Department of Biology and Museum of Natural History, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin 54481.
Department of Biology, University of North Dakota, Grand Forks, North Dakota 58202.
J Parasitol. 2024 Oct 1;110(5):445-454. doi: 10.1645/23-109.
Avian haemosporidians are a diverse group of protozoan parasites that infect a wide range of host species. Waterfowl are an ecologically and economically important group of hosts that have been underrepresented in studies of haemosporidians. Diving ducks have unique life history traits, and morphological, behavioral, and dietary differences separate them from more common dabbling ducks. Greater scaup (Aythya marila) and lesser scaup (Aythya affinis) are closely related diving ducks with declining population trends in North America. To better understand the diversity of haemosporidians within diving ducks and factors related to host infections in scaup, we surveyed 82 hunter-donated waterfowl from 8 species of divers, sea ducks, and dabblers from Green Bay, Wisconsin from 2019 to 2021. We used molecular detection methods and phylogenetic and statistical analyses to describe the diversity, host associations, and prevalence of haemosporidians. We detected 14 unique genetic lineages of haemosporidians, including 4 novel lineages. We identified at least 1 lineage of haemosporidian in each of the 8 host species of divers, sea ducks, and dabblers examined. Lesser scaup had more diverse haemosporidian communities than did greater scaup, but lineages showed no clustering among these hosts when incorporated in phylogenetic analyses with lineages from other Nearctic waterfowl. Female lesser scaup had the highest infection prevalence, but there was no effect of host age or year of sampling. Our findings underscore the importance of species and sex differences that could lead to a higher risk of infections. Our results also fill an important geographical sampling gap for haemosporidians along a key migratory route. Increased monitoring of haemosporidians in waterfowl could contribute to insights into parasite evolution and ecology and the conservation and management of host populations.
禽血孢子虫是一组多样的原生动物寄生虫，感染范围广泛宿主物种。水禽是一类具有生态和经济重要性的宿主，在血孢子虫研究中代表性不足。潜水鸭具有独特的生活史特征，形态、行为和饮食上的差异使它们与更常见的涉水鸭分开。大斑头鸭（Aythya marila）和斑头秋沙鸭（Aythya affinis）是密切相关的潜水鸭，其在北美的种群趋势正在下降。为了更好地了解潜水鸭中的血孢子虫多样性以及与斑头鸭宿主感染相关的因素，我们于 2019 年至 2021 年在威斯康星州绿湾调查了来自 8 种潜水鸭、海鸭和涉水鸭的 82 只猎鸭。我们使用分子检测方法和系统发育和统计分析来描述血孢子虫的多样性、宿主关联性和流行率。我们检测到 14 种独特的血孢子虫遗传谱系，包括 4 种新谱系。我们在所检查的 8 种潜水鸭、海鸭和涉水鸭宿主中都鉴定出至少 1 种血孢子虫谱系。斑头秋沙鸭的血孢子虫群落比大斑头鸭更为多样，但在将这些宿主的谱系纳入与其他北美水禽的谱系进行系统发育分析时，它们之间没有谱系聚类。雌性斑头秋沙鸭的感染率最高，但宿主年龄或采样年份没有影响。我们的研究结果强调了物种和性别差异的重要性，这可能导致感染风险增加。我们的研究结果还填补了沿关键迁徙路线对血孢子虫进行地理采样的重要空白。增加对水禽中血孢子虫的监测可以为了解寄生虫进化和生态学以及宿主种群的保护和管理提供帮助。
