2023-04-12 11:50:14
SKIMMING
ANIMAL DREAMS
SLEEP HABITS IN THE WILD
Almost all animals sleep, but how and how much they sleep varies from species to species. The little brown bat is one of the most prolific sleepers; it sleeps for around 20 hours per day. By contrast, giraffes sleep only 30 minutes per day in short bursts of five minutes each. And in general, herbivores sleep less than carnivores because they have to remain alert for predators.
Aquatic animals that breathe air experience difficulties sleeping because they have to keep swimming or they'll sink. Walruses respond to this with pharyngeal pouches, which are air pockets they can inflate to float while sleeping. Often, they'll also hook their tusks on ice foes to anchor themselves. Dolphins and whales solve this problem with hemispheric slow-wave sleep. This is the ability to sleep with only half of the brain, keeping the other half awake to drive motor functions.
Sleep studies are difficult because animals sleep more in captivity than in the wild. Sloths have a reputation for sleepiness, and indeed, they sleep around 14 hours per day in captivity. But wild sloths are much livelier, sleeping only around 9 hours per day.
Image credit: Joanna Turner/Unsplash
194 viewsMarkus Burns, 08:50
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