Demographic responses of a site-faithful and territorial predator to its fluctuating prey: long-tailed skuas and arctic lemmings

1. Environmental variability, through interannual variation in food availability or climatic variables, is usually detrimental to population growth. It can even select for constancy in key life-history traits, though some exceptions are known. Changes in the level of environmental variability are therefore important to predict population growth or life-history evolution. Recently, several cyclic vole and lemming populations have shown large dynamical changes, that might affect rodent predator demography or life histories. 2. Skuas constitute an important case study among rodent predators, because of their strongly saturating breeding productivity (they lay only two eggs) and high degree of site fidelity, in which they differ from nomadic predators raising large broods in good rodent years. This suggests that they cannot capitalize on lemming peaks to the same extent as nomadic predators, and might be more vulnerable to collapses of rodent cycles. 3. We develop a model for the populat...

1. 环境变异性（Environmental variability）通常通过食物可获得性或气候变量的年际变化对种群增长产生不利影响，甚至可对关键生活史性状施加稳定性选择，尽管目前已有部分例外案例被报道。因此，环境变异性水平的变化对于预测种群增长或生活史演化至关重要。近期多项研究发现，部分周期性田鼠与旅鼠种群出现了显著动态变化，这可能会影响啮齿类捕食者的种群统计学特征或生活史。
2. 贼鸥（Skuas）是啮齿类捕食者研究中的重要案例类群：它们的繁殖生产力具有强烈的饱和特性（仅产卵2枚），且具备极高的恋巢保真度，这与在啮齿类种群丰盛年份可抚育大量幼雏的游牧型捕食者截然不同。研究表明，贼鸥无法像游牧型捕食者那样充分利用旅鼠种群爆发高峰，因此可能更易受到啮齿类周期崩溃的冲击。
3. 我们构建了针对种群……的模型