Otters juggle with stones as a sign they are hungry

Otters are regularly seen using their little hands to juggle small rocks and this bizarre behaviour may be because they’re hungry, a new study claims.

Otter juggling has never been fully understood, with previous research saying it may be useful in improving their foraging skills. 

But scientists have now discovered that when it is dinner time, otters often juggle as they wait for their food.    

Researchers are still not convinced of rock juggling’s exact purpose but say there is definitely a link between hunger levels and the circus act. 

Whether rock juggling is beneficial or a random hobby is yet to be determined. 

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Otters are regularly seen using their little hands to juggle small rocks and this bizarre behaviour may finally be understood, thanks to a new study. Pictured, two attentive Oriental small-clawed otters with one juggling a stone

The dextrous mammals are often seen lying on their backs and batting the stones into the air, catching them and rolling them around their chests and necks. 

Scientists from the University of Exeter who conducted the study believe this behaviour might help juvenile otters develop their motor skills.

They found that young and elder otters juggled more than adults, but otter species and sex didn’t impact on juggling behaviour.

For the long-in-the-tooth otters, experts suggest juggling rocks could be a way to pass the time and keep their brains active, similar to humans doing puzzles to keep their minds engaged as they age.

However, the key driver for the behaviour is likely hunger, according to the study published today in the journal Royal Society Open Science .

Mari-Lisa Allison, of the University of Exeter and lead author of the study, says the ultimate function of the behaviour is still a mystery.

She said: ‘Our strongest finding is that otters juggled more frequently before being fed, indicating that the immediate driver of the behaviour is hunger.

‘More research is needed to investigate the ultimate function of the behaviour.’

Pictured, a young otter juggling with a pebble. Scientists found that young and elder otters juggled more than adults, but otter species and sex didn’t impact on juggling behaviour