When honey bees return to their hive after foraging, they show their nest mates the way to promising food sources using the waggle dance. But as a study now shows, the bees change their dance depending on who is watching them: While they carry out precise movements when there is a large audience of other foragers, they become more careless when there are only a few other bees present or when the audience is mainly made up of young bees that are not looking for food themselves. The waggle dance is therefore not a one-way transfer of information, but rather a communication process in both directions.
Honey bees use the waggle dance to encode complex directions. Once a scout returns to the hive after discovering a good food source, she begins her dance. She quickly crawls straight ahead for a few centimeters with her abdomen wobbling, then returns in an arc to the starting point, repeats the performance and returns again in the opposite direction. This creates a figure eight pattern with a meandering center line. The angle of the center line conveys the direction of the food source in relation to the sun, and the duration of the performance provides information about the distance of the food source. Other collectors watch the dancer, touch her with their antennae and then make their own way to the location described.
Better dancing in front of a bigger audience
“The honey bee’s waggle dance is often viewed as a one-way transfer of information from the dancers to the signal receivers,” explains a team led by Tao Lin from the Chinese Academy of Sciences in Yunnan. But as new studies by the researchers show, this assumption is not correct. For their study, they changed the number and composition of spectators in a test beehive. “Our data shows that audience feedback shapes the signal itself,” reports Lin’s colleague Ken Tan. “In this sense, the dancer not only sends information, but also reacts to the social conditions on the dance floor.”
If many other foragers were present as spectators, the dancer performed precise movements that precisely encoded the location of the food. With a smaller audience, however, the dancers made larger movements – possibly to attract more nest mates’ attention. However, they neglected precision. “It’s not just people who behave differently depending on the audience,” says co-author Lars Chittka from Queen Mary University in London. “Our study shows that honey bees literally dance better when they know someone is watching. When there are few spectators, the dancers wander around looking for an audience – and their signals become fuzzier.”
Coordinated notes
But apparently it is not just the number of spectators that shapes the scout’s dancing behavior. The qualifications of the observers also play a role. If the researchers put young bees in the audience that don’t go looking for food themselves, they obviously didn’t count for the dancer. “Even when the dance floor was crowded with young bees not following the dances, the dancers showed the same loss of precision,” the team reports. So it’s not just a matter of how many are watching, but also who is watching. The dancer probably obtains information about her audience through antenna and physical contact with onlooking collectors. These tactile cues not only allow the observer to better process the dance, but also the dancer to adapt her performance.
The results may also be applicable to other collective species and could potentially improve the performance of autonomous, collaborative robots. “The new findings show that the accuracy of a signal can depend on the availability of receivers, not just on the motivation of the sender,” says Chittka’s colleague James Nieh. “This type of feedback could be important in animal societies, artificially created swarms, and other distributed systems where the quality of information can rise or fall with audience dynamics.”
Source: Tao Lin (Chinese Academy of Sciences, Yunnan, China) et al., Proceedings of the National Academy of Sciences, doi: 10.1073/pnas.2518687123