RESUMEN
A total of 1650 birds of 56 species representing 21 families (primarily Passeriformes), was examined for blood parasites in the Lorraine region of France. Only 120 (7.3%) birds were infected, with members of the Paridae, Sylviidae and Turdidae the most frequently parasitized. Haemoproteids were the most commonly encountered parasites followed by the leucocytozoids. Other avian hematozoon genera were uncommon. Prevalence of parasitism was closely similar each year over a three-year period. Immature birds were first noted to be infected with Leucocytozoon in mid-June, suggesting transmission in late May to early June. Haemoproteids were first noted in immature birds in early July, suggesting transmission in mid-June. A review of the literature indicates that the prevalence of parasitism by avian blood parasites has decreased in western Europe since the turn of the century and is currently much lower than the prevalence encountered in Scandinavia, central Russia and eastern North America.