Did you know that penguins can take more than 100 naps in a single day?
Hi, I’m Nate from polarguidebook.com, and in this video, we’ll look at some of the strange
sleeping habits of penguins. So let’s get started.
Penguins are neither nocturnal nor diurnal, they are cathemeral, which
means that they can be active at day or night. Essentially, they get their sleep whenever
they can, but it depends on many factors such as predators and food availability.
Remember, some penguin species inhabit Antarctica and sub-Antarctic islands which experience polar
nights and midnight sun seasons. This can result in days,
weeks, or months of total darkness followed by days, weeks, or months of total daylight. So
they must be able to survive in both. Penguins have some bizarre sleeping habits
that we might find unusual. Whereas humans can be classed
as monophasic sleepers, which means that we get most of our sleep in one block during the night,
penguins are polyphasic sleepers. This means that they get their sleep in many smaller blocks.
Add together cathemeral activity and a polyphasic sleep pattern, and you get
an animal that loves to nap. Most species never sleeping for longer than 10 minutes at a time.
They still get a good amount of sleep though. A study of Emperor Penguins in their natural habitat
found that they spend almost 11 hours sleeping during a 24 hour period.
During the study, the average length of each nap was between 4 to 7.5 minutes. When you do the
math, that’s more than 100 naps in a day. Whilst we might not be able to match this,
there is one thing we do have in common with penguins. This is that their post-lunch
afternoon nap is their best time to nap. This is likely due to less disturbance from
fellow penguins since they are less active in the afternoon than in the morning.
It’s not just the timing of the naps that are interesting, the location is surprising too.
Penguins can spend up to 75% of their daily lives in the ocean so they can nap in water or on land.
Whilst at sea, penguins can sleep by floating near the surface
since their excess fat makes them very buoyant. Whilst they are sleeping, the countershading of
their feathers provides camouflage to protect them from predators.
Check out the video in this card to learn more about the camouflage effect of a
penguins black and white color scheme. Whilst on land, penguins sleep standing up,
usually with their beak tucked behind one of their flippers.
By standing up, they minimize the amount of body contact with cold or hot surfaces
and can better regulate their temperature.
We should mention that Little Penguins are the exception to most things we’ve discussed today.
They are nocturnal whilst on land and tend to sleep in burrows during the day,
away from the intense heat of Australia and New Zealand where they live.
Penguins often sleep in groups for both warmth and protection from predators.
They use sight and sound to stay safe while they sleep.
By only resting half of their brain at a time, they leave the other half
alert to listen for the sound of incoming predators. This is known as uni-hemispheric
slow-wave sleep and is common among birds. Some species, such as the Humboldt Penguin, also
sleep with one eye open, allowing them to look out for approaching threats whilst they sleep.
It’s a technique known as unilateral eye closure and is also used by parrots and
ducks as well as some marine mammals such as whales and porpoises.
If you found these facts interesting, our next video has 12 more fun facts about penguins,
from their inability to taste meat despite being carnivores,
to penguin divorces that don’t always end amicably.
Hit the card to find out more. Thanks for watching.