Wright Patrick G R, Schofield Henry, Mathews Fiona
Department of Life Sciences University of Sussex Falmer UK.
Vincent Wildlife Trust Ledbury UK.
Ecol Evol. 2021 Feb 3;11(5):2015-2023. doi: 10.1002/ece3.7143. eCollection 2021 Mar.
Molecular approaches to calculate effective population size estimates (Ne) are increasingly used as an alternative to long-term demographic monitoring of wildlife populations. However, the complex ecology of most long-lived species and the consequent uncertainties in model assumptions means that effective population size estimates are often imprecise. Although methods exist to incorporate age structure into Ne estimations for long-lived species with overlapping generations, they are rarely used owing to the lack of relevant information for most wild populations. Here, we performed a case study on an elusive woodland bat, , to compare the use of the parentage assignment Ne estimator (EPA) with the more commonly used linkage disequilibrium (LD) Ne estimator in detecting long-term population trends, and assessed the impacts of deploying different overall sample sizes. We used genotypic data from a previously published study, and simulated 48 contrasting demographic scenarios over 150 years using the life history characteristics of this species The LD method strongly outperformed the EPA method. As expected, smaller sample sizes resulted in a reduced ability to detect population trends. Nevertheless, even the smallest sample size tested ( = 30) could detect important changes (60%-80% decline) with the LD method. These results demonstrate that genetic approaches can be an effective way to monitor long-lived species, such as bats, provided that they are undertaken over multiple decades.
计算有效种群大小估计值（Ne）的分子方法越来越多地被用作野生动物种群长期人口监测的替代方法。然而，大多数长寿物种复杂的生态以及模型假设中随之而来的不确定性意味着有效种群大小估计值往往不准确。尽管存在将年龄结构纳入具有重叠世代的长寿物种Ne估计的方法，但由于大多数野生种群缺乏相关信息，这些方法很少被使用。在这里，我们对一种难以捉摸的林地蝙蝠进行了案例研究，比较在检测长期种群趋势时亲权分配Ne估计器（EPA）与更常用的连锁不平衡（LD）Ne估计器的使用情况，并评估了采用不同总体样本量的影响。我们使用了先前发表研究中的基因型数据，并根据该物种的生活史特征模拟了150年中48种对比的种群统计情景。LD方法明显优于EPA方法。正如预期的那样，较小的样本量导致检测种群趋势的能力下降。然而，即使是测试的最小样本量（n = 30），使用LD方法也能检测到重要变化（下降60%-80%）。这些结果表明，只要进行数十年的监测，遗传方法可以成为监测蝙蝠等长寿物种的有效方法。
