Editor's Summary

22 June 2006

Asleep afloat

Mammals generally need more rest or sleep in the period just after birth than later in life. So a report in Nature a year ago raised eyebrows: killer-whale and bottlenose-dolphin neonates and their mothers showed little or no typical sleep behaviour for the first postpartum month, remaining mobile for 24 hours a day. This work suggested that sleep behaviour may not have the suspected developmental and life-sustaining functions, and has given rise to an interesting online discussion. Two teams raise the issue of sleep-like behaviour that may complicate matters, though definitions aside, these young mammals do seem to be remarkably active for extended periods.

Brief CommunicationsSleep behaviour: Sleep in continuously active dolphins

Yuske Sekiguchi, Kazutoshi Arai and Shiro Kohshima