NOT JUST THE WIGGLE
Honey bees use social learning to improve waggle dancing
Young honey bees follow dances of older bees to improve performance
Peer-Reviewed PublicationIMAGE: A HONEY BEE IS SUCKING ON THE FLOWER. view more
CREDIT: XTBG
In a study published in Science, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences and the University of California San Diego have shown that honey bees use social signal learning to improve their ability to waggle dance.
Social learning shapes honey bee signaling, as it does communication in human infants, birds, and several other vertebrate species, according to the researchers.
Social learning occurs when one individual learns by observing or interacting with another. Eusocial insects (i.e., insects with an advanced level of social organization) use social learning, but it is unclear whether this learning shapes their communication, which can be remarkably sophisticated and cognitively complex.
Honey bees communicate the locations of resources such as food, water, tree resin (propolis) and nest sites to nestmates by performing waggle dances. Honey bee workers use social learning when following the waggle dance to learn the location and quality of resources. However, it is not known whether following the dance can improve the performance of young waggle dancers or whether the dance is completely genetically pre-programmed (innate).
As previously reported, the waggle dance is usually performed by a successful forager, i.e., one who has located a good source of pollen, nectar or water, and provides information about the presence, quality, identity, direction and distance of the source so that nestmates can find and use it.
The researchers created colonies in which they observed the first waggle dances produced by foragers that either had or had not followed other waggle dancers. Each of the five experimental colonies was established with a single cohort of one-day-old bees.
"As these bees aged, we monitored the colonies until we observed the first waggle dances and then observed the same dancers 20 days later when they had more foraging and dancing experience," said Dr. DONG Shihao, first author of the study.
They found that bees that did not have the opportunity to follow any dances before their first dance produced significantly more disordered dances with larger waggle angle divergence errors and incorrectly encoded distance.
"When the same bees were older and had experience of dance following and dancing, they significantly reduced divergence angle errors and produced more orderly dances. However, they were never able to produce normal distance encoding," said DONG.
The results suggest that social signal learning can improve waggle dancing. But why should honey bees use social learning to improve their waggle dancing?
"Learning is a useful way to refine behaviors for local conditions. We suggest that the unique topologies of each colony's dance floor make it advantageous for novice dancers to learn from more experienced ones. Another possibility is that experienced dancers may transmit distance encodings based on local optic flow to nestmates," said TAN Ken of XTBG.
JOURNAL
Science
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Animals
ARTICLE TITLE
Social signal learning of the waggle dance in honey bees
ARTICLE PUBLICATION DATE
10-Mar-2023
Social learning plays an important role in a honey bee’s ability to “waggle dance,” report researchers, who observed that honey bees not exposed to the dances of older, more experienced nestmates produced disordered dances full of errors. The findings demonstrate that social learning shapes this complex form of insect communication, just as it does in humans, birds, and other social vertebrate species. The waggle dance is a behavior that honey bee foragers use to communicate spatial information about the precise location of a food source to other nestmates. During the dance, the performing bee dances a series of figure-eight-shaped loops in the hive while waggling her abdomen. The length and angle of each waggle run encode the flight distance and direction to the target. Nestmates that observe the dancer learn where the bounty is located. While it’s recognized that there is a genetic component underlying the waggle dance, less is known about whether it is a fully innate behavior or one learned and/or enhanced via social learning. However, according to Shihao Dong and colleagues, if the dance was fully innate, young bees would be able to perform the dance correctly, even if they had never witnessed the behavior before.
To evaluate this question, Dong et al. set up honey bee colonies composed exclusively of newly emerged bees and found that, despite having no prior exposure to the behavior themselves, they began to display the dance a week or two after hatching. However, these inexperienced bees danced dances with significant errors in distance and direction. And, while the accuracy in direction improved as immature bees gained experience, they consistently overestimated distance in their dances throughout their life. Immature bees from control colonies, which were able to observe the dances of older, experienced bees before initiating their own dances, did not suffer similar shortcomings. “Some scholars assume that instinct is by default the ancestral (or primitive) state and that learning is more advanced. The opposite is more rarely considered: Individual learning might be at the root of some behavior innovations that are not partly innate,” write Lars Chittka and Natacha Rossi in a related Perspective. “The study of Dong et al. adds to the growing evidence that complex behaviors are seldom entirely innate.”
JOURNAL
Science
ARTICLE TITLE
Social signal learning of the waggle dance in honey bees
ARTICLE PUBLICATION DATE
10-Mar-2023
Bumblebees learn new “trends” in their behavior by watching and learning
A new study has shown that bumblebees pick up new “trends” in their behaviour by watching and learning from other bees, and that one form of a behaviour can spread rapidly through a colony even when a different version gets discovered.
The research, led by Queen Mary University of London and published in PLOS Biology, provides strong evidence that social learning drives the spread of bumblebee behaviour – in this case, precisely how they forage for food.
A variety of experiments were set up to establish this. The researchers designed a two-option puzzle box that could be opened either by pushing a red tab clockwise or a blue tab counter-clockwise to reveal a 50 per cent sucrose solution reward.
‘Demonstrator’ bees were trained to use either the red or blue tabs, with ‘observer’ bees watching. When it was the observers’ turn to tackle the puzzle, they overwhelmingly and repeatedly chose to use the same method that they had seen, even after discovering the alternative option. This preference for the taught option was maintained by whole colonies of bees, with a mean of 98.6% of box openings made using the taught method.
