20 November 2022
Last week as I walked past a team of Allegheny Goatscape goats munching invasive plants in Schenley Park, I noticed a sign that described their sleep cycles. The goats, who are guarded by a donkey, sleep 5 hours in a 24-hour day. The donkey sleeps only 3 hours. Imagine being able to function normally on so little sleep!
Some animals sleep less than we do, some sleep more.
We humans, who average 8 hours per day, are well aware of our pets’ sleep cycles. Cats sleep 12 hours a day (so do mice!). When this man gets up his cat will curl up in the warm spot and go back to sleep.
Adopted greyhounds are champions at sleeping 18 hours a day.
Brown bats have one of the longest sleep cycles at almost 20 hours (19.9 hours per day according to this table).
Birds are in the middle, sleeping 10-12 hours a day, but their sleep is highly variable by species, place and season, especially in the Arctic where a summer “day” can be 24 hours long.
Guppies sleep slightly less than humans at 7 hours a day.
And giraffes win the prize for the least sleep at only 1.9 hours a day!
Did you get enough sleep last night? No? Then it’s time for a nap!
For more information see:
- Why do some animals need so little sleep? Science Magazine: Forty Winks in the Wild
- Table: How much do various animals sleep? from Prof Chudler at Univ of Washington
- Article on Sleep in Animals at Wikipedia.
(photos from Wikimedia Commons except where indicated; click on the captions to see the originals)