Waggle dance

The language of dance is one of the essential forms of communication of honey bees. By dancing several types of information about food sources ( costume sources) will be taught.

Starting position

Approximately 5% of the flying bees are so-called scouts. Their task is to look in new areas for new food sources. This interconnected with numerous dangers Part accept only those bees that are already relatively at the end of their life expectancy and their loss to the hive is not a big risk more. The majority of foragers remains the case that a new food source is found, their rapid processing is necessary, waiting in the floor.

Was such a scout with their search is successful, they are in returning their yield, for example, the collected nectar Stock comrades. Did this a sufficient quality and there is demand in the floor, the collector of these Vorkosterbienen is excited by energetic sensor contacts to notify the locality of their prey the waiting foragers, which is the case in approximately 10% of the returning foragers.

This is done by so-called dances, in which the bees striking and characteristic patterns of movement, which gave its name to the dances, perform in the floor.

Even when the swarms audition plays a crucial role in finding and selecting a suitable nest site new. When a bee colony wants to reproduce, creating a swarm of bees.

Information content

With these dances the waiting foragers of the dancer be notified four different information about the source of raw materials mainly:

• To collect basic fact that resources were found in a sufficient amount, as well as the prompt also there
• Type of raw material found (by smell and taste)
• Yield and quality of the source ( by intensity of the dance )
• Seen from the location of the discovery site stick out (by distance and direction indication, only the waggle dance )

The dances are the same for all data collected by foragers raw materials except for minor differences, most often, such a motion, however, to a food source (eg, nectar, pollen, honeydew or water) down.

Dance forms

Depending on the distance of the feed or raw material sources, a Fund is expressed by various dances. For sources in the surrounding floor area ( to 100 m) mainly takes the round dance application for all the sources further away the bees use the waggle dance. The dance is always only one (but fairly accurate ) target area to where the bees once they have achieved it mainly based on odors.

Round dance

The round dance, the simpler and historically probably older, but also less precise form of the two primary types of dance dar. The location of the feed is not directly specified, the foragers learn only that the source is located in the near vicinity of the building.

In the round dance the bee for up to 3 minutes running in a small circle around (radius 1-2 cm) and thereby changing after one complete revolution about its rotational direction. So you attract the attention of other foragers (usually 2-3 individuals ), which now remain with their antennae as close to the abdomen of the dancer and follow their rapid movements. Through close contact sensor, the trailing foragers perceive the smell of visited plant. Occasionally, the dancer chokes it out additional drops of nectar, which lick the dance followers, and thus learn the taste.

After the end of the dance, the dance followers determined to make the search for the lining, where they focus mainly on the basis of the information communicated to them the fragrance.

Before the scout breaks himself for re- search of a new place, they repeated their dance even at two or three other places in the floor where the information is also passed to waiting animals. Return after flying back to the source, it implies the locality in the same way as the original discoverer, as long as until the feed locality fully exploited or no need for this.

Waggle dance

If the food or resource sources further from the floor removed, the type of information transfer in the return of the flying bees changes.

In order to ensure a fast as possible and thus efficient retrieval of a place in up to several kilometers measured catchment area of the building, whose spatial position must be much more precise than specified only through its rough distance. This is done by the so-called waggle dance.

Formation

The bee research is now assumed that the waggle dance initially not as now found application primarily in search of food, but first when swarming (propagation of a people ). The food sources were probably given exclusively through the round dance. When swarming possible new nesting sites on the so-called bee cluster are marked with a waggle dance, but unlike the foraging takes place in the horizontal. Since in this case is not only an animal's life, but of the whole people is at stake, and beyond a nesting site has no fragrance or other easily observable characteristics, it is only logical that the location information must be done very carefully. Presumably, this dance has then been established due to the advantages of this precise specification system also in search of food, but being totally ignored without the lap dance.

Expiration

As with the round dance is first decided by the Vorkosterinnen whether the bee returned home to tell her find another. If this is the case, the latter begins - usually about in the mid - floor with their characteristic movements in order to spread the information. This dance consists of the following runout and the waggle. When the bee waggle runs first with vigorous lateral vibration of the abdomen ( fishtailing ) from just a few centimeters. Then she returns in the radial run in an arc to the starting point of the tail-wagging back. From there, the waggling begins again, again followed by the run-out, but now in the opposite direction. Here, the dancer will also be developed as the round dance of three to four collectors, which during which arrange themselves so that they can register the waggling dancer well with their antennae.

