The Italian Almanac

dolphin and baby dolphin

Italian News - June 24

Baby dolphins sleep while swimming around, unlike their adult counterparts who have periods of stationary rest, a team of Italian researchers has found. The study, published in this week's issue of the international Nature magazine, followed months of observation and data collection by experts at the Genoa Aquarium in northwest Italy.

"During their first year of life, young bottlenose dolphins sleep exclusively while swimming and, like all young mammals, have irregular sleep patterns, distributed both through the day and at night, for around 12 hours in total," said the research team, Guido Gnone, Tiziana Moriconi and Giorgia Gambini.

"As they grow older, dolphins tend to reduce their hours of daytime sleep, while night sleep stabilizes at seven to eight hours. "This development in sleep patterns reflects that of land mammals, including that of human beings". The study overturns the findings of research published last year by US and Russian experts, which concluded that the constant movement of newborn dolphins and their mothers meant the mammals were barely sleeping.

The American and Russian teams reached their conclusions after observing that baby dolphins keep both eyes open and don't spend any time floating. But the Italian researchers suggest that rather than not sleeping, newborns and their mothers have developed alternative forms of rest. They remain in continual motion yet still spend much time asleep, possibly part of a survival technique to ensure they remain warm in cooler waters.