SGER: Does Manipulation of Top Predators Lead to Rapid Shifts in the Structure of Ecological Communities?

这个SGER项目将利用即将重新引入狐狸到圣米格尔岛的机会，圣米格尔岛是加利福尼亚州南部海岸外海峡群岛的一部分。1998年，岛狐(Urocyon Littoraris)被从圣米格尔岛移走。在狐狸被移走后，当地的啮齿动物数量(由一种Permyscus物种组成)出现了戏剧性的增长，达到每公顷超过900只老鼠的密度--是附近圣克鲁斯岛上狐狸出没的密度的30倍。有一些证据表明，圣米格尔上狐狸的移居和捕食啮齿动物的急剧增加导致了植物群落的迅速变化。这种SGER将允许对圣米格尔上的小型哺乳动物猎物群落进行实时跟踪，以回应重新引入的狐狸，并以狐狸对植物群落的短期和长期影响为中心。对比将包括在狐狸重新引入之前和之后的圣米格尔，与圣尼古拉斯岛，那里的狐狸已经存在至少2000年，以及圣巴巴拉岛，那里从未出现过狐狸(至少最近)。该方法将使用封闭来控制捕食者和啮齿动物的进入，以便量化具有不同捕食者历史和不同当代捕食者活动的岛屿上自上而下对植物群落的影响(即在圣米格尔重新引入)。该项目的应用范围可能相当大，特别是考虑到群岛上有数百种稀有和濒危植物。因为公园管理局负责监督海峡群岛，所以有机会与公园志愿者进行接触，并通过一些相当不寻常的渠道了解任何结果。这项研究将支持一名女研究生。

This SGER project would capitalize upon the imminent reintroduction of foxes to San Miguel Island, part of the Channel Islands off the coast of southern California. The Island Fox (Urocyon littoralis) was removed from San Miguel Island in 1998. Following fox removal, the native rodent population (consisting of a single Peromyscus species) has shown dramatic increases, attaining densities of over 900 mice per hectare - thirty times greater than densities on nearby Santa Cruz Island where fox are present. There is some evidence that the removal of foxes on San Miguel and the dramatic increase in their rodent prey led to rapid changes in the plant community. This SGER would allow the real-time tracking of the small mammal prey community on San Miguel in response to reintroduced foxes, with the immediate and longer term effects that foxes have on the plant community a central focus. Contrasts will include San Miguel before and after fox reintroduction, with San Nicolas Island where foxes have been present for at least 2000 years, and Santa Barbara Island where foxes have never been present (at least recently). The approach would be to use exclosures to manipulate predator and rodent access in order to quantify top-down influences on plant communities across islands with different predator histories as well as different contemporary predator activity (i.e. the reintroduction on San Miguel). The broader applications of the project are potentially quite large, especially considering that the Islands have hundreds of species of rare and endangered plants. Because the Park Service is responsible for oversight of the Channel Islands, there is an opportunity for outreach with Park volunteers, and some fairly unusual outlets for any results. The research would support a female graduate student.