How does a killer whale sleep?

Dolphins and beluga whales sleep by shutting down one hemisphere of their brain at a time. Because killer whales are physiologically similar to these species, it’s thought that they sleep in the same way. While half of the killer whale’s brain catches up on sleep, the other half controls the breathing. read more

Killer whales (Orcinus orca) can only breathe voluntarily, which means they will drown if they fall completely asleep in the same way as people. Killer whales are also called "orcas" and belong to a family called cetaceans, which includes animals such as dolphins and Beluga whales. read more

Killer whales do sleep with their eyes closed, just like people. However, newborn killer whales do not sleep at all. When a female orca has a baby, she may go weeks without any sleep. read more