They just act stoned.
As Dean Wormer would tell you, “Fat, drunk, and stupid is no way to go through life.” We can rule out that manatees are drunk — although alcohol run off from Panama City Beach may bump the Gulf of Mexico up to 10 proof, that’s hardly enough liquor to get a half ton beast hammered. But they’re definitely fat and appear quite stupid.
Research out of the Mote Marine Lab indicates that we shouldn’t mistake the manatees’ half-baked attitude for stupidity. These marine mammals aren’t stupid; they’re just happy. And lazy. And fat. But they ain’t dumb:
Hugh, a manatee in a tank at a Florida marine laboratory, doesn’t seem like a dimwit. When a buzzer sounds, the speed bump-shaped mammal slowly flips his 1,300 pounds and aims a whiskered snout toward one of eight loudspeakers lowered into the water. Nosing the correct speaker earns him treats.
These behemoths only seem dumb because they have no natural predators (aside from a 50 horse power Yamaha). Without predators, there’s been no selection pressure for quickness and agility. That’s allowed them to evolve into fat-asses that appear to be dumb as bricks.