Bee Science with Dewey Caron: The Honey Bee Dance Language

The Honey Bee Dance Language

Dr. Dewey Caron

Hi, I'm Dr. Dewey Caron. I come to you again from Portland, Oregon.

I present another audio postcard in my once-monthly Beekeeping Today mini-series podcast. Be Science with Dr. Dewey Caron.

This is the seventh installment in this series. In each episode, I seek to blend research, field experience, and seasonal context Focusing on the why behind honey bee biology and behavior. I welcome your suggestions for timely topics.

I'll start with a question Do you remember what it was that first got you interested in honey bees? My interest as a graduate student in insect ecology is the study of relationships of insects to other organisms in their environment. was the opportunity to study insects at the population level.

That is what I did for an obscure insect group at University of Tennessee. In contemplating my PhD, while most entomologists study insect populations to understand a life cycle weakness in a pest to better tune controls to kill them, With honey bees, I could study their populations to seek to keep them alive. Although I understand them more now than back sixty years ago.

Yep, all that many years ago 1966, there's much I still do not understand. Like you, who I hope, I continue to learn things that amaze me in honey bees One behavior that truly is amazing is bee dancing. Picture this.

honey bee, one of hundreds, leaves her home. She might be a naive forager, just learning her way about. An older forager who is foraging a failing source, or maybe a scout bee, out specifically looking for something Such bees use a variety of senses, smell, color vision, movement, for example, and then she discovers a patch of flowers.

She might collect pollen, or probe flowers for nectar, or perhaps collect both Then sometimes, without even taking what might be called a full payload, she returns to her home. There she tells her sisters about her discovery Amazing. She will tell them precisely where the food is, those flowers she discovered, how far away it is, and even tell them how good it is.

Fascinating. Our understanding of honey bees is that with a simple, relatively small brain, with something like nine hundred and fifty thousand neurons, compared to a hundred billion neurons in our human brain, And a brain size that is one-hundred-thousandth the size of our human brain, they are capable of the most complex cognition, capable even of language. Bees are downright fascinating.

Our honey bee, what we call the European or Western honey bee, is the only social bee that has successfully invaded northern climate. All the rest are tropical. Although Apis dorsata, the giant bee, which builds a single comb, migrates to more temperate climates at higher elevations in the summer, before returning to lower tropical climates.

to overwinter. The ancient range expansion into the cold, temperate latitudes of Europe, after migrating out of the tropics, meant that the European bee had to adapt to long, cold winters and short, highly seasonal nectar flows. Food storage and preservation became paramount.

They evolved behaviors by which they fermented pollen to form bee bread, a form of pollen far more durable than raw pollen. and their energy source, raw nectar, is acidified and dehydrated to a lower moisture content below eighteen point six, the level below which yeasts, bacteria, and other nasties cannot germinate and cause spoilage. As honey bees age, they will take up the most hazardous duty of their lifetime, leaving home to forage for resources of food, water, or plant resins.

not to be enjoyed and savored on their journey, but to be brought back to the home. There they will communicate, to recruit, sisters to the very same sources they have just left as they return from the field. To be sure, leaving home is not a choice.

The message to leave the hive and to begin foraging is a result of bees undergoing a major shift in their physiology as they transition duties. Prior to foraging, bees exclusively work in their home. But eventually their hypopharyngeal glands become less effective, and with it, changes in brain morphology, neurochemistry, and gene expression.

She changes her job, sort of a middle-aged crisis, I suppose, becomes a worker of food processing and storage, and wax production and comb construction She will change her duties once again, just about retirement age, I suppose, as hormones dictate yet another change, so she becomes a forager Thomas Seeley, in his 1985 book Honeybee Ecology (Princeton University Press), suggests, foraging by honey bees is a social enterprise. We might think of a honey bee colony as a machine that has as its job to extract energy and other resources from the environment. That is the work of forging.

A bee might spend a great deal of time communicating this information to others in the hive. The time she spends telling others about what she has found reduces her individual food collecting efficiency. But her efforts allow the colony to make the greater gain.

