Lynx cycles and barriers: Evaluating dispersal versus climate change in flatlining populations

由专门的捕食者及其猎物产生的持续和有规律的种群周期在自然界中是罕见的，但似乎是在北方生态系统中创造周期性节奏的主要力量。加拿大猞猁（lynx canadensis）和雪靴兔（Lepus americanus）表现出这种普遍的10年周期。这些动态系统的健康正处于危险之中，美国猞猁的濒危状态和加拿大南部猞猁数量的减少就是证据。例如，近年来，加拿大南部喀斯喀特山脉和华盛顿州北部的猞猁数量减少了大约一半。猞猁在美加边境附近的持续存在可能取决于与加拿大核心人口的分散联系的质量，或者在气候变化永久改变物种动态之前阻止气候变化的进展。我们建议评估替代假设来解释猞猁-野兔周期的周期性和振幅的崩溃：捕食者扩散的均质化效应与环境季节性的减少（假设维持10年周期）。我的研究成果是：1)评估气候变化或扩散障碍是否是南方猞猁循环崩溃背后的主要生物机制；2)使用一个辐射项圈猞猁样本创建一个促进扩散的栖息地模型，并制作栖息地/扩散地图，识别通过该物种范围南部主要猞猁栖息地的移动障碍。了解扩散趋势对于管理栖息地破碎化和保护栖息地连接至关重要。另一种可能是，气候变化可能正在迅速破坏北方森林的人口循环。这项研究将有利于野生动物管理者、林业和其他资源开采行业、诱捕行业和种群生态学的集体知识。

Persistent and regular population cycles produced by specialist predators and their prey are a rarity in nature, but appear to be a major force creating a periodic rhythm in boreal ecosystems. Canadian lynx (Lynx canadensis) and snowshoe hare (Lepus americanus) display such a pervasive 10-year cycle. The health of these dynamic systems are at risk as evidenced by the threatened status of the lynx in the US and low numbers in what remains of its southern range in Canada. For instance, lynx numbers in the Cascades Mountain Range of southern Canada and northern Washington have approximately halved in recent years. The persistence of lynx near the Canada-US border may depend on either quality of dispersal connections with the core Canadian population or stemming the progression of climate change before it permanently alters the species' dynamics.We propose to evaluate alternative hypotheses to explain the breakdown in the periodicity and amplitude of the lynx-hare cycle: the homogenizing effect of predator dispersal versus the reduction in environmental seasonality that is hypothesized to maintain the 10-year cycle. My research outcomes are to 1) evaluate if either climate change or barriers to dispersal is the main biological mechanism behind the breakdown of southern lynx cycles and 2) use a sample of radiocollared lynx to create a model of habitats that facilitate dispersal and produce habitat/dispersal maps identifying barriers to movement through key lynx habitats in the southern portions of the species' range.  Understanding dispersal trends is essential for managing habitat fragmentation and protecting habitat connections.   Alternatively, climate change might be rapidly dismantling population cycles in the boreal forest.  This study will benefit wildlife managers, forestry and other resource extraction industries, the trapping industry, and the collective knowledge of population ecology.