Marine biologists tracking cetaceans above the tree line are seen releasing puffs of air in order to stay afloat while sleeping upright in the water.
Tagged animals included nearly four dozen animals to record resting patterns in the wild in open water.
New findings suggest the whales' large heads appear not to cause tipping or wobble while at rest.
Several of the cows have been seen floating upside down off the bottom of the ocean as a recovery method to save strength.
That posture could offer support to nursing mothers while away from the group, members of the team point out.
That noted adjustment may expand461 research on animal rest, scientists add.