Over a several year period, the Fort Worth Zoo, Texas, has suffered multiple losses in its avian collection due to the hemoprotozoan parasites, Haemoproteus spp. and Plasmodium spp. Seven cases were confirmed using molecular methods to amplify a mitochondrial cytochrome b gene that is well conserved among these genera. To design an intervention strategy, we examined multiple components of the possible transmission patterns specific to the Fort Worth Zoo. We surveyed the zoo environment, sampled potential vectors of the parasites, and screened blood samples from apparently healthy birds to identify resident carriers. Five insect sampling sites were chosen based on proximity to potential insect breeding sites or past bird fatalities. Insects were caught on at least 3 separate dates using miniature CDC CO2 baited light traps. Trapped insects were sorted based on taxonomic features. Of the over 650 female mosquitoes caught, 150 were identified as members of the genus Culex. Over 75 flies in the genus Culicoides (Ceratopogonidae) were caught and speciated. DNA has been extracted from individual flies and is being tested for the presence of the parasites using PCR. To identify birds within the zoo collection with subclinical parasitic infections, we obtained bird blood samples from the zoo veterinary staff and employed the same molecular methods. To date, one yellow-bellied laughing thrush (Garrulax galbanus) has been identified as a carrier of Plasmodium.