Migration is energetic

 

A great study, showing what drones can do for science, analyzed how much body fat humpback whales lose while migrating. It's a lot.

They followed the whales with drones to determine their volume change, which is impressive in itself.

Humpback Whales Lose 36% Body Fat During Migration

"Mr Bernier-Graveline and the research team used data from the drone monitoring to determine the whales’ body conditions on their breeding ground in Colombia and on their feeding ground on the Western Antarctic Peninsula, a highly productive krill region of Antarctica.

Each adult whale lost about 36 per cent of its body condition during migration which is equivalent to:
- 12 cubic metres or 11,000kg of blubber (equivalent to the weight of a standard single-decker city bus or two adult African elephants)
- 5,000kg of fat
-196 million kilojoules of energy (equivalent to the energy consumed by an average adult over 62 years)
- 57,000kg of krill

This should clearly illustrate the importance of maintaining the Southern Ocean ecosystem in a productive state that keeps the krill stocks big and thick.

Reference: Bernier-Graveline A, Nash SB, Bierlich KC, et al. Drone-based photogrammetry provides estimates of the energetic cost of migration for humpback whales between Antarctica and Colombia. Mar Mamm Sci. 2025. doi: 10.1111/mms.70048