Reindeer can chew their food and sleep at the same time

Reindeer seem to snooze all through the day whereas chewing their cud. This can be an adaptation to their Arctic habitat, the place meals is considerable in the summertime they usually should continuously eat to realize sufficient weight to outlive the winter.

To assist break down the fibrous vegetation that make up their weight loss program, reindeer ruminate – that’s, they regurgitate meals from their abdomen again into their mouth for additional chewing. And so they usually tackle a trance-like stare as they chomp. “You may type of see it of their face, they’re a bit gone,” says Gabriela Wagner on the Norwegian Institute of Bioeconomy Analysis. “However no one knew in the event that they have been truly asleep as a result of nobody has ever measured the brainwaves of reindeer earlier than.”

Wagner and her colleagues used an electroencephalograph (EEG) – steel electrodes hooked up to the heads of 4 captive Eurasian tundra reindeer (Rangifer tarandus tarandus), which recorded electrical pulses of their brains over the subsequent few days as they ate, slept and moved round.

The reindeer’s brainwave patterns revealed that, when ruminating, they have been in a light-weight stage of sleep generally known as non-REM sleep, suggesting the animals can recharge whereas chewing their cud. “It seems very very similar to human sleep – it’s received the identical levels of sleep spindles and gradual wave exercise,” says Wagner, describing bursts of mind exercise seen on the EEG. In addition they discovered that the extra time the reindeer spent ruminating, the much less they wanted extra relaxation.

Wagner suspects this sort of multitasking would possibly assist the animals get sufficient relaxation throughout the summer time after they spend nearly all their time feeding in preparation for winter. “This appears to be an ideal adaptation to the Arctic, the place you simply have a really quick interval of the 12 months when you need to eat on a regular basis to get fats,” she says.

Resting whereas ruminating may additionally clarify why, in contrast to most different species that sleep extra in winter, reindeer seem to sleep the identical quantity whatever the season.