CRB: Collaborative Research: Comparing Genetic and Demographic Models of Population Viability for a Neotropical Parrot

9503194 Beissenger保护生物学的核心问题之一是确定小种群的生存能力。种群生存能力取决于人口统计学和遗传因素的复杂相互作用。在短期内，环境引起的人口变化似乎是这些因素中最重要的。从长远来看，小种群规模的遗传后果变得越来越重要。遗传学和人口统计学方法都用于评估种群生存能力。种群生存力的遗传评估侧重于有效种群规模。有效大小是一个理想化群体的大小，其中近亲繁殖和漂移的随机过程以与研究群体相同的速率起作用。许多关于保护的指导方针都规定了应该根据有效大小保存的个体数量。然而，在几乎每一个野生种群中，有效规模都比实际种群规模小得多。人口统计学评估结果来自种群生存力评估（PVA）模型的持久性。在PVA模型中，使用人口统计参数的均值和方差来预测未来的人口：不同年龄或阶段类别的年度繁殖成功率和存活率。这一保护和恢复生物学项目将比较遗传和人口统计方法，以根据对委内瑞拉新热带鹦鹉绿腰鹦鹉的研究进行可行性评估。此外，这项研究将开发一个人口模型的人口持久性，这种鹦鹉。PVA和其他人口模型的使用是保护生物学的基石，但这些方法很少在新热带区鸟类的小种群上进行测试和验证。

9503194 Beissenger One of the central problems in conservation biology is determining the viability of small populations. Population viability is dependent on complex interactions of demographic and genetic factors. Over the short term demographic variation induced by the environment seems to be the most important of these factors. Over the long term the genetic consequences of small population size become increasingly important. Both genetic and demographic methods are used to assess population viability. Genetic assessments of population viability focus on effective population size. The effective size is the size of an idealized population in which the random processes of inbreeding and drift act at the same rate as they do in the study population. Many guidelines for conservation state the number of individuals that should be saved in terms of effective size. Yet, in almost every wild population, effective size is much smaller than actual population size. Demographic assessments result from population viability assessment (PVA) models of persistence. In PVA models, populations are projected into the future using means and variances of demographic parameters: annual reproductive success and survivorship for different age or stage classes. This conservation and restoration biology project will compare genetic and demographic approaches to viability assessment based on studies of a Neotropical parrot, the Green-rumped Parrotlet in Venezuela. In addition, this research will develop a demographic model of population persistence for this species of parrot. The use of PVA and other demographic models is a cornerstone in conservation biology, yet the methods have rarely been tested and verified on small populations of neotropical birds.