Abundance and diversity of haemosporidian parasites dramatically differ among closely related vireo species

Wiley et al., 2025 (in prep) Abundance and diversity of haemosporidian parasites dramatically differ among closely related vireo species.In this study, we use pectoral tissues and whole blood samples of three closely related, elevational replacement species of vireo to characterize infection dynamics of avian Haemosporidians across their summer breeding sites in the American Southwest. We asked: What is the distribution, prevalence, and pathogen loads (parasitemia) experienced across these closely related species (Bell’s vireo: n = 20, gray vireo: n = 170, and plumbeous vireo: n = 58) during their breeding season in the southwestern U.S.? And what factors (i.e. host traits: species; environmental factors: temperature, precipitation; geographic features: latitude, elevation) are correlate with infection status and parasitemia?Data are archived on FigShare: https://doi.org/10.6084/m9.figshare.28585943DATASET All birds were sampled during summer months (May–August) spanning the years 1995–2019 across 27 unique sites in New Mexico and a single site in Utah, under appropriate federal, state, and local permits. Majority of samples were accompanied by vouchered specimens that were archived at the Museum of Southwestern Biology (MSB), University of New Mexico (UNM), except in the case of gray vireos that were released after sample collection. Samples used in this study represent 248 wild birds of three closely related vireo species (Bell’s vireo: n = 20, gray vireo: n = 170, and plumbeous vireo: n = 58). We screened samples via nested PCR amplification of the cytochrome b region for Haemoproteus and Plasmodium parasites and positive infections were quantified via microscopy following the protocol described in Valkiūnas (2005). Parasitemia represents the % of parasites counted across 10,000 red blood cells screened.We identified and compared haplotypes to published records stored in the public databases GenBank (National Center for Biotechnology Information, US National Library of Medicine) and MalAvi (Bensch et al., 2009). Haplotypes that differed by one or more base pairs (~0.2% sequence divergence) from published sequences on GenBank or MalAvi were considered novel and named following MalAvi conventions. All sequences are uploaded to GenBank and MalAvi under [Accession Number #####] & [Accession Number #####].Additionally, we documented aspects of sampling locality (i.e. latitude, longitude, elevation), and environmental factors known to impact pathogen prevalence and distribution (i.e. WORLDCLIM 19 bioclimatic variables to do with temperature and precipitation).Analysis code is available on GitHub: https://github.com/dlfwiley/Vireo-Malaria-Project. Majority of data, except in the case of gray vireos released after sample collection, are linked to vouchered host and parasite specimens, housed at the Museum of Southwestern Biology (MSB) at the University of New Mexico, USA. Specimen records are accessible in the Artcos database (https://arctos.database.museum/).

Wiley等（2025，待发表）：血孢子虫（haemosporidian）的丰度与多样性在近缘莺雀物种间存在显著差异。本研究选取三种近缘、沿海拔梯度替代分布的莺雀物种的胸组织与全血样本，旨在表征鸟类血孢子虫在其美国西南部夏季繁殖地的感染动态。本研究旨在解答两个问题：其一，美国西南部繁殖季期间，上述三种近缘莺雀物种（贝尔氏莺雀：n=20、灰莺雀：n=170、铅色莺雀：n=58）的感染分布、流行率、病原体载量与寄生虫血症（parasitemia）情况如何？其二，哪些因素（宿主性状：物种；环境因子：温度、降水量；地理特征：纬度、海拔）与感染状态及寄生虫血症相关？本研究数据已存档于FigShare：https://doi.org/10.6084/m9.figshare.28585943。数据集：所有鸟类样本采集于1995-2019年的夏季（5月至8月），覆盖新墨西哥州27个独立采样点与犹他州1个采样点，采样工作已获得相应联邦、州及地方许可。大部分样本附带凭证标本，存档于新墨西哥大学（UNM）西南生物学博物馆（MSB）；仅灰莺雀在完成采样后被放生。本研究共纳入248只野生鸟类样本，分属上述三种近缘莺雀物种。我们通过嵌套聚合酶链反应（nested PCR）扩增细胞色素b（cytochrome b）区域，筛查嗜血寄生虫（Haemoproteus）与疟原虫（Plasmodium）感染；阳性感染的载量通过显微镜计数完成，检测流程遵循Valkiūnas（2005）发表的方案。寄生虫血症指每10000个被筛查的红细胞中检出的寄生虫占比。我们将检出的单倍型与公共数据库GenBank（美国国家生物技术信息中心，美国国立医学图书馆）及MalAvi（Bensch等，2009）中的已发表记录进行比对。与GenBank或MalAvi中已发表序列存在一个或多个碱基对差异（序列分歧度约0.2%）的单倍型被认定为新单倍型，并遵循MalAvi命名规则进行命名。所有序列已上传至GenBank与MalAvi，登录号分别为[#####]与[#####]。此外，我们记录了采样点的相关信息（纬度、经度、海拔），以及已知会影响病原体流行率与分布的环境因子：即世界气候（WORLDCLIM）19个温度与降水相关生物气候变量。本研究的分析代码已公开于GitHub：https://github.com/dlfwiley/Vireo-Malaria-Project。除采样后放生的灰莺雀样本外，大部分数据均关联有凭证宿主及寄生虫标本，馆藏于美国新墨西哥大学西南生物学博物馆（MSB）。标本记录可通过Artcos数据库（https://arctos.database.museum/）获取。