For bees and other social insects, the ability to exchange information is critical to the success of their colony. Honey bees achieve this through their agitated dance, which is a unique behavioral model that probably evolved more than 20 million years ago. A bee dance of a bee tells her colony sisters where to find a high quality food source. However, in recent years, people have begun to study the real benefits of this dance language. Biologists from the University of Lausanne in Switzerland and the Johannes Gutenberg University of Mainz (JGU) in Germany have now shed new light on the pros and cons of bee dancing.
"To our surprise, we found that bee colonies were better at collecting food if they were deprived of their dance language," said Dr. Christoph Grüter, a behavioral ecologist at the University of California. University of Mainz. One of the possible reasons could be the human-induced habitat change. In collaboration with his colleagues in Lausanne, Grüter conducted several experiments over several years to examine the effect of dance language on the success of a colony.
There are about 10 species of honeybees that communicate through the wanderer's dance. However, the vast majority of bees, that is, more than 500 species of extremely social and stingless insects, have no dance language. Grüter was therefore interested in the benefits that ambiguous dance brings to the colonies, especially because, as a communication strategy, it takes a relatively long time. Some waggle dances may only last a few seconds, while others may last up to five minutes.
In the experiments, scientists manipulated the conditions affecting some of the bee colonies in order to confuse and disorient the dancing bees. Performed under such conditions, the dance of riddling no longer made sense to the bee public. To create these conditions, rays of light were prevented from falling on the honeycombs. They were also shot in a horizontal position, preventing bees from using gravity to orient themselves.
Another particularly important aspect was to take into account their ability to memorize the location of foods. "Bees looking for food have an excellent memory and can recall a rich feeding place for several days," said Grüter. The research team had to stop the fodder from performing vagina dancing for 18 days to ensure that they could not use their memory to tell other bees where to fly to find the excellent food sources. Foraging bees are older than other members of the colony. In their final phase of life, they no longer work in the hive, but go for nectar and pollen. As a rule, they are in the last 18 days of their life.
Bees without information of the dance of the eddy are more effective in difficult conditions
The team of biologists was surprised by the result that hives with no dance information were more active and produced more honey than beehives using the language of dance. "We were expecting to confirm that the language of dance was important, but our results were exactly the opposite," said Dr. Robbie I 's Anson Price, lead author of the study. "I suspect bees are probably losing interest when faced with a disoriented dance and they go out for food on their own," Price said. The differences are significant: bees in non-language colonies did foraging flights that lasted eight minutes longer and provided 29 percent more honey over the entire 18-day period than bees using waggle dancing.
The conclusion is that some bees, such as Bee Buckfast, a multinational honey bee older than 100 years old used in this study, could do better without social communication. Grüter thinks that the environment and the availability of food play an important role. If there is a large apple tree in full bloom nearby, waiting for information on its location is probably a good strategy. On the other hand, if flowering plants are scattered on balconies or roadsides, it may be better to leave the hive early and feed independently. "In our opinion, the observed behavior can be explained mainly in terms of the time gained by bees," said Grüter.
Perhaps bees could learn to value the value of waggle dance information
By observing the bees, the scientists discovered the extraordinary discovery that these were apparently able to judge the relevance of the informative content of a dance and that they would lose interest in the dance as well. disoriented. "It seems that after a while, they realize that something is wrong," Grüter postulated. "Our results raise the possibility that human beings have created environments in which the language of waggle dance is not well suited," write the authors in their study, recently published in the well-known journal Progress of science.
The idea that bees may be able to assess the quality of information from a dance is an idea that Grüter wishes to deepen in the future. He also plans to repeat the experiments in the Mainz region under different conditions, in urban and rural areas and at different times of the year.
Christoph Grüter heads since 2015 a research team of the organismic and molecular evolution institute of the Johannes Gutenberg University of Mainz. Previously, he headed a research group of the Department of Ecology and Evolution at the University of Lausanne in Switzerland. His group studies how social insects organize and coordinate their collective activities, with communication in the insect colonies playing a central role.
How bees read the dance of the eddies
R. I & # 39; Anson Price et al., Bees feed more effectively without the "language of dance" in harsh environments. Progress of science (2019). DOI: 10.1126 / sciadv.aat0450