Sperm Whales' Sleep Habits
Unlike humans, sperm whales have a unique way of sleeping. They rest vertically in the water, heads slightly tilted upwards, and remain motionless during this resting state.
Short Napping Sessions
Sperm whales do not sleep for long periods. Instead, they take short naps that can last between 6 to 24 minutes, occurring several times each day.
Sperm whales experience unihemispheric slow-wave sleep. This means they shut down only one half of their brain while the other half remains alert, helping them maintain basic life functions and awareness.
Group Sleep Formation
Occasionally, sperm whales sleep together in groups, forming a pattern resembling a synchronized, vertical raft. This collective behavior is not yet fully understood.
Sleeping without Breathing
During these rest periods, sperm whales don't breathe. They can hold their breath for about 90 minutes, which encompasses their entire nap time before resurfacing for air.
Vulnerable When Asleep
While in this state, sperm whales are more susceptible to threats. Their stillness and the close proximity of group sleep can make them easy targets for predators and human threats.
Impact of Human Activity
Noise pollution from ships and marine exploration can disrupt sperm whales' sleep patterns, contributing to stress and affecting their ability to rest effectively.