Southpaw sorrow for squirrels

IT is not just humans who are left or right-handed – it appears many squirrels also favour one paw or the other.

However, although this is believed to make human brains more efficient, it is not the case with squirrels.

Those who demonstrated a paw preference were actually found to be worse at learning new tasks than their ambidextrous counterparts.

Dr Lisa Leaver, of the University of Exeter’s animal behaviour course, said: “It has been suggested that being strongly lateralised makes brains more efficient.

“This could help animals survive, which would explain the evolution of laterality across the animal kingdom.

“In fish and birds, there is evidence that being strongly lateralised is linked to better cognitive performance.

“However, studies of mammals suggest a weak or even negative relationship.”

Researchers from Exeter observed 30 grey squirrels who were presented with a tube containing peanuts.

To access the nuts, the squirrels had to learn to use a paw, rather than their mouth.

Dr Leaver said: “We were measuring how long it took them to stop using their faces and to start using their paws to reach into the tube.

“Once they started doing that, we measured which paws they were using.”

While some squirrels used both paws to access the nuts, others strongly favoured one side or the other.

Results showed this second category of squirrels did less well on the learning task.

Dr Leaver said: “They didn’t learn as quickly and didn’t learn as thoroughly.”

The research was published in the journal Learning & Behaviour.