Migratory behaviour of humpback whales in the southeastern Pacific under climate change.

Humpback whales, a species of baleen whale occurring in all oceans globally, undergo seasonal migration between their breeding grounds in tropical warm waters and high latitude feeding grounds. Using multiple years of satellite tracking data, we modeled the effect of oceanic conditions on the movement behaviour of 42 humpback whales belonging to the Southeastern Pacific population (also known as Breeding Stock G) during their migration from breeding grounds in Costa Rica, Panama and Ecuador to feeding grounds in waters around the Antarctic Peninsula. We report evidence that during their migration, humpback whales engage in a movement behaviour frequently associated with feeding, and that this behaviour was more likely to occur in relatively more productive waters. We show that whales partly rely on cues they perceive in their immediate environment to initiate their southward migration, but also on their memory of oceanic conditions on their feeding grounds, timing their arrival with the complete melting of sea ice which triggers a bloom of krill in the Antarctic Ocean. Overall, our findings suggest that humpback whales integrate information they gather from their immediate environment to predict the oceanic conditions at distant locations and adjust the timing of their migration, maximizing their interaction with their preys. However, it is unclear if humpback whales will fully succeed in tracking their preys in a rapidly changing climate and ensure the long-term persistence of the species.