Apparent Absence of Blood Parasites in the Patagonian Seabird Community: Is it Related to the Marine Environment?

-The geographic and specific distribution of avian Haematozoa is poorly understood and much basic information is still needed. Studies of blood parasites in avian communities are scarce despite of their potential for disentangling the relative importance of host-specific and ecological factors shaping blood parasite distributions. Here we present the first study of blood parasites in a breeding community of seabirds by scanning blood smears obtained from 560 birds belonging to 13 species breeding in Patagonia, Argentina. Seven of these species have not been sampled previously for blood parasites. No blood parasites were detected. The scarcity of vectors due to the marine environment and the dry conditions around the colonies is the most plausible hypothesis for explaining the apparent absence of blood parasites in the Patagonian seabird community, although other hypotheses should be examined. Received 12 December 2000, accepted 8 May 2001.