Document Type



Avian Blood Parasites, Hematozoa, Plasmodium relictum


Hematozoa are reported from 171 birds, representing 7 orders of 20 families and 33 species, all collected in Dickinson County, northwest Iowa, with the majority of animals being collected at the Iowa Lakeside Laboratory, Milford, Iowa. Blood parasites were observed in 67 birds (39.2%), with an incidence as follows: Haemoproteus sp., 45 (26.3%); Leucocytozoon sp., 19 (11.1%); Plasmodium sp., 4 (2.3%); Trypanosoma 3 (1.7%); and microfilariae, 29 (16.9%). An evaluation of these results indicates a dramatic decrease in the incidence of blood parasites later in the summer. The presence of parasites early in the spring is considered to be a function of relapse in birds returning to the area to build nests and to reproduce. The subsequent decrease in incidence of parasitized birds occurs as the infections run their course and become latent. A species of Plasmodium isolated from a blue jay (Cyanocita cristata) was found to be highly pathogenic, since the natural host as well as two other blue jays with induced blood infections died, with over 60% of their erythrocytes being parasitized. Using gametocyte morphology, the number of merozoites in mature schizonts and the punctiform appearance of pigment, the parasite was considered to be P. relictum. The blue jay appears to be a new host record for this parasite, at least in Iowa.

Publication Date

July 1975

Journal Title

Proceedings of the Iowa Academy of Science





First Page


Last Page



©1975 Iowa Academy of Science, Inc.



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