Blood parasites of prairie anatids and their implication in waterfowl management in Alberta and Saskatchewan.

Information on the blood parasites occurring in 3,866 anatids of 14 species collected from five locations in Alberta and Saskatchewan during 1976-80 is summarized. An overall prevalence of 26% with avian hematozoa was recorded. Leucocytozoon simondi was the most frequently encountered parasite, occurring in 17% of the ducks; Haemoproteus nettionis was observed in 11% of the birds while Plasmodium circumflexum and microfilariae (probably of Splendidofilaria fallisensis) occurred in only 2% and less than 1% of the sample respectively. Overall prevalence of infection in both immatures and adults was similar, although the sample was heavily biased in favor of the immature age class. While the overall prevalence of L. simondi was similar in both age classes, H. nettionis occurred twice as frequently in the adult birds. Infection prevalences of birds in the five geographic areas sampled were different and these differences are discussed. Prevalences also differed from year to year in birds from the various areas and these differences are attributed, in part, to the water levels encountered each year. Leucocytozoon simondi is considered a potentially limiting factor for waterfowl production in some areas of northern Alberta and Saskatchewan.