Reindeer are able to eat and sleep simultaneously

The reindeer seems to be dozing all day long, ruminating on the cud. This may be an adaptation to their arctic habitat, where food is plentiful in the summer and they must eat constantly to gain enough weight to survive the winter.

Reindeer chew the cud to help break down the fibrous plants that make up their food. That is, it regurgitates food from the stomach back into the mouth for further chewing. And they often stare at each other in a trance-like manner while munching. “You can see it in their faces. They’re a little distant,” he says. gabriella wagner At the Norwegian Institute of Bioeconomy. “However, no one had ever measured reindeer’s brain waves before, so no one knew whether reindeer really slept.”

Wagner and her colleagues used electroencephalography (EEG) with metal electrodes attached to the heads of four Eurasian tundra reindeer.Langifer Tarandus Tarandus), and over the next few days recorded electrical pulses in their brains as they ate, slept and moved around.

The reindeer’s brain wave patterns revealed that when they ruminate, they are in a light sleep stage called non-REM sleep, suggesting that reindeer can recharge while ruminating. “It’s very similar to human sleep; it has the same stages of sleep spindles and slow-wave activity,” Wagner explains of the bursts of brain activity visible on the EEG. They also found that the longer reindeer ruminated, the less they needed additional rest.

Wagner suspects this kind of multitasking might help animals get enough rest during the summer, when they spend almost all their time foraging in preparation for winter. “This seems to be a perfect adaptation to the Arctic, where there is a very short period of the year where they have to eat all the time to gain weight,” she says.

Resting while ruminating may also explain why reindeer appear to sleep the same amount regardless of season, unlike most other species that sleep more in winter.