Reindeer slept roughly the identical quantity throughout winter, summer time, and autumn, although they had been far more lively throughout the summer time. File.
| Photo Credit: AP
Researchers have found that the extra time reindeer spend ruminating, the much less time they spend in non-rapid eye motion (non-REM) sleep. EEG recordings revealed that reindeer’s brainwaves throughout rumination resemble the mind waves current throughout non-REM sleep, and these brainwave patterns recommend that the reindeer are extra “rested” after ruminating. The researchers speculate that this multitasking would possibly assist reindeer get sufficient sleep throughout the summer time months, when meals is plentiful and reindeer feed nearly 24/7. The outcomes had been printed on December 22 within the journal Current Biology.
Light-dark cycles are absent within the Arctic throughout winter and summer time, and earlier research confirmed that Arctic-dwelling reindeer don’t show circadian behavioural rhythms throughout these seasons, although they are usually extra lively throughout the daytime throughout the spring and autumn equinox, when light-dark cycles are current.
They discovered that reindeer slept roughly the identical quantity throughout winter, summer time, and autumn, although they had been far more lively throughout the summer time. This is in distinction to different species who change the quantity they sleep in response to environmental situations. On common, the reindeer spent 5.4 hours in non-REM sleep, 0.9 hours in REM sleep, and 2.9 hours ruminating throughout a given 24-hour interval, no matter season.
One doable technique is the chance for relaxation throughout rumination — the re-chewing of partially digested meals, which is a vital part of digestion for reindeer and different ruminants. Domestic sheep, goats, cattle, and lesser mouse-deer have all been beforehand noticed to supply sleep-like mind waves throughout rumination, but it surely was unclear whether or not rumination may serve the same restorative perform to sleep.
The reindeer’s EEG readings throughout rumination resembled brainwave patterns which are indicative of non-REM sleep together with elevated slow-wave exercise and sleep spindles. Sleeping and ruminating reindeer additionally displayed related behaviour, tending to quietly sit or stand throughout each actions, and had been much less reactive to disturbances similar to a neighbouring reindeer sitting down or getting up.
Next, the researchers examined whether or not rumination may cut back the reindeer’s drive to sleep by depriving the reindeer of sleep for 2 hours. Following sleep deprivation, the reindeer’s EEG readings indicated a build-up of ‘sleep pressure’— the unconscious organic drive for extra and deeper sleep — suggesting that reindeer expertise deeper sleep following sleep deprivation.
