Some bees—about 10 of approximately 500 existing species—speak dance. That is, they waggle their behinds at hive mates for anywhere between a few seconds and five minutes, using a social language that evolved over 20 million years to pass on information about the location of food sources. Or, they did.
New research shows that the current buzzword for these industrious creatures is “efficiency.” Bees are ignoring and abandoning dances and humans may be to blame for the change.
A study in Science Advances by biologists at the University of Lausanne in Switzerland and at Johannes Gutenberg University Mainz in Germany examined the “waggle dance” and its advantages in communities of Apis mellifera, a species of honeybee. This dance communicates the location, odor, and presence of high-quality food or nest sites to mates, so researchers were expecting that hives deprived of dance information in experiments would suffer, making less honey.
Instead, they discovered something unexpected: some dancing bees are losing their groove, and when they do, the communities do better, collecting more food and making more honey, faster.
The bees’ classic mode of communication, the waggle dance, is being replaced with what appears to be a more practical but less poetic approach to survival. Instead of watching waggle dances for clues as to good food sources, some honeybees were simply getting out and seeking food independently. The biologists believe that human changes to the environment may be rendering the old form of exchange irrelevant.
They tested eight honeybee colonies, filming hives where about 15,000 to 25,000 worker bees total operate for about nine days. Some hives operated as usual. Others were deprived of waggle-dance messaging—the hives were darkened and their orientation shifted to cause the bees confusion so that the information dancers sent was difficult to discern and senseless.
The scientists analyzed video footage of the hives and measured how much honey the colonies were producing in what amount of “fly time.” Bees that received information from disoriented dances seemed capable of discerning between a useful waggle and random moves, the researchers say, as evidenced by how little time they spent watching dancers. “[O]ver time, bees exposed to disoriented dances showed reduced interest in dancing nestmates…[and] did not waste time waiting for information,” the study notes.
In other words, the bees quickly adapted to change and learned to ignore language that wasn’t conveying anything useful about where to get food. They simply foraged independently, ending up with much more honey than bees relying on dance data.
The biologists argue that their experiment may help to explain the effect of human activity on honeybee behavior. They note that masses of flowering crops, planted by humans, are easy for honeybees to find and profit off of in spring but are more difficult to forage once flowering is concluded. Dancing in tough environments with few valuable food sources may not be worth the expenditure of effort, researchers hypothesize, and may be causing bees to give up their ancient tongue. Their paper “raise[s] the possibility that human impact may have created landscapes and temporal periods to which the honeybee ‘dance language’ is not well adapted.”