How Karl von Frisch deciphered the waggle dance
The waggle dance of honey bees was known to beekeepers long before Karl von Frisch began his studies of this behaviour. For example, in 1823, a German beekeeper, N Unhoch, wrote: “To many it will seem ridiculous or even incredible if I mention that bees too indulge in certain pleasures and jollity, and that at times they even set about a certain dance after their fashion … What this dance really means, I cannot yet comprehend…” (translated from the German).
Testing colour vision
Karl von Frisch began studying this ‘dance’ in the spring of 1919, when he was 32 years old and was a young professor in the Zoological Institute of the University of Munich. This institute occupied a building that had housed a monastery, so it had a quiet courtyard, which was handy for studies of honey bees. Von Frisch had used it extensively already for
his experiments on bees‘ colour vision and sense of smell. To study their colour vision, for example, he put a hive in the courtyard and trained bees from it to forage from a shallow dish of sugar water that sat on a coloured card. Shortly after one bee found this food bonanza, others began to arrive and soon there was a packed crowd, at which point he removed the dish of food.
The next day, von Frisch tested the bees for colour vision by presenting them with an array of empty dishes. One dish sat on a coloured card (the same colour as during the training) and all the other dishes sat on cards of various shades of grey (Diagram 1). He would see on which dish the bees gathered in seeking more food. He found that if the dish of food had been set atop a blue card on the first (training) day, then on the second (testing) day, the bees would gather only on the empty dish that sat atop a blue card. The bees did not confuse it with any dish atop a grey card. Soon, the bees lost interest in all the dishes because all were empty.
On the third day, von Frisch would start another test. Again, he put out one dish filled with sugar water, but this time he put it atop a card of a different colour, such as yellow. And again, once one bee found the refilled dish, loaded up, and returned home, other bees arrived in swift succession. The testing on the fourth day unfolded as before: the bees would gather only on the dish that sat on a card of a colour that matched what they had experienced the day before, ie, yellow. The bees always passed von Frisch‘s test, except when the test colour was red; then the bees picked the dishes that sat atop the dark grey cards as well as the dish atop the red card. These experiments showed that worker honey bees possess excellent colour vision but are colour blind to red. Red objects appear dark grey to worker bees.
Testing high-speed messaging
In the spring of 1919, however, Karl von Frisch was not focused on testing further the bees‘ colour vision. Instead, he wanted to investigate how the first bee to find a dish with filled with sugar water is able to spread quickly the news of her discovery. To begin this new line of study, he arranged for a beekeeper to bring to his laboratory a small colony housed in an observation hive (Diagram 4). It was set beside a window in a laboratory room in the zoological institute. The window was left open, so the bees could fly outdoors and come home without difficulty. Von Frisch began his investigation by setting out a dish of sugar water and then marking the first 20 or so bees that visited it. Each bee received a dot of red paint on her thorax. Next, he shut down his feeding station for a few hours … long enough for the red-dotted bees to lose interest in it.
As soon as von Frisch saw his marked bees sitting quietly together inside the observation hive, usually near its entrance, he refilled his feeder. Then he waited for one of these bees to check on its condition and discover that it was again a bonanza food source. He saw something marvellous when eventually one bee came to his feeder, loaded up, and flew back to the hive. In his words: “she performed a round dance, in which the red-spotted bees sitting nearby showed lively interest … and then left the hive to hasten to the feeding station.” Other (unpainted) bees also followed the dance and soon they too showed up at the feeder. It was clear to von Frisch that these round dances were calls to action.
Tail wagging
While doing these experiments, he noticed another form of dance being performed by bees in his observation hive. He called it the tail-wagging dance. Many of these tail-wagging bees had returned home with filled pollen baskets. At this point, von Frisch made the error of concluding that honey bees have two distinct types of recruitment dance: round dances to announce rich sources of nectar, and tail-wagging dances (hereafter called waggle dances) to announce good sources of pollen (Diagram 2). Looking back, we can see that when von Frisch put his sugar water feeder in the courtyard of the zoological institute, hence near his observation hive, he created, unintentionally, a strong correlation between food-source type (nectar v pollen) and food-source distance (near versus far). In 1923, he reported his findings on the dances of honey bees, in a 186-page book titled Über die ’Sprache’ der Bienen (On the ‘Language’ of Honey Bees).
