Prevalence and New Host Records of Avian Blood Parasites in Songbirds from the West of Iran: Insights into Haemosporidian Infections and the Impact of Humidity

Haemosporidian parasites, including Haemoproteus, Plasmodium, and Leucocytozoon, are intracellular parasites found in the blood and tissues of birds worldwide. The prevalence of these parasites varies depending on bird species and habitats. Humidity, influenced by water availability, is one of the factors affecting their prevalence. In this study, we collected 145 blood samples from wild songbirds in the western region of Iran from April to November 2021-2022. Blood smears were prepared using the push-slide method and stained with Giemsa. The stained smears were examined under a light microscope. Among the seven songbird families sampled, blood parasites were detected in 31 individuals from five families. Of these, 23 individuals (15.86%) were from humid areas, while 8 individuals (5.51%) were from dry areas. The highest infection rates were observed in the Paridae (9.65%) and Motacilliidae (4.82%) families, while the lowest infection rates were found in the Corvidae (1.37%) and Acrocephalidae (1.37%) families. We recorded two new hosts for Leucocytozoon spp. (Motacilla flava and Acrocephalus melanopogon) for the first time in the world and four new host records (Motacilla flava, Pica pica, Acrocephalus melanopogon, and Acrocephalus agricola) for blood parasites in the west of Iran. Our findings highlight the high prevalence of avian blood parasites in songbirds inhabiting humid areas, suggesting that these environments provide suitable conditions for the growth and reproduction of invertebrate hosts.