Demography of Verreaux’s sifaka in a stochastic rainfall environment
Demography of Verreaux’s sifaka in a stochastic rainfall environment
复制标题
随机降雨环境中维罗西法卡的人口统计
作者：
R. Lawler;H. Caswell;A. Richard;J. Ratsirarson;R. Dewar;Marion Schwartz
在这项研究中，我们使用确定性和随机模型来分析人口的Verreaux的狐猴（Propithecus verreauxi verreauxi）在波动的降雨环境。该模型基于马达加斯加西南部Beza Mahafaly特别保护区16年的数据。阶段分类的生命周期中的参数估计使用标记-再捕获方法。使用信息理论技术和多模型推理对统计模型进行了评价。最高等级模型是时不变的，但平均模型包括生存和繁殖的总体依赖。我们利用降雨量的时间序列模型来构建一个随机人口模型。时不变模型和随机模型给出的种群增长率约为0.98。增长率的Bootstrap置信区间，包括确定性和随机性，包括1。生长率对成年存活率的变化最有弹性。许多人口统计数据显示出对年降雨量的非线性响应，但当年降雨量较低或年降雨量的方差较高时，这种响应会受到抑制。时不变和随机模型的扰动分析表明，老年女性的招募和生存是人口增长率的关键决定因素。
In this study, we use deterministic and stochastic models to analyze the demography of Verreaux’s sifaka (Propithecus verreauxi verreauxi) in a fluctuating rainfall environment. The model is based on 16 years of data from Beza Mahafaly Special Reserve, southwest Madagascar. The parameters in the stage-classified life cycle were estimated using mark-recapture methods. Statistical models were evaluated using information-theoretic techniques and multi-model inference. The highest ranking model is time-invariant, but the averaged model includes rainfall-dependence of survival and breeding. We used a time-series model of rainfall to construct a stochastic demographic model. The time-invariant model and the stochastic model give a population growth rate of about 0.98. Bootstrap confidence intervals on the growth rates, both deterministic and stochastic, include 1. Growth rates are most elastic to changes in adult survival. Many demographic statistics show a nonlinear response to annual rainfall but are depressed when annual rainfall is low, or the variance in annual rainfall is high. Perturbation analyses from both the time-invariant and stochastic models indicate that recruitment and survival of older females are key determinants of population growth rate.