Disentangling density-dependent dynamics using full annual cycle models and Bayesian model weight updating

Density dependence regulates populations of many species across all taxonomic groups. Understanding density dependence is vital for predicting the effects of climate, habitat loss and/or management actions on wild populations. Migratory species likely experience seasonal changes in the relative influence of density dependence on population processes such as survival and recruitment throughout the annual cycle. These effects must be accounted for when characterizing migratory populations via population models.
To evaluate effects of density on seasonal survival and recruitment of a migratory species, we used an existing full annual cycle model framework for American black ducks Anas rubripes, and tested different density effects (including no effects) on survival and recruitment. We then used a Bayesian model weight updating routine to determine which population model best fit observed breeding population survey data between 1990 and 2014.
The models that best fit the survey data sugge...

密度依赖（density dependence）调控着所有分类群中诸多物种的种群动态。明晰密度依赖机制，对于预测气候、栖息地丧失及各类管理措施对野生物种种群的影响至关重要。迁徙物种在全年生活周期内，其种群过程（如存活与种群补充（recruitment））受密度依赖影响的相对强弱会呈现季节性变化。在借助种群模型刻画迁徙物种种群特征时，必须将这类影响纳入考量范畴。
为评估密度对某迁徙物种种群季节性存活与种群补充的影响，我们以美洲黑鸭（Anas rubripes）现有全年生活周期模型框架为基础，针对存活与种群补充过程测试了多种密度效应情景（包括无密度效应）。随后我们采用贝叶斯模型权重更新（Bayesian model weight updating）程序，筛选出最适配1990年至2014年间观测到的繁殖种群调查数据的种群模型。
最适配调查数据的模型结果表明……