Penguins
Stealthy survey shows penguins sleep more deeply in the afternoon
A French ecologist claims he's found the first evidence that wild birds have varying sleep patterns.
Gérard Dewasmes from the University of Picardy in Amiens made the observation after spending a month creeping up on Antarctic king penguins.
His painstaking research involved sneaking up to sleeping birds and tapping them on the shoulder at regular intervals with a weighted stick.
He found it took an average of nine pokes rouse a bird in the afternoon, four more than in the morning.
He says this shows the birds' sleeping patterns are synchronised with their surroundings.
He told Nature: "I think that breeding birds must adapt their sleep strategies to surrounding social activity."
He suggests the birds sleep less deeply in the morning because there tends to be more activity in the colony.
Birds tending chicks or eggs need to be more watchful because they are more likely to be jostled by neighbours.
He concludes that the relative inactivity of the afternoon lessens the need for vigilance, giving rise to deeper sleep.
Story filed: 10:52 Thursday 26th September 2002
Ananova 09/26/2002Categories: Clean, Animals, Silly, True Stories