Finding and establishing new subpopulations

当一个动物亚群灭绝时，剩下的个体分散寻找新的栖息地，开始新的亚群。我计划研究这一过程的三个步骤--搜索、发现栖息地和在这些栖息地建立亚种群。因此，我建议找出哪些类型的运动模式在寻找栖息地斑块方面最成功，这种成功如何取决于栖息地斑块的分布，小型哺乳动物在未知栖息地旅行时实际使用哪些运动模式，以及使用的运动模式类型如何取决于栖息地类型。我还将测量在实验操作的栖息地中，小型哺乳动物的感知范围(从它们可以检测到栖息地斑块的距离)随着栖息地和离家范围的距离而变化的程度。据悉，现场实验将使用小型哺乳动物(田鼠和老鼠)进行。这些动物价格便宜，易于操作，使我们能够非常迅速地获得大样本。这些动物将使用无线电遥测和线程假脱机相结合的方式进行跟踪。将使用一种新开发的统计技术来分析移动路径，该技术区分随机移动和定向移动。他们说，一旦动物找到了新的栖息地，它们就需要建立一个新的亚种群。我的研究的第三部分将着眼于在可变环境中建立新的亚种群。当子总体较小时，随机事件对成功几率有很大影响。此外，我还建议找出种群规模如何影响存活率，以及条件的可变性如何影响存活率。他们表示，这项工作将使用海狸进行。随机事件是冲刷水坝的风暴。当大坝很小的时候，它们很容易被暴风雨冲毁。我建议对大面积的水坝进行调查，然后根据水坝的大小和风暴的大小，比较不同季节水坝的成功与否。

When a subpopulation of animals goes extinct, then residual individuals disperse in search of new habitat patches to start new subpopulations. I plan to study three steps of this process - searching, discovering habitat patches, and establishing subpopulations in those habitat patches.     I propose to find out which types of movement patterns are most successful for finding habitat patches, how this success depends on the distribution of habitat patches, which movement patterns do small mammals actually use when travelling in unknown habitats, and how the type of movement pattern used depends on habitat type. I will also measure how perceptual range (from how far away they can detect the habitat patches) varies with habitat and distance from home range for small mammals in experimentally manipulated habitats.     The field experiments will be carried out using small mammals (voles and mice). These animals are cheap and easy to work with, allowing us to get large sample sizes quite quickly. The animals would be tracked using a combination of radio-telemetry and thread-spooling. Movement paths would be analysed using a newly-developed statistical technique that differentiates between random and directed movement.     Once animals find a new habitat patch, they need to establish a new subpopulation. The third part of my research will look at the establishment of new subpopulations in variable environments. When subpopulations are small, random events have a large impact on the chance of success.     I also propose to find out how population size affects survival probability, and how variability in conditions affects survival rate.     This work would be carried out using beavers. The random events are storms that wash out dams. When dams are small, they are easily washed out by storms. I propose to survey dams over a large area, and then compare the success of the dams from one season to the next, as a function of dam size and size of storms.