DOMINICA, Caribbean Underwater footage making the rounds this week shows sperm whales doing something almost no other animal does: sleeping standing up. The clip captures a pod of the giants hanging motionless in the water column, heads up, tails down, drifting in tight formation just below the surface.
The posture is called drift-diving, and the first study to document it was published in Current Biology in 2008. Researchers from the University of St Andrews and the University of Tokyo suction-cup tagged 59 sperm whales worldwide and found 31 of them conducting passive, shallow drift-dives in stereotypical vertical postures just below the surface, the university’s research release states.
Those naps are short. The whales rested in this posture for about 10 to 15 minutes at a time without moving or breathing, spending roughly 7 percent of their day asleep, less than any other mammal studied, Live Science reported. A boat that drifted into a pod off Chile found the animals unresponsive until it touched one, which snapped them all awake.
How they stay put is its own discovery. Research published July 23 in the Journal of Experimental Biology, from the University of St Andrews and the Université de Neuchâtel, found the whales release gas bubbles while resting to offset their natural positive buoyancy, which comes from the spermaceti oil in their heads, and hold position just beneath the surface, Oceanographic Magazine reported. Sperm whales are the only whale known to rest vertically.
“This study confirms that sperm whales exquisitely control their buoyancy by releasing gases to remain submerged with near-neutral buoyancy just below the sea surface,” Patrick Miller, a professor at the Sea Mammal Research Unit at the University of St Andrews, said in a statement. “It is particularly fascinating that they are able to make these fine-scale adjustments while they are thought to be asleep, a challenge totally alien to terrestrial mammals like us humans.”
The vertical habit is exclusive. Sperm whales are the only whales known to rest vertically, in pods of five or six that photographer Franco Banfi documented off Dominica at a depth of around 65 feet, Live Science reported of the encounter. Most whales, like most mammals, sleep horizontally.
A Tuesday post sharing the sleeping footage has drawn more than 400 likes. The clip joins a long line of ocean moments that stop the scroll, and the whales were in no hurry to end theirs.
The ocean keeps producing such scenes. Hypefresh has covered the Great Pacific Garbage Patch becoming home to dozens of marine species, a jellyfish swarm halting a French nuclear plant, and Boosie catching a shark in his lake.
For the whales, the upright nap works because nothing bothers them while they hang there. For everyone watching, the appeal is simpler: school-bus-sized animals standing upright in the open ocean, asleep, and the new clip is the latest reminder that the deep still has footage left to surprise.
