Controlled sleeping

Birds can sleep with half thei (Credit: amit shanker / cse)BIRDS can sleep with one eye open and half of their brains awake. It is called Unithemispheric Slowave Sleep (usws). It allows birds to detect approaching predators while still getting a bit of sleep. "They are able to make behavioural decisions about whether to keep one half of the brain awake or allow both halves to sleep," said Niles Rattenborg, a neurophysiologist at
Indiana State University, USA.

He believes that the research is the first evidence of a species controlling sleep and wakefulness simultaneously. Dolphins and seals also have usws, which allows them to sleep and swim to the surface to breathe, but Rattenborg said birds seem to be able to use this at will. He added that they can also let both halves of the brain sleep. Under risky situations they increase the proportion of their sleep with one eye open and half their brain awake, said Rattenborg. He thinks the research could also have implications for humans.