LTREB: Evaluating population cycles and spatial synchrony using long-term demographic and genetic data on snowshoe hares

雪鞋兔提供了种群规模周期性、同步波动的经典教科书例子。加拿大和阿拉斯加的野兔周期以其8-11年的规律性和高峰和低密度之间20到50倍的振幅差异而闻名。同样值得注意的是，在这一范围的大部分地区，人口波动是同步的。循环动力学和空间同步性似乎在野兔活动范围的南部地区被打破，在那里，雪鞋兔的栖息地更加分散，种群间的迁徙更加困难。造成人口同步和同步中断的因素仍然是推测性的。通过在连续的美国扩展一个独特的、空间上广泛的野兔动态时间序列，PI Mills建议测试长期持有的假设，这些假设说明了野兔动态的纬度梯度和人口连通性在产生这些地理模式中的作用。9年的初步数据表明，南方种群表现出比以前认识到的更大的时间波动，而且这些种群在遗传上比跨越类似空间范围的北方种群更加独特。了解野兔动态的模式和原因将促进对影响大规模人口过程的因素的基本了解，并对保护和管理许多生态系统产生影响。种群周期和同步动态，虽然以雪鞋兔为例，但也存在于许多分类群中，包括各种昆虫、鱼类、橡树、病毒、松鸡和大型哺乳动物，包括驯鹿和麝牛。尤其值得关注的是种群的同步性和连通性可能会直接影响一个物种的长期持久性。这项研究的另一个应用是保护，因为加拿大猞猁几乎完全以雪鞋野兔为食，在阿拉斯加以外的美国联邦受到威胁。PI已经建立了一个正式的本科生指导计划，并计划让许多研究生和本科生参与这个实地项目。最后，收集到的所有数据将在收集后的1.5年内向公众开放。

Snowshoe hares provide the classical textbook example of cyclical, synchronous fluctuations in population size. Hare cycles in Canada and Alaska are legendary for their 8-11 year regularity and their 20- to 50-fold amplitude difference between peak and low population densities. Equally as remarkable, population fluctuations are synchronized across much of this range. Cyclic dynamics and spatial synchrony appear to break down in the southern parts of the hare's range, where habitats for snowshoe hares are more fragmented and movements among populations more difficult. The factors responsible for population synchrony and for the breakdown of synchrony, remain speculative. By extending a unique, spatially extensive time series of hare dynamics in the continguous US, PI Mills proposes to test long-held hypotheses accounting for a latitudinal gradient in hare dynamics and the role of population connectivity in generating these geographic patterns. Nine years of preliminary data suggest that southern populations exhibit greater temporal fluctuations than previously recognized, and that these populations are more distinct genetically than are northern populations spanning a similar spatial extent. Understanding patterns and causes of hare dynamics will advance the basic understanding of factors that influence large-scale population processes, with implications for conserving and managing many ecological systems. Population cycles and synchronous dynamics, though famously exemplified by snowshoe hares, occur in many taxa, including various insects, fish, oaks, viruses, grouse, and large mammals including caribou and muskox. Of particular conservation concern is the possibility that population synchrony and connectivity may directly affect the long-term persistence of a species. An additional application of this research to conservation arises because Canada lynx, which feed almost exclusively on snowshoe hares, are federally threatened in the U.S. outside of Alaska. The PI has established a formal program for undergraduate mentoring, and plans to involve a host of graduate and undergraduate students in this field project. Finally, all data collected will be available to the general public within 1.5 years of their collection.