Geomagnetic Imprinting and Natal Homing in Sea Turtles

动物在长途迁徙中准确无误地引导自己的能力让人类既敬畏又羡慕，直到最近，人类才通过全球定位技术，成功地赶上了红海龟等精英动物导航员的技能。这些海龟在孵化时离开家乡的海滩，在整个海洋盆地迁徙，几年后才回到它们起源的同一沿海地区筑巢。成年海龟如何导航到它们出生的海滩仍然是个谜，但越来越多的证据表明，海龟在它们出生的海滩上留下了独特的地磁特征，然后利用这些信息返回。本研究将采用多学科方法研究地磁印记假说。研究结果将有助于保护海龟等经历出生归巢的动物。例如，将海龟重新引入它们曾经筑巢的地理区域的尝试基本上是不成功的，因为在这些区域释放的小海龟很少成年后返回。提高对海龟如何找到家园海滩的了解可能有助于拯救这些濒临灭绝的物种。研究结果还可能揭示新的导航模式，适用于人类和自动驾驶汽车的导航系统。更广泛的影响包括为本科生和研究生提供研究经验，通过北卡罗来纳自然历史博物馆向K12教室传播研究结果，并为K12教育创建教学网络模块，从而加强科学教育和公众对濒危海龟的认识。这项研究的长期目标是确定海龟和其他长途海洋迁徙者出生时归巢的行为和感觉机制。该研究将验证地磁印记假说的几个核心预测：(1)行为实验将调查筑巢的成年雌海龟是否利用其出生区域的独特磁特征来定位它们的出生海滩；(2)利用统计分析确定大陆海岸线上的海龟巢的空间分布是否像地磁印记假说所预测的那样受到地球磁场波动的影响；(3)研究海龟胚胎在孵化前的磁性取向行为，以确定在发育过程中是否会发生印记。结果和数据将主要在科学期刊上传播；在可能的情况下，适当的数据和元数据文件将以在线补充材料的形式发布，或通过许多期刊现在支持的Dryad等服务发布。

The ability of animals to guide themselves unerringly during long-distance migrations has inspired both awe and envy in humans, who only recently, through global positioning technology, managed to equal the skills of elite animal navigators such as loggerhead sea turtles. These turtles leave their home beaches as hatchlings and migrate across entire ocean basins before returning years later to nest in the same coastal area where they originated. How adult turtles navigate to their natal beaches has remained enigmatic, but accumulating evidence suggests that turtles imprint on the unique geomagnetic signature of their natal beach and then use this information to return. The research will investigate the geomagnetic imprinting hypothesis using a multidisciplinary approach. Results will assist efforts to conserve animals such as sea turtles that undergo natal homing. For example, attempts to reintroduce sea turtles to geographic areas where they once nested have been largely unsuccessful because young turtles released in such areas seldom return as adults. An improved understanding of how turtles find their home beaches may help save these jeopardized species from extinction. Findings are also likely to reveal new modes of navigation that can be adapted for guidance systems of humans and autonomous vehicles. Broader impacts include providing research experience for undergraduate and graduate students, broadcasting findings into K12 classrooms through the North Carolina Museum of Natural History, and creating instructional web modules for K12 education, thereby enhancing both science education and public awareness of endangered sea turtles.The long-term objective of the research is to determine the behavioral and sensory mechanisms that underlie natal homing in sea turtles and other long-distance marine migrants. The research will test several central predictions of the geomagnetic imprinting hypothesis: (1) behavioral experiments will investigate whether nesting adult female turtles locate their natal beaches using the unique magnetic signature of their natal area; (2) statistical analyses will be used to determine whether the spatial distribution of turtle nests along continental coastlines is affected by fluctuations in Earth's magnetic field, as the geomagnetic imprinting hypothesis predicts; and (3) magnetic orientation behavior of turtle embryos prior to hatching will be studied to determine if imprinting might occur during development. Results and data will be disseminated primarily in scientific journals; when possible, appropriate data and metadata files will be posted in online supplementary materials or with services such as Dryad, which many journals now support.