Honey bees typically gather the food they consume during a whole year in a period as short as three weeks to a couple of months. Scale hive records show that colonies might gain weight for only about ten to fifteen weeks, and for the remainder of the year, 35-40 weeks, lose weight. In those weeks of gain, they must store enough food to last for those 35 to 40 lean weeks The ability of honey bees to share information about food sources allows colonies to achieve this high degree of foraging efficiency so that they might survive those long periods of adverse weather With so many worker bees living in a confined space of a nest, it is not surprising that multiple forms of communication exist for the colony to function as that cohesive, coordinated social unit For example, the smell of the nectar and pollen collected in the field provides a great deal of information needed, so new foragers find a specific food source, the best that might be available at that time and space.

But communication about location of food resources is different. The workers don't leave anything to chance. They pass specific information via bee dancing.

for which specific taste, smell, location, distance, and how great the source is, all are used to motivate recruits to go get it The major breakthrough in our understanding of honey bee communication came with Professor Karl von Frisch, by a series of elegant and painstakingly thorough series of experiments, Some performed during the World War II years in his native Austria, reported that he could read communication signals of foragers He described the significance of distinct behaviors, which we now call dance language, so labeled because the behaviors are repeated movements. that many individuals describe as resembling dances. One, two, three.

One, two, three. One, two, three, dancing. and decode what the dancing information meant.

We now know dance language codifies basic information to pass from dancer to a recruit. The world heard about his discoveries when Von Frisch came to the US to tour US universities. Cornell was one stop, and they quickly developed a hundred nineteen page paperback book on dance language in 1950.

It has been reprinted and revised as Von Frisch and others have added more details on dance behavior. He also followed with a more technical book, which was then translated into English, and also, interesting, a book on his journey deciphering bee communication. You can see the end notes for these references.

One development following the early studies was defining how sound is associated with a dance. Early researchers searched in vain for sound receptors. because they could find none, concluded that sound was not an important part of honey bee communication.

More recently we have come to understand that this is not true. We now know Honey bees hear through the Johnston's organs, which are sensory receptors on their antenna. When the antenna are in receiving mode, They are held perpendicular to the face of the bee, roughly at a ninety degree angle to each other.

Experiments performed leave little doubt that sound is very important communication of distance to food resources And experiments have de as have now expanded that now reveal that dance language is also a means of communicating suitability of potential nest sites and water sources in a new home location. Dancing is bee language for more than just food. So how does dance language work?

When a worker bee finds a resource her calling needs, the information about the location of the resources is conveyed by the repetition of the behavior, a dance. Two dances with an intermediate dance, although recently this is described as a single dance with three variations, are used by honey bees to convey n convey resource location information to nestmates. Dances are mostly performed by foragers termed scouts.

These are older age workers that look for profitable food sources. The number of scouts will vary. Sometimes there are very few, but when Forge is more limited, more scouts will exist.

The simplest dance, now variation one, is the round dance. It signifies the source is close, usually less than 100 yards But how close varies by different subspecies or races of honey bees The round dance really is a modified waggle dance. It is a circular movement without the waggling phase.

The dancing bee with quick, short steps runs around in narrow circles on the comb face. Basically one time to left, then changing the direction to circle to the right. One, two, three, left.

One, two, three, right. Circle to left, then right. The bee might dance for several seconds or as long as a couple of minutes.

She may stop, distribute some of the contents of her honey stomach, and resume dancing is an exaggerated walking, almost running movement. It's not just simply moving along. The liveliness of the dance is influenced by source richness.

With more vigorous and faster dancing for nectar of higher sugar concentration. Powerful food odors cling to the body of the dancing forager. These odor clues communicate the floral source of the food The round ants convey some meshes that food is close to their home.

How close varies among different races of bees. Bees, like people, have different dialects. And like us, sometimes when we have trouble understanding someone with an accent, well, so do the bees.

What one race a bee indicates is a distance of 50 yards, let's say, may mean a greater or shorter distance to a bee of another race. Initially, von Frisch thought that the round dance meant collect nectar and the waggle dance meant collect pollen. His technique, how he discovered dance language, was to provide a flavored syrup at a feeding station.

