Whales just kinda lay there and don't move all that much unless some Japanese whalers come around, they like to relax and float. Then they yawn and get a mouthful of krill. That really packs on the tons.
Different biology. They're not fat all the time. When they're feeding in Arctic or Antarctic waters, they're building up fat reserves to fuel their long journeys to their tropical breeding grounds. During the journeys to and fro, and while in the tropics, they don't eat. They use up their fat reserves in travel, courtship, mating, giving and nursing their rapidly growing calves on high energy milk. The calves have to be strong enough to make their first journey to the polar zones - and they will keep drinking from their mothers throughout the trip. By the time the whales arrive back in their feeding zones, they are lean and exhausted.
This post was edited by inky at September 21, 2019 1:31 AM MDT
They're not. This is what they look like when they are in shape. There are NO fat whales. They are all buff. They are tight. They are toned. Even with all that "blubber".