US researchers have managed to capture the world's largest sea creature feasting on their only type of prey off New Zealand's coast.
Oregon State University researchers captured the video of a rare Antarctic blue whale turning on its side to lunge and feed on a large group of krill.
Researchers were able to conclude that the whales make calculated decisions over whether to expend energy lunging for the krill after comparing the drone footage to previous vision where a whale swam right past a school of krill.
Footage of blue whales feeding is incredibly rare, according to the university's Marine Mammal Institute principal investigator Leigh Torres.
She told Radio NZ that the lunge required the whales to dramatically slow down and the energy required to speed up again could be more than the energy they would get from eating a smaller group of krill.
"The whale determined that amount of krill to be gained and the effort it would take to consume the meal wasn't worth the effort of slowing down," Ms Torres said.
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Blue whales are the size of approximately three buses.
The NZ Department of Conservation said commercial whaling in the 20th century severely affected blue whale numbers and they have dropped from approximately 200,000 to less than 2000.