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

9424625休斯保护生物学的核心问题之一是决定小种群的生存能力。种群的生存能力取决于人口和遗传因素的复杂相互作用。从短期来看，环境引起的人口差异似乎是这些因素中最重要的。从长远来看，种群规模小的遗传后果变得越来越重要。遗传和人口统计学方法都被用来评估种群的生存能力。种群生存能力的遗传评估侧重于有效种群规模。有效大小是理想化种群的大小，其中近亲交配和漂移的随机过程与研究种群中的随机过程起作用的速度相同。许多保护指导方针规定了应该从有效大小方面拯救的个体数量。然而，在几乎每一个野生种群中，有效种群数量都远远小于实际种群数量。人口评估是人口生存能力评估(PVA)持续性模型的结果。在PVA模型中，使用人口学参数的平均值和方差来预测种群的未来：不同年龄或不同阶段的年繁殖成功率和存活率。这个保护和恢复生物学项目将基于对委内瑞拉一种新热带鹦鹉--绿腰鹦鹉的研究，比较遗传和人口统计学方法对生存能力评估的影响。此外，这项研究还将建立该物种鹦鹉种群持久性的人口统计学模型。PVA和其他人口统计模型的使用是保护生物学的基石，但这些方法很少在少量新热带鸟类上进行测试和验证。

9424625 Hughes 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.