Diagram 2 Summary of Karl von Frisch‘s initial interpretation of the messages of the round dances and waggle dances of honey bees
Diagram 3 Experimental layout, and the result, of Karl von Frisch’s first experiment to see if honey bees have a ‘word’ for distance in their dances.
Diagram 4 Karl von Frisch’s observation hive, 54cm wide and 47cm high
Discovering a misinterpretation
Two decades passed before von Frisch discovered that he had misinterpreted the two forms of the bees‘ dances. This happened in the summer of 1944, when he and most of his laboratory group moved from Munich to his country home in the village of Brunnwinkl beside the Wolfgang See, a beautiful lake in the Austrian Alps. (Munich was heavily bombed during the second world war, so the zoological institute lay almost entirely in ruins in 1944.) His discovery of his misinterpretation of the bees‘ dances emerged from a study that his colleague, Dr Ruth Beutler, was conducting that summer. She was running a sugar-syrup feeding station scented with thyme 500 metres (1640 feet) from her study colony‘s hive, and she wanted her bees to work instead at a feeding station only 10 metres (33 feet) from the hive. Karl von Frisch advised her to present her bees with a rich sugar syrup scented with thyme at the 500-metre station, and to set up an identical feeding station 10 metres from her study colony’s hive. He thought that ‘nectar’ foragers exploiting the thyme-scented sugar-water feeder 500 metres away would produce round dances that would activate other foragers from her study colony to search all around their hive for a thyme-scented nectar source. Beutler followed his advice but had almost no success; nearly all the recruited bees appeared at the 500-metre feeding station. Now von Frisch began to wonder: did the distance of the feeding station influence the dancing of the bees? Do the bees have a ’word’ for distance in their dances?
To answer this question, von Frisch and Beutler performed the experiment shown in Diagram 3. They set up two identical sugar-water feeders, one 10 metres (33 feet) from the hive and the other 250 metres (820 feet) from the hive. Both feeders were placed in the same direction from a colony living in an observation hive. Soon, they had ten individually labelled bees from this colony visiting their two feeders, with five bees working each one. Then they watched how these ten bees behaved inside the hive. This was a breakthrough moment. It was clear that the five bees from the nearby feeder performed round dances, and the five bees from the distant feeder performed waggle dances (Diagram 3).
Moreover, it soon became clear that waggle dances were performed by both collectors of nectar and collectors of pollen. Von Frisch now realised that he had misinterpreted the correlation that he had seen, 20 years earlier, between forage type (nectar v pollen) and dance type (round v waggle). In his 1967 book, The Dance Language and Orientation of Bees, he mentions (on page 5) that he had seen in his observation hive waggle dances being performed by bees that lacked pollen loads, but that he had interpreted the dances of these bees as those of pollen collectors that had already scraped off their loads.
Diagram 5 How honey bees encode direction and distance information in their dances
Testing distance and direction
Von Frisch then investigated how a successful forager indicates the distance and direction to a rich source of food using the waggle dance. He and his colleagues soon deciphered the bees’ ‘code’. Distance is indicated by the duration of the waggle run in each dance circuit. Direction is indicated in a way that is less obvious to us but makes good sense to the bees. They use the sun’s azimuth (its compass direction) as a reference direction, and they indicate to other bees the angle of their rich food source relative to the sun’s azimuth by pointing their waggle runs at the same angle relative to straight up on the comb. (Diagram 5). This was a beautiful discovery. It is no wonder that Karl von Frisch was awarded the Nobel Prize in Physiology or Medicine (in 1974) for deciphering the bees’ marvelous dance language.
