Coastal winds are stronger and impact seabird behaviour and fitness in a warming Arctic

The Arctic is warming nearly four times faster than the rest of the planet. This unprecedented warming is profoundly altering environmental conditions. Coastal areas, which are crucial for biodiversity and human activities, are at the forefront of these changes. Among the major environmental changes expected in coastal regions are shifts in wind regimes and an increase in storm frequency. Using an interdisciplinary approach, we demonstrated that (1) wind conditions in Arctic coastal regions during summer are changing, resulting in a rise in strong wind events. (2) These large-scale changes in wind dynamics influence the movements and fitness of seabirds, with broader impacts on panarctic socio-ecosystems. To demonstrate these effects, we used a long-term study of little auks (Alle alle), the most abundant Arctic seabird species and an ecological indicator of Arctic coastal ecosystems. We showed that during strong wind events, little auks significantly reduce the visits to the colony. These behavioural changes negatively impact their fitness as inferred from chick growth rates. Overall, strong wind events disrupt the delicate balance between parental investment and self-maintenance in this long-lived species. Over time, such pressures may drive shifts in life-history traits, potentially affecting population dynamics.