Abstract: Seabirds are well known to be hosts of a diverse set of parasites and pathogens. Most seabird species are also widely distributed, migratory, long-lived, colonial and site faithful. Such characteristics mean seabirds are potentially important model systems for investigating host-parasite interactions at a hierarchy of temporal and spatial scales. Key issues regarding the ecology and evolution of these interactions notably concern factors affecting dispersal of hosts and parasites among colony patches, but also local interactions between individual hosts and parasites, which can involve the transgenerational transfer of immunity through the egg. Using studies conducted with kittiwakes and the tick Ixodes uriae, but also other seabird species, notably the Indian yellow-nosed albatross and sub-Antarctic skua, I will illustrate how important of basic and applied questions can be addressed using such systems, with implication from comparative immunology to conservation.

Abstract: Infectious Diseases Threaten Wild Animal Populations, Notably Seabirds. Identifying The Different Components Of A Reservoir Community Is Key To Understand The Circulation Of Infectious Agents. Predating And/or Scavenging Birds Such As Skuas Have The Potential To Act As Epidemiological Bridges, Enhancing The Circulation Of Infectious Agents Among Other Seabird Colonies And Mammal Populations. On Amsterdam Island (Indian Ocean), Avian Cholera Is Causing Recurrent Die-offs Of Albatross And Penguin Nestlings. We Combine Movement Ecology With Eco-epidemiology To Assess Whether Brown Skuas In This System Could Represent Bridges Among Seabirds (Albatrosses, Penguins) And Mammals (Rats, Seals). We Notably Consider Behavioural Processes Potentially Involved In The Circulation Of Infectious Agents, Such As Foraging Territoriality. The Results Suggest That, At The Height Of The Epizootics, Skua Movements Do Not Connect The Endemic Amsterdam Albatross Population To The Local Epidemiological Network, Contrary To The Other Local Colonial Species. Additionally, This Study Illustrates How Predator And/or Scavenger Species Can Be Used As Sentinels To Detect Infectious Agents In Wild Settings. These Results Have Important Implications Regarding Our Understanding Of Infectious Agent Circulation At An Inter-specific Level And Potential Applications In Conservation Considering The Impact Of Avian Cholera On Seabird Populations.