BLOOD PARASITES IN BIRDS FROM MONTEVERDE, COSTA-RICA

In a survey of avian blood parasites in Costa Rica, 51 (11%,) of 479 b irds sampled were infected by at least one species of hematozoan. Four teen of the 60 species of birds in the survey were examined for the fi rst time. Infections were most common in ramphastids and emberizids an d infrequent in other taxa. Among resident species, infections were mo re commonly detected during the wet season when most birds breed than during the dry season when few birds breed. Infections caused by Haemo proteus sp. were most common, while Plasmodium sp., Leucocytozoon sp., Trypanosoma sp., and microfilarial infections were rare. The intensit y of the 40 Haemoproteus infections in adult birds was low, with a mea n +/- SE of 12.5 +/- 3.7 infected cells per 10,000. Haemoproteus infec tions did not undergo seasonal changes in intensity.