The feeding stations who initially were fairly close, just uh as an ease in the experiments An assistant would color mark a bee as it collected the offering, that scented sugar syrup, and then von Frisch or another associate would watch its behavior when it returned to an observation hive Well, when he moved his feeding station to a greater distance, he realized that dancing conveyed direction distance, not an expression for type of food. This is an important story in the sense that science changes with time as we gather more information. it is not necessarily locked in that one person is correct and another is wrong.

It does indeed change, and this is one example. In this case, von Frisch himself. discovered that his original interpretation was not correct, and he himself changed it.

The most intricate dance behavior, not the round dance, is the waggle dance It's also sometimes termed waggling dance or the figure eight dance or the waggle dance Bees translate environmental clues, such as the position of the sun's azimuth, coupled with internal information of time of day. gravity and energy expenditure to inform hive mates of potential food or home sites at greater distance In a waggle dance, the dancing bee runs in a narrow half circle to one side, then does a sharp turn, and runs in a straight line while vigorously waggling her abdomen from side to side. Circle to the right Back to the same orientation.

Doot. Circle to the left. Back to the same rough orientation.

Do do do. And a doo-doo-doo here is her waggling, vigorously whacking waggling her abdomen from side to side. The circles are usually from one side then to the other.

And so it looks like roughly a figure a pattern, and hence sometimes what it is called. Most critically, very important, that straight portion is always performed with the bee orienting her body at the same position relative to gravity on the vertical comb. As in the round dances, the bee may not start the waggling position of the dance at the same exact point every dance cycle, but there is little variation in orientation of her body when doing that waggling or in that duration of the waggling.

Waggling duration is the distance communication. So that going in those circles and that roughly figure eight of waggling your abdomen, do-do-do-do, circling to the right, coming back to a rough same orientation, do-do-do-do, circling to the left. What is being coded then is this language, information.

A bee cannot merely point towards where the food is on the vertical comb in her dark hive. The scout bee's orientation of her body conveys direction to the food. Round dances convey neither distance nor direction, other than that food is close.

The scout bee's orientation of her body conveys direction to the food relative to gravity. When food is in the direction of the sun, not literally flying up toward the sun, but the sun's azimuth position, The scout performs the waggle portion of dance while moving straight up on the comb away from gravity When the food is directly away from the sun, the waggle portion is performed straight down the comb toward gravity. This information is hardwired into the memory of workers.

They know up means towards and down away from. Of course, the discovered foo source might not be directly towards the sun's azimuth, or directly opposite. Positions to right or left of the sun's azimuth mean scouts dance to the right or left of gravity, respectively.

Bees might not be right or left-handed. Think of directions as a compass of 360 degrees. Towards the sun's azimuth, zero degrees.

To the east is zero to 180 degrees. Directly away is 180 degrees, and then west as the last of the compass, 180 to 360 or 0 again Bees to get the message crowd onto dancing bees, touching with antenna, and it turns out listening as well, with their feet, because the sound that is being produced is transmitted through the comb. During the waggling, the sound produced is with wing muscles and that abdominal waggling.

It's a frequency, a low-level frequency, 250 Hz. There's a direct correlation between a sound production time and a distance a bee must travel to a food source. The further the distance to the food source, the longer the waggling and sound segment of the dance Return to the right.

Return to the left. is going to signify food that is further away. The longer she's w waggled, say she waggles three seconds or more, means that the resource is located a greater distance, three thousand yards or more, from their home.

This is an interesting aside. Von Frisch measured the time for a complete dance circuit, that is, a waggle run plus the walking back to the starting point to begin another waggle, thinking this was how bees communicated distance. He did not reel the importance of the sound.

We now believe the best correlation is time of sound during waggling. The mystery remains, though, however, to where the bees keep the stopwatch, to accurately record the time of waggling. Again, this is an interesting example of how sound, of how further discoveries can even further our information.

