Swiss wild fauna lensman Franco Banfi too a squad of scuba divers were next a pod of sperm whales off the coast of Commonwealth of Dominica Island inwards the Caribbean Area Sea , when all of a abrupt the large creatures became motionless too savage into vertical slumber. This phenomenon was offset discovered alone inwards 2008 , when a squad of biologists from the United Kingdom of Great Britain too Northern Ireland too Nihon inadvertently drifted into a grouping of sperm whales floating merely below the surface , completely oblivious to their surrounding. It was alone when i of boats accidentally bumped into i of the whales , did the creature woke upward too the entire pod scurried off.
Until too thus it was idea that sperm whales , similar other toothed cetaceans , slept amongst i side of their encephalon turned on to create of import things that postulate physical action , such equally swimming or coming to the surface to breathe or avoid predators. It’s similar keeping i pump opened upward at all times , never fully letting their guard down.
The 2008 incident suggested that whales mightiness slumber amongst both sides of the encephalon turned off. The researchers also discovered that whales get got brusque , but periodic , bouts of slumber throughout the solar daytime amongst periods ranging betwixt vi too 24 minutes , but drift into deep slumber for alone most vii part of the time. These these brief naps mightiness hold upward the alone fourth dimension the whales slumber , which would brand sperm whales mayhap the to the lowest degree sleep-dependent mammals known to man.
Sources: Current Biology / Kottke / Gizmodo