Low prevalence of haemosporidian parasites in resident Greylag Geese ( Anser anser ) in southwestern Germany

Greylag Geese ( Anser anser , Anatidae) are associated with water throughout their life and are, therefore, frequently exposed to avian malaria vectors such as mosquitoes (Culicidae) and black flies (Simuliidae). Thus, they could serve as reservoir for avian malaria parasites (Haemosporida). We examined 143 blood samples from individually ringed geese in a sedentary flock in Stuttgart, southwestern Germany, for the prevalence of Haemosporida including Plasmodium , Haemoproteus and Leucocytozoon , using established and newly developed PCR protocols. Only one adult female goose was infected with Plasmodium sp. GRW04 (AF254975.1), a lineage that is part of the morphospecies Plasmodium ( Haemamoeba ) relictum , which has a worldwide distribution. This is the first time this parasite lineage was detected in the Anseriformes. Our findings support the hypothesis that the transmission of this strain occurred in mainland Europe and is not restricted to wintering areas outside Europe as previously suggested. We discuss the low haemosporidian prevalence detected in the examined goose population in the light of other studies on waterbirds.