It's not simply just what we are learning from one series of experiments. but continued by other researchers by other labs. In a dark hive, recruits that follow the waggle dance of a scout bee.

In addition to determine the direction and distance of the food from the hive, get other clues to its profitability, that is the amount of food available in the patch. degree of sugar concentration of nectar, how easy it is to forage the flowers. And they can smell any flora or rooters clinging to the dancer's body and get a taste of the source.

If the food source is close enough, so the odor is not lost as the bee flies through the air. If the bee has collected pollen, that odor likely remains. and or a taste sample of the nectar.

The dancer will give that if she is begged to do so. The tempo of the dance, that is the number of waggle circuits per unit time, is an important component of the performance. It's saying all of those aspects are saying something about the new source.

The food source of course stays the same. But the sun's azimuth position moves across the sky as the sun moves along the horizon from dawn to dusk. But gravity in the hive remains the same.

The angle of the waggling position, where she starts that portion, that waggling portion itself, will change as the day progresses. The answers adjust for this, sometimes in as little as for 30 minutes. So they're not giving false information of what has been.

They are giving very accurate information. Food or water sources found by Italian bees, those that are very close, between about 10 and 30 yards from the hive, are conveyed by performing a crescent or sickle dance. This is that third variation.

This dance approximates an open figure eight. Instead of circles, as in a round dance, the circles become more like two lobes This is clearly a transition dance in which the recruits can approximate the direction by estimating an imaginary line which runs from the middle of the crescent base through the middle distance between the two lobes or ends of the crescent. Get your protractor out to try to figure what this is doing.

Somehow the bees can able are able to do it. Bees can do the math. A dance indicating a food source just beyond 10 meters, which would went up to that would have been a round dance, looks similar to a round dance.

The dance changes as food distance increases. The two lobes gradually close together to resemble the figure eight or that waggle dance. If you want to see this diagram of each of these, I recommend that you look at my book, honey bee Biology and Beekeeping, for excellent diagrams of these dances produced by John Zawalzlak.

I also provide information how Von Frisch used fan and step experiments he devised to determine the accuracy of the direction and distance information in the dancing. That same chapter 8 discusses dance language in swarming. There are several videos to view waggle dancing.

I provide information for two in the end notes Several factors affect how soon, how long, or how enthusiastically a scout will dance. Scouts start performing the waggle dance after only one trip to a rich food source. However, they may require several trips to a moderately good food source before beginning to dance.

Scouts will dance for a longer period of time if the food source is profitable. In contrast, a scout might seize dancing if she is discouraged from doing so. For example, if a hive is full of honey, or for full of brood, Or there is a lot of pollen that are is being brought in and stored.

There's no place to deposit more food into cells. Or if so much food is coming in that the house bees are fully occupied in unloading and storing it, scouts will find a difficult it difficult to unload their nectar and will be discouraged from further dancing and foraging, no matter how rich the food source might be. Other species of honey bees also dance on their vertical comb.

But however, in the smallest species, Apis florea, they construct their comb with a flat portion above that hanging vertical part. And their scouts dance there on that flat portion. And so they merely point their body in the direction of the food No gravity com conversion is needed in that one species.

All the others have to do the language. In conclusion, I find dance behavior fascinating. I hope you might too.

Thanks to Von Frisch and many other scientists, we can interpret the significance of the behavior, i.e., speak bee. For bees, speaking bee is critical to their collecting enough protein and carbohydrate resources To survive winter in our temperate climate, or when swarming to find a new home. Bee language helps us profit.

They store a surplus so we can harvest the extra Let me finish with a bit of poetry, courtesy of Stephen Strait from his latest book, Affirmation. The earth still spins, little bees, but we dread what lies ahead Save yourselves and save us, please, before our global hive is dead. Bees know the world is round.

Where zero is, how to dance, the angle of the sun, even when it's on the other side of the world, how to make food that lasts for thousands of years. I, on the other hand, don't know anything. Exhausted by the smoke of doubt and fear, I long instead to be stung again by wonder, by joy.

Thank you, and be well.