A COMPARISON OF AVIAN HEMATOZOAN EPIZOOTIOLOGY IN 2 CALIFORNIA COASTAL SCRUB COMMUNITIES

Passerine birds within two California (USA) coastal scrub ecosystems, an island and a mainland site, were examined for hematozoa from 1984 t o 1990. Island birds had a significantly lower hematozoan prevalence t han mainland birds. This prevalence difference can be related to a lac k of appropriate hematozoan vectors on the island. Haemoproteus spp. a nd Leucocytozoon spp. were the most commonly encountered hematozoa; fo ur new species of Leucocytozoon spp. and one new Haemoproteus sp. were found in five host families. No transmission of hematozoan parasites was detected at the island site during the study. At the mainland coas tal scrub site, Leucocytozoon spp, was transmitted each year while Pla smodium spp. and Haemoproteus spp. transmission varied between years. There was evidence that some species of birds acquired infections outs ide of their breeding season. Results of this study lend further suppo rt to the prediction of decreased disease on remote island ecosystems.