Future climate changes are expected to be associated with an increase in the strength of these extreme climatic events 4, 11. Over the past decades, the zone of cyclone occurrence has been shown to move poleward 9, and the strength of cyclones has increased 10. Tropical cyclones are extreme climatic events that are well known for their devastating effects on terrestrial and marine ecosystems 7, 8. Extreme climatic events are predicted to increase in frequency under climate change 4 and can have important negative effects on the dynamics of populations 5, 6. Adopting optimal movement decisions to avoid adverse conditions will be fundamental in the context of climate change 2, 3. Movement decisions are therefore a critical determinant of individual fitness and are likely a trait under strong selection 1. We discuss the potential consequences of an increase in cyclonic conditions on seabird populations.ĭuring their lifetimes, animals move in time and space to forage for food, find mates, and avoid adverse conditions or predation. These movements likely reduce the mortality risk at sea but can temporarily cause birds to move outside their normal range at sea or over land masses. Frigatebirds climb to high altitudes when close to the eye of the cyclone to bypass it at high speeds. When encountering at-sea gale conditions, adult birds were able to avoid the centre of the low pressure systems and moved westward to bypass the route of the cyclones and circumvent the moving cyclone. The mortality of the individuals remaining on land remained limited. When the winds reached gale force, the juveniles of both species and adult frigatebirds remained at the colony, whereas adult boobies continued their foraging routine. We show that when a cyclone approached, juveniles and adults of the two species differed in their decisions to leave the colony for the sea. We examined whether adults and young naïve birds were able to predict the arrival of a cyclone and behave accordingly to reduce mortality risks and optimise foraging. During the course of a study on the foraging behaviour of two tropical seabirds, red-footed boobies and great frigatebirds, several cyclones have affected their breeding grounds and foraging zones, allowing us to study their response to extreme wind conditions. In the context of climate change, how extreme climatic events, such as cyclones, will affect the foraging abilities of marine vertebrates is still poorly known.

Bird in a gale