Of Moths and Mice: The Influence of Dispersal Distance and Local Predation Risk on Persistence of a Sparse Prey

飞蛾和老鼠：扩散距离和局部捕食风险对稀疏猎物持久性的影响克莱夫·G·琼斯、布雷特·J·古德温、理查德·S·奥斯菲尔德和埃里克·M·肖伯。捕食者可能会灭绝猎物的种群。了解猎物种群如何在捕食面前坚持下去，可以帮助我们维持濒危物种的种群，并控制害虫种群。例如，吉普赛飞蛾是引进的害虫，在北美东部的阔叶林中造成很大破坏。白脚老鼠在这些森林中大量存在，是吉普赛蛾蛹上的贪婪捕食者，能够将当地的蛾子赶尽杀绝。既然飞蛾实际上并没有在更大的区域内灭绝，面对老鼠的猛烈捕食，飞蛾是如何坚持下来的？两个因素的综合影响是重要的：(1)吉普赛蛾幼虫受到攻击的可能性因地而异；(2)吉普赛蛾毛虫在其有生之年不会分散很远。计算机模拟表明，将这两个因素结合起来，可以大大增加蛾类种群持续存在的可能性。在该项目期间，将在纽约州的橡树林中收集数据，以便开发、改进和测试这些模拟模型。将测量吉普赛蛾毛虫在几个地点的扩散距离和对吉普赛蛾蛹的捕食风险。这些测量结果将被纳入计算机模拟，以预测捕食风险空间模式的改变将如何影响吉普赛飞蛾的数量。最后，通过设置喂食站来操纵老鼠觅食的模式，将在有不同数量分散的蛾毛虫的地区检验预测。这一过程将改变对吉普赛蛾蛹的捕食风险，并应以可预测的方式改变当地蛾种群持续存在的可能性。

Of Moths and Mice: The Influence of Dispersal Distance and LocalPredation Risk on Persistence of a Sparse PreyClive G. Jones, Brett J. Goodwin, Richard S. Ostfeld and Eric M. Schauber.Predators can potentially exterminate populations of their prey. Understanding how prey populations persist in the face of predation can help us sustain populations of endangered species and control pest populations. For example, gypsy moths are introduced insect pests that cause much damage in hardwood forests of eastern North America. White-footed mice, which are abundant in these forests, are voracious predators on gypsy moth pupae and are capable of driving moths locally to extinction. Since moth extinction has not actually happened over larger areas, how do moths persist in the face of intense predation by mice? The combined effects of two factors are important: (1) the likelihood of a gypsy moth pupa being attacked varies from place to place and (2) gypsy moth caterpillars do not disperse very far during their lifetimes. Computer simulations indicate that combining these two factors can substantially increase the chances that moth populations will persist. During this project, data will be collected in oak forests in New York State that will allow the development, refinement and testing of these simulation models. The dispersal distances of gypsy moth caterpillars and the predation risk for gypsy moth pupae at several sites will be measured. These measurements will be incorporated into the computer simulation to predict how changing the spatial pattern of predation risk would affect gypsy moth populations. Finally, predictions will be tested in areas where there are different numbers of dispersing moth caterpillars by putting out feeding stations to manipulate the patterns of mouse foraging. This procedure will alter the risk of predation for gypsy moth pupae and should change the likelihood of local moth population persistence in a predictable way.