BLOOD PARASITES OF BIRDS IN ALGONQUIN PARK, CANADA, AND A DISCUSSION OF THEIR TRANSMISSION

Abstract

Fixed and stained blood smears of over 3000 birds resident in Algonquin Park, Canada, have been examined for blood parasites. Sixty per cent of the adults and 40% of the immature birds harbored one or more blood parasites. Leucocytozoon occurred in 60%, Trypanosoma in 48%, Haemoproteus in 26%, Microfilaria in 7%, and Plasmodium in 2% of the infected birds. High incidence and high parasitaemia of Leucocytozoon, Trypanosoma, and Haemoproteus coincided with the occurrence of large numbers of ornithophilic simuliids and Culicoides and preceded the time when most hippoboscids were recovered. Differences in incidence of parasites and the level of parasitaemia in different birds when considered in relation to the occurrence and feeding behavior of various ornithophilic flies suggest that simuliids are the vectors of Trypanosoma, and Culicoides transmit Haemoproteus in this area.