Avian Lankesterella infections in Algonquin Park, Ontario

Abstract

During 1966–69 mortality attributed to Lankesterella infections occurred among evening grosbeaks (Hesperiphona vespertina) in Algonquin Park, Ontario. Peak mortality was recorded between mid-June and mid-July in all four years, being highest in 1967. The parasite was subsequently discovered in wild rose-breasted grosbeaks (Pheucticus ludovicianus) and was artificially transmitted to other passerines (though not to a duck) by inoculating infected tissues. Mites from two infected grosbeaks failed to initiate infections when fed to uninfected birds, Isospora oocysts from the feces of grosbeaks were not infective to canaries. The ultrastructure of the parasite in grosbeaks is similar to other eimeriid coccidia. The generic nature of this parasite is discussed in light of recent reports that the species of Lankesterella (= Atoxoplasma) in house sparrows might really be referable to Isospora.