Why do the whales migrate?
Humpback whales feed on krill which is abundant in the cold polar waters however they are unable to give birth in these rich feeding grounds because their calves are born without a protective blubber layer under their skin and would freeze to death in theses chilly waters. Because of this each year the humpback whales migrate to subtropical waters to mate and give birth.
The annual journey is one of the longest migratory journeys of any mammal on earth during which they do not eat, instead subsisting on their fat stores, known as blubber.
The timing of the migration varies each year depending on the location of they’re feeding ground, water temperature, sea ice, predator risk and abundance of prey. The humpback whales that migrate up the Australian east coast generally head north between June and August and head back south between September and November.