Responses of Arctic marine birds to environmental constraints in the context of climate change

It is essential to reach a better understanding of ecological processes in the Arctic, as this ecoregion is hit severely by the consequences of global change. In this context, we study the ecophysiology of little auks (Alle alle), which are the most abundant seabirds of the Arctic, and acknowledged ecological indicators of changing marine ecosystems in this polar region. Via a unique long-term study of little auks breeding in East Greenland (Liverpool Land), in place since 2005, but also through specific experimental and modelling approaches, as well as through a panarctic network of collaborations, we propose to test the following hypotheses: (1) breaking points in the ecophysiological plasticity of little auks buffering the effects of multiple stressors during their breeding season will be reached linked to Arctic environmental change (2) Ongoing Arctic global change impacts the migratory ecology and winter ecophysiology of little auks in the North Atlantic through bird fidelity to wintering grounds independent of shifting environmental conditions. (3) Contaminants and other environmental stressors interactively impact the behaviour and reproduction of breeding little auks, with the intestinal microbiota acting as a modulator of these effects. (4) Long-term changes in pollutant concentrations over the last millennia, alone or in combination with changes in environmental conditions, are related to changes in little auk population sizes. All of our work participates in the Circumpolar Biodiversity Monitoring Programme (CBMP) of the working group Conservation of Arctic Flora and Fauna (CAFF) of the Arctic Council, and therefore corresponds to the expectations of Arctic peoples in terms of environmental research.