Page last updated at 23:07 GMT, Tuesday, 13 May 2008 00:07 UK

Sloth's lazy image 'a myth'

By Helen Briggs
Science reporter, BBC News

Sleeping sloth (Image: Bryson Voirin)
The three-toed sloth is the slowest mammal in the world

The sloth's popular image as a lazy creature that sleeps for most of the day has been called into question.





They don't seem to sleep an inordinate amount of time
Dr Niels Rattenborg



The work, published in the Royal Society journal Biology Letters, attempts to find traits that predict whether an animal sleeps more or less than another species. This might provide clues to the function of sleep, said Dr Rattenborg.

He added: "I think this finding is really going to open the door to a whole new age of sleep research on animals sleeping in their natural habitat."

Proof of principle


Sleeping sloth (Image: Bryson Voirin)
They spend much of their time in trees


They caught three female brown-throated three-toed sloths living in rainforest near the Smithsonian Tropical Research Institute on Barro Colorado Island, Panama.

The animals were fitted with the data recorder and then released.

When re-captured several days later, measurements showed that they slept for an average of 9.6 hours a day, compared with a sleep time of 16 hours a day reported in sloths kept in captivity.



Despite many years of research into the function of sleep, there are still many unresolved questions.

It is known that sleep plays an important role in maintaining normal mental functions, but the precise mechanisms are unclear.

Scientists compile 'book of life'
09 May 07 |  Science/Nature


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