The Origin and Diversity of Viruses transported to King George Island via Migratory Birds

Alemán. Migratory animals connect the world. The vast majority of migratory birds undertake journeys towards higher latitudes to breed in the north and south and take advantage of seasonally higher pulses in food supply, less competition and lower predation pressure (Dingle 2014). This has led to distinct major flyways connecting regions across similar longitudinal bands. In the polar regions, global flyways overlap. Thus, the Arctic and Antarctics stand out as hubs where migratory birds from all over the world meet during the breeding season. The connecting movements of birds into the polar regions has likely an effect in the spread and the dynamics of viruses, including pathogens; besides the unparalleled links migratory birds establish across the globe, bird migration involves an immense number of individuals from different taxa, which can lead to an increase in contact rates with other hosts (Altizer et al., 2011). In addition, hosts that move between regions are naturally exposed to parasites and pathogens in multiple regions, with the consequence that migratory species experience a higher diversity of pathogen exposure and infection compared to resident species (Koprivnikar and Leung 2015, Hannon et al., 2016). Ultimately, long-distance migration can be demanding and may include strenuous physical exertion interspersed with periods of frantic energy acquisition and recovery (Piersma and van Gils 2011). These intense physiological demands can result in reduced immune responses rendering migrants more susceptible to infection (Buehler et al., 2010). Therefore, bird migration has the potential to generate superspreader hosts and the polar regions may represent so called hotspots of virus transmission. Yet, due to several reasons, the polar regions and notably Antarctica is largely ignored when it comes to virus surveillance and ultimately to an understanding of the role of polar sites in the global dynamics of wildlife deseases. The major objectives of this project and for the initial fieldwork expedition to King George Island (Fildes Peninsula and Ardley Island) were to sample seabirds during the early arrival season and identify the diversity and origin of transported viruses into the local ecosystem.