Capture-recapture modelling of population dynamics

种群动态的捕获-再捕获模型

• 批准号: RGPIN-2017-03883
• 负责人: Schwarz, Carl
• 金额: $ 1.46万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710596
• 关键词: Capture; recapture; modelling; population; dynamics

This research involves the use of statistics in studying the dynamics of animal populations and other ecological problems. The research is motivated by real problems encountered by ecologists. Much of the research involves capture-recapture experiments. In these experiments, animals are captured, tagged, released and then subsequently recaptured or resighted. The pattern of captures and recaptures/resightings enables the researcher to estimate survival rates, the number of animals present in the population and other population parameters. The research aims to develop new statistical methodology to help answer questions such as "Is there evidence of compensatory mortality from predation of smolts in the Columbia River Basin." In such cases, many thousands of smolts are tagged with PIT (passive integrated transponder) tags with detectors on many dams that the smolts encounter during their downstream migration and their return as adults. Avian predation has been steadily increasing over the last 20 years with the expansion of tern and cormorant colonies in the basin. Predation pressure also varies within a year. The tags from some predated smolts can be detected on the avian colonies as a measure of avian predation (after adjusting for deposition and detection efficiency on the colonies). This makes a natural experiment to investigate the relationship between mortality due to avian predators and all other sources of mortality. If there is no relationship, then predator controls may have little impact on subsequent returns of adult fish and other methods may be needed to help restore endangered stocks. Standard statistical methods applied to this type of data are inadequate to to distinguish compensatory mortality from heterogeneity in survival among subgroups, artefacts that look like compensatory mortality such as sampling correlation, and biases introduced from competing risks. Complex Bayesian models are needed to disentangle these effects. Furthermore, the large dataset (millions of smolts have been marked over the last 20 years) introduces computational challenges in using fitting a Bayesian model to the data. Opportunities are also present to modify where detector arrays are installed which may lead to dramatic improvements in efficiency to detect compensatory effects -- just how big of an improvement can be expected and is it cost effective compared to simply increasing tagging efforts? The statistical methods methods developed are broadly applicable in many wildlife management situations where there are different sources of mortality and a choice of management actions to increase survival at different parts of the life cycle. Is there evidence that the management action would have any impact? As what stage in the lifecycle is the best place to implement such actions?

这项研究涉及使用统计学来研究动物种群的动态和其他生态问题。这项研究的动机是生态学家遇到的真实的问题。许多研究都涉及捕获-再捕获实验。在这些实验中，动物被捕获，标记，释放，然后重新捕获或重新分配。捕获和重新捕获/重新定位的模式使研究人员能够估计存活率，种群中存在的动物数量和其他种群参数。 该研究旨在开发新的统计方法，以帮助回答诸如“是否有证据表明哥伦比亚河流域的小鲑鱼被捕食造成了补偿性死亡”之类的问题。“在这种情况下，成千上万的小鲑鱼被贴上了PIT（被动集成转发器）标签，在小鲑鱼下游迁移和成年返回时遇到的许多水坝上都有探测器。在过去的20年里，随着燕鸥和鸬鹚在该盆地的殖民地的扩大，鸟类的捕食一直在稳步增加。捕食压力在一年内也会有所不同。来自一些捕食的小鲑鱼的标签可以在禽类菌落上检测到，作为禽类捕食的量度（在调整菌落上的沉积和检测效率之后）。这是一个自然的实验，研究鸟类捕食者死亡率与所有其他死亡率来源之间的关系。如果没有关系，那么捕食者控制可能对成鱼随后的回归影响不大，可能需要其他方法来帮助恢复濒危种群。 适用于这类数据的标准统计方法不足以区分补偿性死亡率与亚组间生存异质性、看似补偿性死亡率的人为因素（如抽样相关性）以及竞争风险引入的偏倚。需要复杂的贝叶斯模型来理清这些影响。此外，大型数据集（在过去20年中标记了数百万只小鲑鱼）在使用贝叶斯模型拟合数据时引入了计算挑战。还有机会修改探测器阵列的安装位置，这可能会大大提高探测补偿效应的效率-究竟可以预期多大的改进，与简单地增加标记工作相比，它是否具有成本效益？ 所开发的统计方法广泛适用于许多野生动物管理的情况下，有不同的死亡率来源和管理行动的选择，以增加生存在生命周期的不同部分。是否有证据表明管理层的行动会产生任何影响？生命周期中的哪个阶段是实现这些操作的最佳位置？