EAGER: Climatic influences on migratory fidelity

动物如何应对气候变化是生态学中一个核心和有争议的问题。这个项目将研究阿拉斯加北方驯鹿脱落的鹿角如何揭示随着几十年和几个世纪的气候变化，雌性驯鹿在多大程度上改变了它们分娩的地点（它们的“产犊地”）。这是可能的简单事实，即女性每年生长鹿角，并在分娩后的几天内脱落，脱落的鹿角不会分解。 持续了几个世纪，它们可以被发现，收集和分析，以揭示它们是何时脱落的。研究人员将把这些信息与每只雌性动物分娩时的单独气候记录联系起来。鹿角也可以揭示迁徙的模式。关键是，这种简单的方法允许人们在与自然气候周期相匹配的时间尺度上测量气候的影响。具有许多假设的复杂模型是不必要的。这项工作通过提供数据来帮助管理驯鹿种群而使社会受益。研究人员将促进美国和加拿大的科学家，管理人员和政策制定者之间的沟通。最后，该项目将支持北极避难所附近Gwich'in土著民族一个村庄的学龄学生以及辛辛那提的小学、大学和研究生的外联和培训活动，俄亥俄州。这个项目使用棚雌性驯鹿鹿角从沿海平原产犊场豪猪驯鹿群采样（北极避难所），以确定产犊地的地理分布如何随着时间的推移而变化。核心假设是，与生殖有关的景观利用的变化（即，产犊场）受气候影响很大。对于每只鹿角，将使用放射性碳测年和骨腐烂的时间校准状态的组合来估计脱落日期。在十年到百年的时间尺度上，产犊地的地理分布变化将与北极涛动的记录相结合，以测试气候对迁移保真度的作用，并评估当前气候轨迹对未来长距离（驯鹿）迁移的影响。本研究的目的是（1）建立一个全鹿角模型，以确定未知的驯鹿鹿角的性别，（2）建立北极骨风化的阶段和速率，（3）量化气候对驯鹿产犊场地理变异的影响。 更广泛地说，这项工作将突出骨积累作为人口生物学的十年至百年尺度数据的来源-一种有潜力大大扩展人口和社区生态学许多方面研究的时间尺度的资源。该奖项反映了NSF的法定使命，并被认为值得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来支持。

How animals may respond to climate change is a central and controversial issue in ecology. This project will examine how antlers shed by caribou in northern Alaska can reveal how much females have changed the location of where they give birth (their “calving grounds”) as climate has shifted over decades and centuries. This is made possible by the simple facts that females grow antlers every year and shed them within days of giving birth and that the shed antlers do not break down. Lasting for centuries, they can be found, collected and analyzed to reveal when they were shed. The researcher will link that information with separate records of climate at the time each female gave birth. The antlers can also reveal patterns of migration. The key point is that this simple approach allows one to measure the influence of climate across time scales that match those of natural climate cycles. Complicated models with many assumptions are unnecessary. This work benefits society by providing data to help manage caribou populations. The researcher will foster communication between scientists, managers, and policy makers in the USA and Canada. Finally, the project will support outreach and training activities for school-aged students in a village of the Gwich'in Indigenous Nation near the Arctic Refuge, as well as primary school, college, and graduate students in Cincinnati, Ohio.This project uses shed female caribou antlers sampled from the Coastal Plain calving grounds of the Porcupine Caribou Herd (Arctic Refuge) to identify how the geographic distribution of calving grounds has changed through time. The central hypothesis is that variability in reproductively-tied landscape use (i.e., calving grounds) is strongly influenced by climate. For each antler, date-of-shed will be estimated using a combination of radiocarbon dating and time-calibrated states of bone decay. Changes in the geographic distribution of calving grounds across decadal- to centennial-timescales will be paired with records of the Arctic Oscillation to test the roles of climate on migratory fidelity and to evaluate impacts of current climate trajectories on future long-distance (caribou) migration. The aims of this research are to (1) establish a whole-antler model for determining sex of unknown caribou antlers, (2) establish the stages and rates of arctic bone weathering, and (3) quantify the climatic influences on the geographic variability of caribou calving grounds. More broadly, this work will highlight bone accumulations as sources of decadal- to centennial-scale data on population biology -- a resource with potential to dramatically expand the timescales with which many aspects of population and community ecology are studied.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.