Bees move to communicate. But to do it well, they need dance lessons

In a castaway test setup, groups of young bees figure out how to feed themselves and start dancing spontaneously — but poorly.

The fuss matters. A bee’s rump strokes and spinning loops encode cues that help its colony mates fly to the food it has found, sometimes miles away. However, five colonies in the new test did not have older sisters or half-sisters as role models for successful dance moves.

Still, the dances improved in some ways as the youngsters squirmed and twirled day after day, reports behavioral ecologist James Nieh of the University of California, San Diego. But waving the clues to get distance information, Apis mellifera without role models, the timing and coding never matched normal colonies where young bees practiced with older foragers before doing the main movement themselves.

The colonies reserved for young people thus show that social learning, or lack thereof, is important for communicating through dance among bees, Nieh and an international team of colleagues say in the March 10 Science. The dance of bees, a kind of language, turns out to be both innate and learned, like the songbird or human communication.

The dance may look simple in a diagram, but performing it on honeycomb cell spans becomes difficult. The bees “run forward at more than one body length per second in pitch black trying to keep the right angle, surrounded by hundreds of bees hurrying them,” says Nieh.

Beekeepers and biologists know that certain types of bees can learn from others of their species – some bumblebees even tried football (SN: 02/23/17). But when it comes to the fidgeting dance, “I think people assumed it was genetic,” Nieh says. It would make that whimsical footwork look like the talkative but innate communications of the color-changing cuttlefish, for example. Instead, lab experiments on shipwrecked bees show a non-human example of “social learning for sophisticated communication,” says Nieh.

Social learning tests required elaborate beekeeping. At a beekeeping research center in Kunming, China, researchers placed thousands of near-adult bees (in the purple-eyed pupal stage) in incubators, then collected the brand new winged adults as they emerged. .

These youngsters went to five colonies strangely populated by beginners of the same age. Each colony had a queen, who laid eggs but did not leave the colony to feed. The food had to come from the young workforce, without older, experienced pickers buzzing and dancing about the flower pitches.

In the wriggling dance, the foraging bees must master not only the movements but also the obstacles of the honeycomb dance floor. A cell can be empty. “It’s just the edges to cling to…. It would be easy to stumble,” says Nieh. Unlike commercial hives with fabricated uniform honeycomb cells, natural combs “are very irregular,” he says. “Along the edges they get a little crazy and rough.”

The dances on these treacherous surfaces encode the direction of the food in the angle a dancer wiggles on the comb (measured against gravity). The duration of the choppy fight gives a clue as to how far away the bonanza is.

The five colonies of castaways had to fend for themselves to dance, unlike five other colonies in the apiary with a natural mixture. At the start of the experiments, the researchers recorded and analyzed the first dances of five bees from each hive.

Even in the mixed hives, the dancers weren’t getting the perfect angle every time. The extremes of a choppy six-race set can differ by a little more than 30 degrees. Castaway hives, however, had a lot more problems at first. Two of the castaway dancers’ five angles deviated more than 50 degrees, and one poor bee deviated more than 60 degrees in six repetitions.

As the castaways gained experience, they improved. Repeating the test with the same tagged bees a few weeks later near the end of their lives found them to line just as well as dancers in a normal hive.

What Castaways haven’t changed much are the dance characteristics that encode distance to food. The researchers had set up the hives so that everyone had the same experience of flying to a feeder. Yet the shipwrecked bees persisted in dancing as if it were further away.

They gave more rump wiggles per wiggle run (closer to five wiggles) than bees from mixed-age hives (more like 3.5 wiggles). The youngsters also took longer in each race.

Evidence like this foraging study “is indeed accumulating on the importance of learning (individual or social) in the complex behaviors of bees,” said insect ecophysiologist Tamar Keasar of the University of Haifa in Israel in an email. In her own work, she sees bees learning to extract food from intricate flowers. Bees are not, after all, little automatons with wings.