Getting some shut eye

Comparison of sleep patterns of selected mammals and birds

source: Emma Young
New Scientist vol 197 no 2647, March 15 2008
starts p 32, 2 pages long

Humans sleep relatively little, ranking fourth in a sample of 12 species of mammals and birds, behind giraffes, elephants and whales, while dogs rank sixth in this sample. Though dogs tend to sleep for longer overall, ten hours on average compared with eight for humans, humans have more REM or rapid eye movement sleep than dogs. Dogs clock up some nine hours non-REM sleep compared with humans at some six hours, so dogs have only around one hour of REM sleep compared with two for humans. Zebra finches, on the other hand, rank tenth overall, with over 14 hours total sleep and very little REM sleep, while lions rank ninth, with around 14 hours total sleep some some four hours REM sleep. The information in this article is presented in graphic form.