Identification of Blood Parasites in Old World Warbler Species from the Danube River Delta

Warbler species of the families Sylviidae and Acrocephalidae occurring in the Danube river delta are frequently exposed to blood-sucking arthropods that transmit avian blood parasites. We investigated infections by three genera of hemosporidian parasites in blood samples from six warbler species. Altogether in 17 (32.6%) of 52 blood samples, a PCR product was amplified. The great reed warbler (Acrocephalus arundinaceus) had the highest prevalence, with 63.6% (7/11) infected individuals, whereas no infection was detected in marsh warbler (Acrocephalus palustris). The most common parasite genus was Haemoproteus, which was found in 15.4% (8/52) of individuals. Seven known parasite lineages (five Haemoproteus and two Plasmodium) and two new lineages were recorded (one Leucocytozoon and one Plasmodium).