of plant-eating mammals. Feeding data from this limestone habitat will be compared with the available primate dietary and locomotor adaptations from habitats with a wide range of soil, vegetative, and substrate distributions.This project will broaden the participation of underrepresented groups in science through an international collaboration with students and colleagues from Vietnam National University (VNU), Hanoi University of Science (HUS), and the Institute of Ecology and Biological Resources (IEBR) in Hanoi. Local villagers will be employed and trained in this project. Second, in addition to enhancing scientific knowledge about Delacour's langurs and their limestone habitat, this project will improve protection of this critically endangered species by determining habitat requirements, habitat usage, and long-term viability of the population. The entire known population of Delacour's langurs is found in this northern Vietnam region. Finally, support for this project will further the training of a female graduate student in physical anthropology.