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?

这项研究涉及利用统计学来研究动物种群动态和其他生态问题。这项研究的动机是生态学家遇到的实际问题。许多研究涉及捕获-再捕获实验。在这些实验中，动物被捕获、标记、释放，然后被重新捕获或重新观察。捕获和重新捕获/重新观察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以及其他种群参数。 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小鲑鱼被捕食导致补偿性死亡”等问题。在这种情况下，数千条小鲑鱼被贴上 PIT（无源集成应答器）标签，这些标签带有许多水坝上的探测器，这些小鲑鱼在下游迁徙和成年返回时会遇到这些水坝。过去 20 年来，随着流域内燕鸥和鸬鹚数量的扩大，鸟类的捕食量一直在稳步增加。捕食压力在一年内也会发生变化。一些被捕食的小鲑鱼的标签可以在鸟类群落上检测到，作为鸟类捕食的衡量标准（在调整群落上的沉积和检测效率后）。这是一个自然的实验，可以研究鸟类捕食者造成的死亡率与所有其他死亡原因之间的关系。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临灭绝的种群。 适用于此类数据的标准统计方法不足以区分补偿死亡率与亚组间生存的异质性、看起来像补偿死亡率的人为因素（例如抽样相关性）以及竞争风险引入的偏差。需要复杂的贝叶斯模型来消除这些影响。此外，大型数据集（过去 20 年已标记了数百万条小鲑鱼）给使用贝叶斯模型拟合数据带来了计算挑战。还存在修改探测器阵列安装位置的机会，这可能会显着提高检测补偿效应的效率——与简单地增加标记工作相比，可以预期有多大的改进，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情况，这些情况存在不同的死亡来源，并且需要选择管理行动来提高生命周期不同部分的生存率。是否有证据表明管理行动会产生影响？生命周期的哪个阶段是实施此类操作的最佳位置？