LAUSR

1. The spatial structure of host communities is expected to constrain pathogen spread. However, predators and/or scavengers may connect distant host (sub)populations when foraging. Determining whether some individuals or populations play a prominent role in the spread of pathogens is critical to inform management measures. 2. We explored movements and epidemiological status of brown skuas (Stercorarius antarcticus), the only avian terrestrial consumer native of Amsterdam Island (Indian Ocean), to assess whether and how they could be involved in the spread of the bacterium Pasteurella multocida, which recurrently causes avian cholera outbreaks in endangered albatross and penguin species breeding on the island. 3. High proportions of seropositive and DNA-positive individuals for P. multocida indicated that skuas are highly exposed to the pathogen and may be able to transmit it. Movement tracking revealed that the foraging ranges of breeding skuas largely overlap among individuals and expand all along the coasts where albatrosses and penguins nest, but not on the inland plateau hosting the endemic Amsterdam albatross (Diomedea amsterdamensis). 4. Considering the epidemiological and movement data, skua movements may provide opportunity for pathogen spread among and within seabird colonies. 5. Synthesis and applications. This work highlights the importance of considering the behaviour and epidemiological status of predators and scavengers in disease dynamics because the foraging movements of individuals of such species can potentially limit the efficiency of local management measures in spatially-structured host communities. Such species could thus represent priority vaccination targets to implement efficient management measures aiming at limiting pathogen spread and also be used as sentinels to monitor pathogen circulation and evaluate the effectiveness of management measures.