Interpreting Pleistocene Predator-Prey Dynamics: inference from dental growth and attrition

这项奖励的资金将用于开发可应用于哺乳动物化石种群的新的哺乳动物健康牙齿和骨骼指标。要做到这一点，将使用过去50年来从一对经过充分研究的捕食者-猎物对--皇家岛国家公园灰狼和驼鹿--收集的颌骨来记录整体健康和动物解剖之间的关系，众所周知，这些猎物遭受了多次食物短缺。将根据捕食者和猎物牙齿和骨骼的可量化的微观和宏观特征来评估捕食者和猎物的营养压力。在化石中发现这些指示物的能力将在加利福尼亚州兰乔拉布莱亚焦油渗漏沉积物中灭绝的野牛身上进行测试，这些沉积物的年龄在5万到11000年之间。假设这种方法有效，它可以用来推断过去群落中捕食者和猎物的相对种群规模，比如大约12000年前人类到达时的北美。如果这些被捕食的动物几乎没有表现出食物压力的证据，那么它们的种群密度很低，可能是因为大型食肉动物的强烈捕食。在这种情况下，与高密度相比，人类猎人的到来更有可能导致猎物物种的灭绝。因此，该项目可以阐明人类在晚更新世大型哺乳动物灭绝中可能扮演的角色。

Funds from this award will be used to develop new tooth and skeletal indicators of mammal health that can be applied to fossil populations of mammals. To do so, the association between overall health and the animal's anatomy will be documented using jaws collected over the past fifty years from a well-studied predator-prey pair, Isle Royale National Park gray wolf and moose, that are known to have suffered multiple food shortages. Nutritional stress in predator and prey will be assessed based on quantifiable microscopic and macroscopic features of their teeth and skeletons. The ability to see these indicators in fossils will then be tested on extinct bison from the Rancho La Brea tar seep deposits of California that are between 50,000 to 11,000 years old. Assuming the method works, it can be used to infer relative population sizes of predator and prey in past communities, such as North America at the time of human arrival about 12,000 years ago. If these prey animals show little evidence of food stress, then their population densities were low, probably due to intense predation by large predator carnivores. Under these conditions, the arrival of human hunters would have been more likely to lead to the extinction of prey species than if they were at high densities. Thus, this project can illuminate the possible role of humans in the late Pleistocene large mammal extinctions.