The Demise of Bee Dancing Has a Surprisingly Positive Outcome

Good news: The death of the "waggle dance" won't mean the death of bees.

Bees, like humans, dance to communicate. While a team of rugby players might dance the threatening Haka to tell the other team “You’re screwed,” some bees do the “waggle dance” to tell one another where to find nectar. This important form of communication is very well established. That’s why a Science Advances study, showing that bees who don’t do the waggle end up being better at finding food, seems so counterintuitive.

The study, published earlier in February, focuses on the European honeybee (Apis mellifera), which is known to get down and do the waggle. In 1927, the Nobel Prize-winning bee scientist Karl von Frisch, Ph.D., showed that bees who go out foraging use the steps of the waggle to convey precise information about the whereabouts of nectar to the other bees in the hive. But in this new study, scientists at the University of Lausanne in Switzerland and at Johannes Gutenberg University Mainz in Germany blocked the bees from doing the waggle in an attempt to see how important the dance really is when it comes to foraging for nectar.

Over periods lasting 12 to 18 days, they filmed the activity of eight bee colonies, some of which were allowed to dance freely to communicate, while the others were not. The scientists curbed dancing by messing with the hives’ brightness and orientation relative to the sky: When a hive is dark and has no view of the sky, the bees become disoriented, making it hard for them to discern a geographical relationship between food and home. So, any information that dancing workers from those hives try to convey to their colonies after a day of foraging isn’t particularly useful.

Sure enough, that’s what the team observed in the footage of dancing bees from disoriented hives. The workers who watched the disoriented dancers couldn’t glean any useful information from the moves.

Eventually, those worker bees got sick of all the bad dancing and stopped watching. “Over time, bees exposed to disoriented dancers showed reduced interest in dancing nestmates,” writes the team. This observation is crucial to understanding how the dance-free hives ended up being the most productive.

Honey bee on a flower
Some bees use the "waggle dance" to convey to one another the location of nectar. But the waggle, researchers are finding, isn't absolutely crucial to foraging success.

Less Dance, More Nectar

Every day during the experimental period, the team weighed the hives to indirectly measure how much foraging they were doing. “On good foraging days, bees leave the colony in the morning and the weight decreases,” they write. “This loss of weight is a good indication of foraging activity.” In other words, if the dancing conveys usable information about where to go, more bees would be expected to leave in the mornings, making the hive lighter.

However, that’s not what happened. “We found that the foraging activity of colonies, measured as the mass of foragers leaving the colony in the morning, was, on average, 23% higher in the [disoriented treatment] than in the [oriented treatment],” the team writes. Even if the bees in the disoriented hives weren’t getting useful information from their dancers, they were leaving the hive anyway.

The team’s explanation for this phenomenon is, in its own way, just good bee common sense. Bees that watched bad dancing still needed to go foraging, so they eventually stopped bothering with the dancers and just went hunting for nectar on their own. As the team put it, they “did not waste time waiting for information.” This observation is in line with previous research showing that bees use their past experience to inform how they use social information.

Bumblebees are social insects which form colonies with a single queen. Colonies are smaller than those of honeybees, growing to as few as 50 individuals in a nest. Female bumblebees can sting repeatedly, but generally ignore humans and other animals. Cuckoo bumblebees do not make nests; their queens aggressively invade the nests of other bumblebee species, kill the resident queens and then lay their own eggs which are cared for by the resident workers. Bumblebees have round bodies covered in soft hair (long, branched setae), called pile, making them appear and feel fuzzy. They have aposematic (warning) coloration, often consisting of contrasting bands of colour, and different species of bumblebee in a region often resemble each other in mutually protective Müllerian mimicry. Harmless insects such as hoverflies often derive protection from resembling bumblebees, in Batesian mimicry, and may be confused with them. Nest-making bumblebees can be distinguished from similarly large, fuzzy cuckoo bees by the form of the female hind leg. In nesting bumblebees, it is modified to form a pollen basket, a bare shiny area surrounded by a fringe of hairs used to transport pollen, whereas in cuckoo bees, the hind leg is hairy all round, and pollen grains are wedged among the hairs for transport. Like their relatives the honeybees, bumblebees feed on nectar, using their long hairy tongues to lap up the liquid; the proboscis is folded under the head during flight. Bumblebees gather nectar to add to the stores in the nest, and pollen to feed their young. They forage using colour and spatial relationships to identify flowers to feed from. Some bumblebees rob nectar, making a hole near the base of a flower to access the nectar while avoiding pollen transfer. Bumblebees are important agricultural pollinators, so their decline in Europe, North America, and Asia is a cause for concern. The decline has been caused by habitat loss, the mechanisation of agriculture, and pesticides.
The end of the waggle won't mean the end of bees.

Is Dancing Dead?

This isn’t to say that the waggle dance is dead or unimportant, but it does show that bees can do without it. Just as rugby players don’t need the Haka to show how fierce they are, bees under certain human-made conditions, it seems, don’t need the waggle dance to know how to find food.

This is good news for bees, since humans are increasingly turning their habitats into farms and cities that might disorient them — creating bad dancing — but maybe the bees will just stop relying on their friends and go out on their own in those situations as well. The observations in this study, the team writes, raise the “possibility that human impact may have created landscapes and temporal periods to which the honeybee ‘dance language’ is not well adapted’.” And that’s just as well; even if the waggle dance dies out, the bees will keep on moving.