Prevalence of Blood Parasites in Migrating and Wintering California Hawks

Abstract

Abstract Infectious diseases can potentially affect the seasonal migration of hawks. We tested three species of California hawks from autumn 2004 to spring 2006 for haemosporidian blood parasites (Plasmodium, Haemoproteus, and Leucocytozoon spp.). We screened 323 Red-tailed Hawks (Buteo jamaicensis), 100 Cooper's Hawks (Accipiter cooperii), and 21 Red-shouldered Hawks (B. lineatus) for blood parasites using polymerase chain reaction (PCR). Among these hawks, 221 (50%) were infected with Haemoproteus, 134 (30%) with Leucocytozoon, and none with Plasmodium species. We compared blood parasite prevalence results to identify infection patterns in two populations (birds captured during autumn at a migration watchsite in the Marin Headlands [Golden Gate Raptor Observatory] vs. birds captured during winter in the Central Valley) and between years, seasonal periods, and sex and age classes. In 2004, Marin Red-tailed Hawks were more likely to test positive for blood parasites if sampled late in the migration; howev...