Bumblebees can teach themselves how to solve a puzzle box, and they prefer the method their sisters teach them to the ones they learn on their own. This adds to the evidence that these insects are capable of social learningand they use it to share trends and support cultures over time.
The researchers conducted a series of experiments in which 10 colonies of buff-tailed bumblebees (Bombus terrestris) had to solve a puzzle box to access a sugary solution inside. There were two possible solutions – pushing a red lever clockwise or pushing a blue lever counterclockwise. Each colony had a designated demonstrator bee who was privately taught one of two ways to open the box by a human trainer. Then the protesters were reintroduced to their settlements and the whole group had the opportunity, for 3 hours each day for 6-12 days, to crack the candy code.
THE the bees used the trick taught to them by their camp mates more than 98% of the time, even when more than half figured out that the other lever worked just as well. “Even when they found the easy alternative, they always returned to the demonstrated behavior,” explains Alice Bridges at Queen Mary University of London. “It was really crazy.”
In colonies where no bee was taught how to solve the puzzle by a human, the insects only managed to open the box a handful of times.
These results suggest that the behavior can spread in groups of bumblebees through social learning and being maintained over time, like cultural trends. “This is exactly what we mean when we talk about the transmission of culture in animal communities,” explains Andrew White at the University of St Andrews in the UK, which was not involved in the work.
These findings do an exceptional job of unveiling cultural learning in insects, says Claudio Tennie at the University of Tübingen in Germany. But this should be considered a “minimal” culture, he says, because it only tackles two areas of information.
In these experiments, the bees transmitted information in the “know what” domain – pushing the lever – and the “know where” domain – which lever. But they don’t necessarily share more complex information regarding “know-how,” like a series of multiple actions to perform with the lever, Tennie explains. “They land and, like a ram, they just push off,” he says. “I call these things minimal culture.”
Even a form of minimal social learning could be useful as a buffer against global warming or other common challenges. “Instead of waiting for the less equipped individuals to die from natural selection and the better ones to survive, if you can learn a new behavior to overcome a problem, it will really benefit you,” Bridges says.