USDA Forest Service Rocky Mountain Research Station, 800 East Beckwith, Missoula, Montana 59801, USA.
Ecology. 2009 Nov;90(11):3222-32. doi: 10.1890/08-1287.1.
Wolverines (Gulo gulo) are one of the rarest carnivores in the contiguous United States. Effective population sizes in Montana, Idaho, and Wyoming, where most of the wolverines in the contiguous United States exist, were calculated to be 35 (credible limits, 28 52) suggesting low abundance. Landscape features that influence wolverine population substructure and gene flow are largely unknown. Recent work has identified strong associations between areas with persistent spring snow and wolverine presence and range. We tested whether a dispersal model in which wolverines prefer to disperse through areas characterized by persistent spring snow cover produced least-cost paths among all individuals that correlated with genetic distance among individuals. Models simulating large preferences for dispersing within areas characterized by persistent spring snow explained the data better than a model based on Euclidean distance. Partial Mantel tests separating Euclidean distance from spring snow-cover-based effects indicated that Euclidean distance was not significant in describing patterns of genetic distance. Because these models indicated that successful dispersal paths followed areas characterized by spring snow cover, we used these understandings to derive empirically based least-cost corridor maps in the U.S. Rocky Mountains. These corridor maps largely explain previously published population subdivision patterns based on mitochondrial DNA and indicate that natural colonization of the southern Rocky Mountains by wolverines will be difficult but not impossible.
狼獾（Gulo gulo）是美国本土最稀有的食肉动物之一。在蒙大拿州、爱达荷州和怀俄明州（美国本土大部分狼獾的栖息地），对有效种群数量进行了计算，结果表明数量较少，约为 35（可信区间：28-52）。影响狼獾种群亚结构和基因流动的景观特征在很大程度上是未知的。最近的研究已经确定了与持久春季积雪区和狼獾栖息地和范围之间存在强烈关联的区域。我们测试了一种扩散模型，即狼獾更喜欢通过持久春季积雪覆盖的区域进行扩散，该模型在所有个体之间产生了与个体间遗传距离相关的最低成本路径。模拟对持久春季积雪覆盖区域内扩散的强烈偏好的模型比基于欧几里得距离的模型更好地解释了数据。部分 Mantel 检验将欧几里得距离与基于春季积雪覆盖的效应分离，表明在描述遗传距离模式时，欧几里得距离并不重要。由于这些模型表明成功的扩散路径遵循春季积雪覆盖的区域，我们利用这些认识在美国落基山脉得出了基于经验的最低成本走廊图。这些走廊图在很大程度上解释了先前基于线粒体 DNA 发表的种群划分模式，并表明狼獾对落基山脉南部的自然殖民化将是困难的，但并非不可能。
