Predator persistence in fragmented forests: lynx and snowshoe hares

濒危物种面临的主要威胁之一是栖息地的丧失。 在森林中，这种损失往往使原始森林的残余林分被年龄或物种组成不同的其他林分所包围。 对于森林哺乳动物，这些复杂的镶嵌不同的立场类型强烈影响人口动态;对于一些物种，人口下降，栖息地破碎化的发生。 通常，森林中的捕食者和猎物会对不同空间尺度的破碎化作出反应，猎物停留在特定的林分中，而捕食者则在林分之间移动。 随着栖息地的丧失，猎物可以使用的林分变得更小或更远，捕食者可能无法获得足够的猎物来生存，因为带着猎物在林分之间旅行的成本变得太高。 我感兴趣的是森林哺乳动物如何应对森林破碎化，我的主要研究目标是解释如何捕食者-猎物的相互作用是改变景观变得越来越分散。 猎物在不同林分类型的种群动态将在很大程度上决定他们的捕食者是否可以坚持在一个支离破碎的景观。 在一个极端，猎物可能只使用少数几个，相距很远的立场;在另一个极端，他们可能会出现在大多数立场。 作为一个模型系统，我专注于雪鞋野兔（美洲兔）和加拿大猞猁（猞猁加拿大）在蒙大拿州西部。 我正在描述不同林分类型中野兔的密度、存活率和繁殖率。 然后，我正在探索猞猁用于狩猎的立场类型，它们在杀戮之间的旅行距离，以及它们在该地区的饮食中野兔的比例。 我正在将这些结果统一到空间模型中，这样我就可以模拟改变不同类型栖息地对这些物种的影响。 这项研究计划将推进我们对捕食者和猎物如何应对森林碎片化的一般理解，以及预测剩余森林的配置，这可能有助于保留景观中的物种。

One of the major threats to imperiled species is the loss of habitat. In forests, this loss often leaves remnant stands of the original forest surrounded by other stands that differ in age or species composition. For forest mammals, these complex mosaics of different stand types strongly affect population dynamics; for some species, populations decline as habitat fragmentation occurs. Often, predators and prey in forests will respond to fragmentation at different spatial scales, with prey staying in particular forest stands and predators moving among stands. As habitat loss occurs and the stands that prey can use become smaller or farther apart, predators may not be able to obtain enough prey to survive because the cost of traveling among the stands with prey becomes too high. I am interested in how forest mammals respond to forest fragmentation, and my main research objective is to explain how predator-prey interactions are changed as a landscape becomes increasingly fragmented. The population dynamics of prey in different stand types will largely determine whether their predators can persist in a fragmented landscape. At one extreme, prey might use only a few, far apart stands; at the other extreme, they might occur in the majority of stands. As a model system, I am focusing on snowshoe hares (Lepus americanus) and Canada lynx (Lynx canadensis) in western Montana. I am characterizing density, survival, and reproduction of hares in different stand types. I am then exploring which stand types lynx use for hunting, how far they travel between kills, and what proportion of their diet consists of hares in this region. I am unifying these results in spatial models so that I can model the effects of changing the amount of different types of habitat on these species. This research program will advance our general understanding of how predators and prey respond to forest fragmentation, as well as predicting configurations of remaining forest stands that might help to retain species in the landscape.