Video reveals two dances are one
There was, however, one small part of the work of von Frisch that was still not quite right. It was the terminology of ‘round dances’ and ‘waggle dances’ that he had begun to use in the 1920s and continued to use for the rest of his life. (He died in 1982.) He called them “two separate words in the dance language”. We know now, however, that it is an error to say that honey bees have two discrete dances: round and waggle. Several investigators have used the tools of digital video-recording and slow-motion playback to examine the bees’ dances more carefully than was possible before. These studies have revealed that we should refer to all the bees’ recruitment dances as waggle dances. Why? It is because in every circuit of a recruitment dance performed by a honey bee, regardless of the distance to the recruitment target, there is a waggle phase. So, even when a rich flower patch is nearby (less than 50 metres, or 165 feet) from a hive, the dances performed to advertise it contain information about its direction and distance from the hive.
The ability of worker bees to use the directional information in dances for nearby food sources was tested recently in an experiment in which investigators trained ten bees to each of two sugar-water feeders that were identical in their scent and in their distance from the hive, but were in opposite directions from the hive. One feeder held a concentrated sugar solution and the other held a dilute solution. The investigators found that even when the two feeders were positioned only 20 metres (66 feet) from the hive, 70% of the recruits arrived at the feeder that provided the rich sugar solution and therefore was advertised by lively waggle dances. (Note: all the bees in this experiment had their Nasanov glands sealed shut, so there was no difference between the two feeders in how strongly the bees marked them chemically.)
There can be little doubt that the stronger recruitment to the richer feeder came about by the recruited bees acquiring directional information from the waggle dances they had followed inside the hive. So, even when a rich food source is near a colony’s home, the bees visiting it can direct their hive mates to it when they perform their waggle dances.
Karl von Frisch (1886–1982) was born in Vienna to surgeon Anton von Frisch and Marie Exner. His family converted a mill house in a village (Brunnwinkl) in the Austrian Alps into a comfortable summer home. The summer hours spent observing and collecting butterflies, moths, and beetles sharpened his powers of observation of small animals. At school, he was a diligent student, but could not do mathematics and physics. Fortunately, his teacher of these subjects let him slip through, so he could go on to university.
Initially, von Frisch studied medicine at the University of Vienna but after two years he switched to studying zoology at the University of Munich. Here he began his life’s work of studying live animals by means of carefully thought-out experiments. His first discovery came in 1910: fish (minnows) are not color blind. This led to his studies of color vision in bees, which began in 1912, and was pathbreaking. Until then, it was widely believed that insects are color blind. During the first world war, he worked for the Red Cross hospital in Munich. After the war, he resumed his studies there with honey bees.
Between 1921 and 1925, von Frisch rose to Professor of Zoology, first at the University of Rostock and then in Breslau. He and his students focused on hearing in fish, and they discovered remarkable similarities in how vibrations in water (fish) and in air (humans) are transmitted to sensory cells. In 1925, he returned to Munich, now as the professor in charge of the zoological institute. Every summer, he returned to Brunnwinkl to study further the sensory abilities of bees. For many years, he sought to understand why some sugars taste sweet (so are attractive to bees) and others do not. This work did not yield exciting results, but it did lead to him taking a second look at the bees’ dances.
Photos: Left: Karl von Frisch as he looked when he bagean his studies of the communication dances of honey bees. Right: Karl von Frisch (foreground) with students. Photo courtesy Rosemarie Lindauer.
Further reading
Frisch, K von (1923). Über die “Sprache” der Bienen. Fischer Verlag, Jena
Frisch, K von (1947). The dances of the honey bee. The Bulletin of Animal Behavior, 5: 1-32
Frisch, K von (1967). The Dance Language and Orientation of Bees. Harvard University Press, Cambridge, Massachusetts
Griffin, SR, Smith ML, and Seeley TD (2012). Do honeybees use the directional information in round dances to find nearby food sources? Animal Behavior, 83:1319-1324
Unhoch, N (1823). Anleitung zur wahren Kenntnis und zweckmäßigsten Behandlung der Bienen nach drey- und dreyßigjähriger genauer Beobachtung und Erfahrung. München
Professor Thomas D Seeley
Professor Thomas D Seeley is the Horace White Professor Emeritus in Biology at Cornell University. His books include ‘The Lives of Bees’, ‘Following the Wild Bees’, and ‘Honeybee Democracy’ (all published by Princeton).
