计算有效种群大小估计值(Ne)的分子方法越来越多地用作对野生动植物种群进行长期人口监测的替代方法。然而,大多数长寿物种的复杂生态以及随之而来的模型假设的不确定性意味着有效的种群规模估计通常是不精确的。尽管存在将年龄结构纳入世代重叠的长寿命物种的Ne估计的方法,由于缺乏大多数野生种群的相关信息,它们很少使用。这里,我们对一只难以捉摸的林地蝙蝠进行了案例研究,Myotisbechsteinii,为了比较使用亲子关系分配Ne估计器(EPA)与更常用的连锁不平衡(LD)Ne估计器来检测长期人口趋势,并评估了部署不同总体样本量的影响。我们使用了之前发表的一项研究的基因型数据,并使用该物种的生活史特征模拟了150多年来48种不同的人口统计学情景。LD方法大大优于EPA方法。不出所料,样本量较小导致检测人口趋势的能力下降。然而,即使测试的最小样本量(n=30)也可以用LD方法检测到重要的变化(下降60%-80%)。这些结果表明,遗传方法可以成为监测长寿物种的有效方法。比如蝙蝠,只要它们是几十年来进行的。
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, Myotis bechsteinii, 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 (n = 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.