Investigation of blood parasites of pygoscelid penguins at the King George and Elephant Islands, South Shetlands Archipelago, Antarctica

Parasites may adversely affect the breeding success and survival of penguins, potentially hampering the viability of their populations. We examined 161 pygoscelid penguins (3 Pygoscelis adeliae, 98 Pygoscelis antarcticus, and 60 Pygoscelis papua) at the South Shetlands Archipelago during the 2010–2011 summer; blood smears were examined for 64 penguins (2 P. adeliae, 18 P. antarcticus, and 44 P. papua), and a PCR test targeting Haemoproteus sp. and Plasmodium sp. was applied for 37 penguins (2 P. adeliae, 17 P. antarcticus, 19 P. papua). No blood parasites were observed, and all PCR tests were negative, leukocyte profiles were similar to those reported in other studies for wild pygoscelid penguins, and all penguins were in good body condition and had no external signs of disease. One specimen of chewing lice (Austrogoniodes sp.) was recorded in one P. antarcticus at King George Island. Ticks (Ixodes uriae) were not observed on the penguins, but were found on the ground near P. antarcticus nests at King George Island. The absence of avian blood parasites in Antarctic penguins is thought to result from the absence of competent invertebrate hosts in the climatic conditions. Predicted climate changes may redefine the geographic distribution of vector-borne pathogens, and therefore, the occurrence of blood parasites and their invertebrate hosts should be monitored regularly in Antarctic birds, particularly in the northernmost Antarctic Peninsula.