Epizootiological survey of avian malaria in the Hawaiian Islands

Typescript.Thesis (Ph. D.)--University of Hawaii, 1970.Bibliography: leaves [60]-65.vi, 65 l tablesAvian malaria is believed to be one of the main factors in the extinction of the native Hawaiian avifauna. An epizoological investigation of the disease was conducted in the Hawaiian Islands primarily to determine whether avian malaria was present in Hawaii. The birds were collected from the islands of Oahu, Maui, Kauai, and Hawaii, at different elevations for a period of three years. Blood samples were taken either from the main wing vein, or from the toe nail. Blood smears were prepared and stained with Giemsa's stain. Histological preparations for the study of the exoerythrocytic stage of the parasites were also made. A total of 4,988 blood smears from 2,604 birds representing 38 species of native and introduced birds was examined. Plasmodium circumflexum Kikuth, P. gallinaceum Brumpt, P. cathemerium Hartman, and probably P. matutinum (Huff), were found in six species of native and introduced birds. Significantly, these records are the first authenticated reports of these parasites from the Pacific Islands, and this is the first time that P. circumflexum has been reported from this part of the world. The presence of P. gallinaceum indicates that this parasite has accompanied its host to many parts of the tropics. Blood smears taken from pigeons and doves indicated that some of these birds were infected with Haemoproteus and Leucocytozoon. It was found that 65 percent of the pigeons were infected with Haemoproteus. The doves, however, did not seem to be infected by this pathogen. Although both pigeons and doves were infected by the Leucocytozoon, the incidence was relatively low. Only four percent of the two species of birds were infected. This is the first record for Leucocytozoon from the Hawaiian Islands. The presence of the larvae of the potential vector of avian malaria, Culex pipiens quinguefasciatus Say, in a water container at 6511 feet elevation indicates that probably one of the limiting factors in the vertical distribution of Culex is the availability of suitable habitats