“The Power of Imitation: Capuchin Monkeys Discover Efficient Fruit Consumption through Peer Observation”

Capuchin monkeys learn the most efficient way to open fruit based on the method with the highest payoff, researchers have found.

They monkeys used a mixture of learning by observation and individual experience to use their canines to open fruit from Panama trees – which are lined on the inside with stinging hairs.

This type of payoff based learning could be used by animals to adapt to rapidly changing conditions, for example due to climate change.

The study, conducted by researchers at the University of California, Davis, found that while wild capuchin monkeys readily learn skills from each other, that social learning is driven by the payoff of learning a new, useful skill.

According to the researchers, it’s the first demonstration of ‘payoff bias’ learning in a wild animal – and it could inform researchers as to whether and how animals can adapt to conditions of rapid change such as climate change or the reintroduction of new species from captive breeding.

‘What are the psychological mechanisms animals use to learn?’

To help answer these questions, Barrett studied a population of capuchin monkeys in Lomas de Barbudal Biological Reserve, northwest Costa Rica that was part of a 27-year study by UCLA evolutionary anthropologist professor Dr Susan Perry.

Barrett says that capuchin monkeys are interesting because they have sophisticated social behaviors, and the relationships they develop with each others are known.

‘They explore their world, harvesting food from it,’ Barrett said.

‘That includes coming up with new ways to open and harvest hard-to-access fruits and seeds.

‘Unusually for monkeys, capuchins will tolerate other monkeys watching them as they open fruit.’

Barrett and other researchers studied learning strategies in the monkeys by observing how they learned to open fruit of the Panama tree.

The edible nuts inside the large fruit are well-protected by a hard shell covered in gooey exudate and lined on the inside with stinging hairs.

Usually, a group of monkeys familiar with the fruit will have worked out their own way to open them, making it hard to figure out how monkeys learned the technique.

Instead, the researchers were lucky enough to find a group of monkeys that had split off from a larger group in 2003, and moved to an area that had no Panama trees.

While some of the older animals had experience with different ways of opening the fruit, others had no experience at all.

After observing this group, the researchers found that, overall, most monkeys adopted the most efficient technique for opening the fruit – the method with the highest payoff.

While some of the older animals had experience with different ways of opening the fruit, others had no experience at all.

After observing this group, the researchers found that, overall, most monkeys adopted the most efficient technique for opening the fruit – the method with the highest payoff.

‘We found that the most efficient technique could spread very quickly through the group, in as little as two weeks,’ said Barrett.

Even older monkeys that had already mastered one opening technique would pick up another that was more efficient by watching others,’ Barrett said.

The researchers found that monkeys used a mix of learning by observation and individual experience to figure out how to open the fruit.

While older monkeys tended to rely on their own experience, younger ones paid more attention to how other animals opened the fruit.

Some of the monkeys settled on their own technique, even if it wasn’t as efficient – but they were still guided through different options by watching other monkeys.

The study shows that ‘payoff-bias’ learning – guided by which technique is more efficient – may be more widespread in wild animals than previously thought.

Understanding how animals learn skills could be important, for example, when considering how to reintroduce captive-bred animals to the wild, or moving a population into a new habitat.