Washington, March 4 : German researchers have found that birds compensate for sleep loss in the same manner as humans, i.e. by "power napping".
Dolores Martinez-Gonzalez of the Max Planck Institute for Ornithology in Seewiesen says that just like humans and other mammals, birds also recover from periods of sleep loss by sleeping more intensely at a later time.
In humans, it is described as a deep, dreamless slow-wave-sleep (SWS). It has been so named because slow oscillations of neurons are reflected in the EEG (Electroencephalogram), as large slow-waves with a frequency of less than 4 Hz, during this pattern of sleep.
Scientists have known it for a long time now that the amount of slow-waves is positively correlated with the depth of sleep.
Although birds also show SWS, it remained unclear until recently whether they show the same response to sleep loss as humans and other mammals.
To find an answer to that query, the research team prevented pigeons from taking naps, something they generally do during the last hours of a day. During the night, the birds were allowed to sleep normally.
Although the time spent in SWS did not increase during recovery, the amount of slow-waves did increase, suggesting that pigeons and presumably other birds have the capacity to recover lost sleep without having to spend more time sleeping.
"If pigeons lose sleep when a predator is around, they can recover this lost sleep at a later time by sleeping more deeply. This intensity dimension to avian and mammalian sleep may give animals a certain degree of flexibility in how they acquire their daily sleep requirement", says Niels Rattenborg, co-author of the study and head of the research group Sleep and flight in birds at the Institute.
Based on their observations, the researchers came to the conclusion that the way sleep is regulated in birds and mammals seems to be more similar than previously thought.
They believe that this finding increases the chances of learning more about the function of sleep in humans by studying sleep in birds.
The study has been reported in the online edition of Journal of Sleep Research.