Spatio-Temporal Mosaics in Cycling Populations: The Role of Species Interactions

有相当大的兴趣，在人口动态的时空变化，包括人口规模的变化，周期性的倾向，以及一些自由放养的昆虫，鸟类和哺乳动物的地理分布明显增加。气候变化和其他大规模的压力因素被归咎于这种现象，但迄今为止，物种相互作用的作用机制框架尚未得到仔细审查。该研究计划将解决与物种相互作用在循环衰减和地理范围损失中的作用有关的悬而未决的问题。首先，在南部人口的加拿大猞猁，我们将评估的作用，通过监测空间位移通过GPS遥测的捕食者公会（猞猁，郊狼，山猫）的猞猁行为的竞争（即冲突）。剥削性竞争（即，食物）假说将通过对三种食肉动物在其分布范围内进行稳定同位素分析，并根据猎物的可获得性和食肉动物的同域水平来检查饮食重叠的程度。 其次，雪鞋野兔感知捕食风险的反应将通过实地实验改变这种风险的核心和外围的分布和记录行为，生理和人口的反应。 捕食对野兔种群周期的直接和间接作用，包括通过与气候的相互作用，将通过种群模型进行评估。 第三，我们将比较当代的人口分析方法，以确定哪种方法对检测生态数据集中的周期性和周期性衰减最敏感，然后使用全球人口动态数据库检查这些动态特性的普遍性。 第四，我们将明确测试的竞争和捕食风险的循环动力学的作用进行实验，使用轮虫-捕食者（捕食者-猎物）系统，使我们能够推断种群水平的反应。因此，总的来说，这个计划将提供全面的洞察物种相互作用对人口变化模式的作用，从而帮助我们更好地理解为什么许多自然种群似乎正在经历动态变化。

There is considerable interest in the apparent increase in spatio-temporal variability in population dynamics, including changes in population size, cyclic propensity, and geographic distribution of a number of free-ranging insects, birds, and mammals. Climate change and other broad-scale stressors have been blamed for such phenomena, but to date a mechanistic framework for the role of species interactions has not been given careful scrutiny. The research program will resolve outstanding questions related to the role of species interactions in cyclic attenuation and geographic range loss. First, in a southern population of Canada lynx, we will evaluate the role of agonistic competition (i.e. strife) on lynx behaviour via monitoring spatial displacement via GPS telemetry of the predator guild (lynx, coyote, bobcat). The exploitative competition (i.e., food) hypothesis will be examined by conducting stable isotope analysis for the 3 carnivores across their range, and examining the extent of dietary overlap according to prey availability and carnivore levels of sympatry. Second, snowshoe hare responses to perceived predation risk will be examined via a field experiment altering such risk in the core and periphery of their distribution and documenting behavioural, physiological, and demographic responses. The direct and indirect role of predation on hare population cycles, including through interaction with climate, will be assessed via population models. Third, we will compare contemporary methods of population analysis to determine which is most sensitive to detecting cyclicity and cyclic attenuation in ecological datasets, and then examine the prevalence of these dynamical properties using the Global Population Dynamics Database. Fourth, we will explicitly test the role of competition and predation risk on cyclic dynamics by conducting experiments using a rotifer-alga (predator-prey) system that allows us to infer population-level responses. Thus, collectively this program will provide comprehensive insight into the role of species interactions on patterns of population change, and thereby help us better understand why many natural populations seem to be undergoing dynamical variability.