Snails can survive passage through a bird's digestive system
Snails can survive passage through a bird's digestive system
复制标题
DOI：
10.1111/j.1365-2699.2011.02559.x
复制
发表时间：
2012-01-01
影响因子：
3.9
通讯作者：
Chiba, Satoshi
中科院分区：
文献类型：
--
作者：
Wada, Shinichiro;Kawakami, Kazuto;Chiba, Satoshi
目的捕食通常被视为限制动物被捕食物种分布的一个因素。然而，在某些情况下，例如种子传播，捕食可能会增强被捕食物种的传播能力。在之前的一项研究中，我们发现陆地蜗牛在小川群岛被日本白眼(Zosterops Japan Onicus)和褐耳白头翁(Hypsipetes Amaurotis)捕食。本文提供了实验和野外证据，表明陆螺可能通过鸟类捕食而传播。位于西太平洋小川群岛的Hahajima岛。方法首先进行实验，测试陆螺Tornatellides boeningi在吞食并通过鸟类消化系统后是否还能存活。其次，为了研究这种钉螺在鸟类内部迁移和扩散的潜在作用，我们调查了钉螺种群遗传多样性的分布与捕食性鸟类的区域地理丰度之间的关系。用Arlequin法对白背飞虱种群遗传结构和距离隔离进行了推断。用广义线性混合模型检验了布氏毛虫种群核苷酸多样性与捕食者种群密度之间的关系。我们对完全模型和去除固定效应的另一个模型进行了似然比检验。结果，在119只日本白眼螺和55只褐耳球钉螺中，分别有14.3%和16.4%的钉螺通过了肠道。此外，一只蜗牛从鸟的肠道里出来后生下了幼崽。用AMOVA分析结果表明，白纹伊蚊在Hahajima上的种群间存在显著的异质性，但没有距离隔离的证据。种群间和种群内线粒体DNA变异水平与野外日本白眼蜂密度呈正相关。主要结论鸟类捕食可能是日本田螺的一种扩散方式，鸟媒扩散在陆生钉螺种群结构中起一定作用。
Aim Predation is generally viewed as a factor that limits the distribution of animal prey species. However, in certain instances, such as seed dispersal, predation may enhance the dispersal capability of prey species. In a prior study, we found that land snails are preyed upon by the Japanese white-eye (Zosterops japonicus) and the brown-eared bulbul (Hypsipetes amaurotis) in the Ogasawara Islands. In this paper we provide experimental and field evidence indicating that land snails could potentially be dispersed through bird predation.Location Hahajima Island of the Ogasawara Islands in the western Pacific.Methods Experimentation was first performed to test whether the land snail Tornatellides boeningi could remain alive after being swallowed and passed through the bird digestive system. Next, in order to investigate the potential role of internal bird transport and dispersal of this snail, we investigated the relationship between the distribution of population genetic diversity in the snail and the regional geographical abundance of predatory birds. The population genetic structure of T. boeningi and isolation by distance were inferred with Arlequin. The association between nucleotide diversity in T. boeningi populations and population density of predators was examined using a generalized linear mixed model. We conducted a likelihood ratio test for the full model and for another model that removed the fixed effect.Results Of the 119 snails fed to Japanese white-eyes and 55 snails fed to brown-eared bulbuls, 14.3% and 16.4% of the snails, respectively, passed through the gut alive. Additionally, one snail gave birth to juveniles after emerging from a bird's gut. Significant heterogeneity among the populations of T. boeningi on Hahajima was indicated using AMOVA; however, there was no evidence of isolation by distance. A positive correlation was found between levels of mitochondrial DNA variation among and within T. boeningi populations and the density of Japanese white-eyes in the wild.Main conclusions Bird predation appears to be a method of dispersal for T. boeningi, and our results suggest that bird-mediated dispersal plays a role in land snail population structure.