Scientists studying wild vervet monkeys in South Africa found that the animals were better able to learn a task when it was demonstrated by a female.

The team compared animals' responses to demonstrations of a simple box-opening task, which was demonstrated either by a dominant male or female monkey.

Their findings are described in the journal Proceedings of the Royal Society B.

Biologist Erica van de Waal, from the University of Neuchatel in Switzerland, and her team, studied six neighbouring groups of wild vervet monkeys in South Africa's Loskop Dam Nature Reserve.

They gave the monkeys boxes containing fruit, which had doors on each differently coloured end.

During an initial demonstration, the researchers blocked one of the doors, so there was only one correct way to solve the box-opening puzzle and access the fruit reward.

For three of the groups, a dominant male monkey was selected as a "model" to demonstrate the task and for the other three a dominant female was chosen.

"The models learned by trial and error how to open the box," explained Ms van de Waal. "Once they understood how to pull or slide the door open we let them perform 25 demonstrations."

After this "demonstration phase", the other monkeys were far more likely to try - and to succeed in - opening the fruit box if their demonstrator was a female.

"We found that bystanders paid significantly more attention to female than male models," said Ms van de Waal.

"[This] seemed to be the only factor influencing this social learning."