The importance of social learning to the acquisition of puzzle box solutions was also illustrated through the control group, which lacked a demonstrator. In this group, some bees managed to open the puzzle boxes, but did so far fewer times than those who benefitted from seeing another bee do it first. The median number of boxes opened in a day by the observer bees with a demonstrator was 28 boxes a day, whereas it was only 1 for the control colony.
In an additional experiment, the researchers put both ‘blue’ and ‘red’ demonstrators into the same populations of bees. In the first population, 97.3% of the 263 incidences of box-opening by observers by day 12 used the red method. In the second population, observers preferred the blue method over the red on all days except one. In both cases, this demonstrated how a behavioural trend might emerge in a population in the first place – for the most part, due to experienced bees retiring from foraging and new learners arising, rather than any bees changing their preferred behaviour.
Similar results from similar experiments have been used in species such as primates and birds to suggest that they, like humans, are capable of culture. If bumblebees are capable of this, too, this could potentially explain the evolutionary origin of many of the complex behaviours seen among social insects. It might be possible that what now appears instinctive could have been socially learnt, at least originally.
Dr Alice Bridges, the lead author from Queen Mary University of London, said: “Bumblebees – and, indeed, invertebrates in general - aren’t known to show culture-like phenomena in the wild. However, in our experiments, we saw the spread and maintenance of a behavioural “trend” in groups of bumblebees – similar to what has been seen in primates and birds. The behavioural repertoires of social insects like these bumblebees are some of the most intricate on the planet, yet most of this is still thought to be instinctive. Our research suggests that social learning may have had a greater influence on the evolution of this behaviour than previously imagined.”
Professor Lars Chittka, Professor of Sensory and Behavioural Ecology at Queen Mary University of London and author of the book ‘The Mind of a Bee’, said: “The fact that bees can watch and learn, and then make a habit of that behaviour, adds to the ever-growing body of evidence that they are far smarter creatures than a lot of people give them credit for.
“We tend to overlook the “alien civilisations” formed by bees, ants and wasps on our planet – because they are small-bodied and their societies and architectural constructions seem governed by instinct at first glance. Our research shows, however, that new innovations can spread like social media memes through insect colonies, indicating that they can respond to wholly new environmental challenges much faster than by evolutionary changes, which would take many generations to manifest.”
JOURNAL
PLoS Biology
Puzzle-solving behavior spreads through bumblebee colonies
Bees that learned from others were more adept and preferred the learned solution over alternatives
Peer-Reviewed PublicationIMAGE: BUMBLEBEES CAN LEARN BY WATCHING A TRAINED BEE DEMONSTRATING ONE OF TWO WAYS TO SOLVE PUZZLE FOR A SUGARY REWARD, THEN COPY THE BEE TO SOLVE THE PUZZLE IN THE SAME WAY view more
CREDIT: DIEGO PEREZ-LOPEZ, PLOS (CC-BY 4.0, HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)
Bumblebees learn to solve a puzzle by watching more experienced bees, and this behavioral preference then spreads through the colony, according to a study publishing March 7th in the open access journal PLOS Biology by Alice Dorothy Bridges and colleagues at Queen Mary University of London, UK.
Social animals like primates are skilled at learning by watching others, and previous work has shown that individual bees can learn tasks in this way, but it remained unclear whether these new behaviors would then spread through the colony. To investigate, researchers tested six colonies of bumblebees (Bombus terrestris) using a puzzle box that could be opened by rotating a lid to access a sugar solution. The bees could rotate the lid either clockwise or anticlockwise by pushing one of two different colored tabs.
The researchers trained bees to use one of these two solutions and then released these ‘demonstrator’ bees into a foraging arena alongside untrained bees and filmed them over a period of six to twelve days. Foraging bees with a demonstrator opened more puzzle boxes than control bees, and used the same puzzle solution that the demonstrator had been taught 98% of the time, suggesting that they learned the behavior socially rather than stumbling upon a solution themselves. In experiments where multiple demonstrators were each taught a different solution to the puzzle, untrained bees initially learned to use both methods, but over time they randomly developed a preference for one solution or the other, which then came to dominate in that colony.
The study is the first to document the spread of different behavioral approaches to solving the same problem in bees. The results provide strong evidence that social learning is important for the transmission of new behaviors through bumblebee colonies, as has previously been shown in primates and birds, the authors say.
Bridges adds, “These results in bumblebees, which are tiny-brained invertebrates, echo those previously found using similar experiments in primates and birds - which were used to demonstrate the capacity of those species for culture.”
Bees feeding from a puzzle box opened by pushing the blue tab
CREDIT
Alice Bridges (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)
In your coverage, please use this URL to provide access to the freely available paper in PLOS Biology: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002019
Author Interview: https://plos.io/3IFJz7c
Citation: Bridges AD, MaBouDi H, Procenko O, Lockwood C, Mohammed Y, Kowalewska A, et al. (2023) Bumblebees acquire alternative puzzle-box solutions via social learning. PLoS Biol 21(3): e3002019. https://doi.org/10.1371/journal.pbio.3002019
Author Countries: United Kingdom, China
Funding: This study was funded by an Engineering and Physical Sciences Research Council programme grant, “Brains on Board” (ref. no. EP/P006094/1 to L.C.) and a Queen Mary University of London PhD studentship (to A.B.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
JOURNAL
PLoS Biology
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Animals
COI STATEMENT
Competing interests: The authors have declared that no competing interests exist.
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