The anthropogenic alteration of natural habitats can modify interactions between various biotic and abiotic factors. The prevalence of avian blood parasites in free-living host species in the tropics has shown contrasting patterns in altered landscapes. Here, we investigate these potential associations between understorey insectivorous bird species of the Eastern Himalayas and avian haemosporidians in primary and selectively logged forests. We describe patterns related to host–parasite associations, host life-history traits and host specificity in primary and logged forests. Using parasite-specific cytochrome-b gene markers, we screened 545 individual birds from nine families, 33 genera and 57 species. Of these, 34.67% were infected with Leucocytozoon spp., 13.94% with Haemoproteus spp., 3.30% with Plasmodium spp. and 8.44% with co-infections. We found that parasite prevalence did not change with logging; however, host specificity and life-history traits did have associations with infection prevalence. We report a vertical stratification in genera-specific infections driven by vector groups – upper canopy and midstorey foragers had high Leucocytozoon and Haemoproteus prevalence, respectively. In addition, species foraging in mixed-species flocks showed increased infection risk with Leucocytozoon, whereas solitary foragers had a high prevalence of Plasmodium. This study also highlights that avian parasite lineages are genetically more distinct in primary forest than in logged forest plots. Although our study demonstrates no influence of selective logging on parasite prevalence, it does reflect a positive influence of host abundance and logged habitats on parasite diversity. Our work reveals valuable patterns in terms of phylospecificity and genetic variation in parasite assemblages. Further research with a focus on parasite intensity and vector abundance will help us to understand anthropogenic impacts on parasite transmission dynamics in Eastern Himalayan birds.

中文翻译：

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栖息地质量对印度东喜马拉雅地区下层鸟类食虫动物血液寄生虫组合的影响

自然栖息地的人为改变可以改变各种生物和非生物因素之间的相互作用。热带自由生活宿主物种中禽血寄生虫的流行在改变的景观中显示出对比鲜明的模式。在这里，我们调查了东喜马拉雅山下层食虫鸟类与原始森林和选择性采伐森林中的鸟类血孢子虫之间的这些潜在关联。我们描述了与原始森林和砍伐森林中宿主-寄生虫关联、宿主生活史特征和宿主特异性相关的模式。使用寄生虫特异性细胞色素-b基因标记，我们筛选了来自 9 个科、33 个属和 57 个物种的 545 只鸟。其中，34.67% 感染了白细胞动物属。,13.94％，与Haemoproteus属，3.30％与疟原虫属。8.44% 合并感染。我们发现寄生虫流行率不会随着伐木而改变；然而，宿主特异性和生活史特征确实与感染流行有关。我们报告了由载体群体驱动的属特异性感染的垂直分层——上层树冠和中层觅食者分别具有高白细胞动物和Haemoproteus流行率。此外，在混种群中觅食显示白细胞动物感染风险增加，而单独觅食的疟原虫感染率较高. 这项研究还强调，与砍伐林地相比，原始森林中的鸟类寄生虫谱系在遗传上更明显。尽管我们的研究表明选择性采伐对寄生虫流行没有影响，但它确实反映了寄主丰度和采伐栖息地对寄生虫多样性的积极影响。我们的工作揭示了寄生虫组合的系统特异性和遗传变异方面的宝贵模式。专注于寄生虫强度和载体丰度的进一步研究将帮助我们了解人为对东喜马拉雅鸟类寄生虫传播动态的影响。