Parasites at the Edge of the World: Haemoparasites and Their Tick Vectors in Antarctic Penguins

Abstract

Ticks are vectors of various haemoparasites, including Babesia, Borrelia, and Rickettsia. Despite the documented presence of ticks in Antarctica for several decades, comprehensive data on haemoparasites in both vectors and avian hosts from this region remain limited. The increasing tick population may pose significant health risks to immunologically naïve penguins, underscoring the need for a thorough understanding of parasite prevalence in these ecosystems. We investigated the prevalence and diversity of haemoparasites in Antarctic penguins and their associated ticks. Fieldwork was conducted in several rookeries of Adélie, gentoo, and chinstrap penguins. Ticks were collected from nest surroundings and directly from birds, while blood samples were obtained from both adult penguins and chicks. Samples were preserved appropriately, with ticks stored in 96% ethanol or frozen, and blood samples frozen. Molecular analyses, including PCR and Sanger sequencing, were performed to detect and identify haemoparasites. Results were compared with previous Antarctic studies and global data on penguin haemoparasites to assess regional and worldwide trends. Antarctic wildlife faces multiple ecological pressures, including climate change, anthropogenic disturbances, pollution, and emerging infectious diseases. Understanding the role of parasitic infections is crucial, as they can significantly impact host fitness and breeding success. This study provides new insights into parasite-host dynamics in Antarctic penguins, contributing to a broader understanding of haemoparasitic infections in seabirds and laying the groundwork for future research on their ecological consequences in this fragile environment. This study was funded by the Polish National Science Centre (Grant No. 2022/44/C/NZ6/00142). Corresponding author: k.tolkacz@ibb.waw.pl