Watch rare footage of a blue whale feeding in the Pacific Ocean

Blue whales can grow up to about 30 metres long and weigh 140,000 kg. To maintain their bulk, they have to eat about 40 million krill a day. Whales only evolved such massive body sizes in the past few million years, a new study reveals.

Blue whales can grow up to about 30 metres long and weigh 140,000 kg. To maintain their bulk, they have to eat about 40 million krill a day. Whales only evolved such massive body sizes in the past few million years, a new study reveals.
READ MORE