Photographer Reveals What Whales Look Like When They Snooze

vertical sleep whales
Credits: Stephane Granzotto

It can be quite strange to see one of the largest marine animals taking a break from work.

Many photos of sperm whales in motion have been posted online. They are seen arranged vertically in the ocean. These whales are about the same size as school buses and appear almost always to be standing, clustered in pods of five to six.

Stephane Granzotto, a French filmmaker and photographer, captured the behavior while diving in the Mediterranean to document sperm whales. He was doing so for his Cachalots photo book. The photo above, which he submitted to National Geographic’s YourShot community, shows that the whales were asleep for about an hour.

In 2008, Current Biology published a study that documented the vertical sleeping position of the whale.

While some cetaceans were able to observe sleep by watching their eye movements, it was not possible to see how wild whales rest. Researchers from the University of St. Andrews used data-collecting tags to measure the animals’ periods of inactivity.

These vertical sleeping positions were discovered to be seven percent of their daily time. They slept for between 10 and 15 minutes. Scientists suggested that the whales might not be as sleep-dependent as other animals.

Scientists have found that whales kept in captivity use half of their brains while they sleep, which could be a sign that the animals are able to avoid predators, keep social contact and continue swimming.

Also, the study noted observations made in northern Chile from a video that showed whales didn’t wake up from their surface sleeps until a ship approaching with its engines unintentionally bumped into it. This indicates that whales in the wild may enter deep sleep, unlike their captive counterparts.

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