The decisive factors are the dancer in pulses emitted sounds, without which the other foragers would not follow. These signals have a frequency of 240-260 Hz and are emitted with the enormous volume of approximately 110 dB during the Schwänzellaufs. However, this noise level is only a few centimeters wide audible for bees on the same honeycomb, because most of the sound is sent from the wings vertically instead of horizontally, and thus a bell sound is created, in which the volume decreases with the cube of the side. This sound is produced by the bee with its flight muscles, which it is in a kind of idle. Therefore, the sound frequency corresponds to the average wing beat frequency. Western honey bees respond with their hearing to address attention to the so-called particle velocity, ( oscillation of air molecules ) while other animals or humans, for example, the sound pressure ( pressure fluctuations of the sound medium ). Therefore, the number and the sequence of sound pulses is more important than its length or frequency. The sequence of acoustic pulses is not dependent on the frequency of the fishtailing.

In addition to the sound pulses in the air vibrations with the same frequency on the wax of the honeycomb are passed during the waggle also. To some extent, also spoke of a place Schwänzelstand - run, because the insect in this case most of the time has a very stable contact with the honeycomb.

Location

The site will specify two for bees easily measurable attributes. On the one seen the distance to the floor and on the other the direction to the source of the hive from ( polar coordinates).

The distance is determined by the time required for the flight and the energy experienced during the flight optical flow. The optical flow denotes the frequency of abrupt changes in the appearance of the environment (eg transition between pasture and forest). The energy consumption is measured by the animals by the absorbed during the flight (spent ) food using receptors in the honey stomach. From these values, the distance is determined and this translated by her in returning to a specific tempo dance of the bee.

The more turns makes the animal per unit of time, the closer is the feed source. With increasing distance consequently reduces the dance speed.

The direction of the feed location is always specified relative to the Sun. This also works in cloudy weather, the sun's position is perceived by the animals on the basis of the polarization direction of the light in the sky even through clouds. In the rare, but simpler case that the bees dancing on a horizontal surface, the waggle dance pointing directly toward the food source. The angle of the sun can be taken from the waiting there foragers immediately.

In the search for raw materials but dances are a rarity on a horizontal surface. Normally, the information transfer takes place in the vertical plane in the dark of the building. Here is a directed straight up waggling represents a source in the direction of the sun, a rotation of the barrel at an angle α stands for a flight to α against the sun. Where exactly in the floor above, recognize the animals on the basis of gravity and the geomagnetic field. Even with an artificial slope of the stick to the horizontal so that the animals can provide accurate information to about 15 °.

The directions of the dances always refer to the horizontal. Information about the level at which a source is located, are not transmitted from animals because the main food suppliers such as flowers always occur near the ground. Obstructs an obstacle such as a mountain ridge direct path to a food source, enter the insect rather than flown their way to, but transmit the direct toward this place, which is a huge cognitive performance. The following bees fly over the obstacle first correspondingly straightforward. Once they know the area, they look even better or easier way.

Accuracy

In stages and subjects experiments it was shown that the vast majority of collectors is also looking at the specified location. The variances arise in part by the fact that each bee the information supplied to it interpreted individually and on the other by external factors. Thus are another rewarding food source, for example, even before the specified location.

Recent research shows that the precision of the signal transmission in the waggle dance by sleep deprivation and fatigue so by the bees may be affected.

Research

The bee dance was described by Aristotle. Getting further investigations were carried out in 1920 until much later by the ethologist Karl von Frisch. During this time it was not known fresh that the waggle dance provides information on the direction and distance of a food source. He was of the opinion that the waggle dance only of pollen foragers and the round dance performs only be of nectar foragers. After fresh, the main task of dance in the transmission of food odor and the announcement of a productive food source.

Only a change of the experimental setup his feeding experiments 20 years later enabled him to decode the waggle dance. In the years 1944 and 1945, started fresh, feed at a distance of more than 100 m to offer, what with all collectors, whether nectar or pollen collector, tail-wagging caused. In 1973 he received the Nobel Prize especially for the decryption of the dance. Meanwhile, it also managed to imitate the bee dance with a robot and then send off the bees in a certain direction.

Recent research could identify individual substances from the group consisting of alkanes ( tricosane and pentacosane ) and alkenes ( tricosene and Pentacosen ) as semiochemicals ( chemical messengers ) by using gas chromatography -mass spectrometry.

Earlier it was believed that a worker who had to travel a long distance, on arrival is exhausted, as a bee, the food has been found in the vicinity, which is why the dance is less intensively carried forward.

This information is now obsolete, according to studies by Prof. Tautz (University of Würzburg). Then register the bees, the movement pattern of the passing in flight pictures. The flight over monotonous lines (fields ) is interpreted as shorter than the flight eg between closely spaced trees.

Many insect species are able to orient themselves on the sun and maintain a certain direction by moving in a certain angle to the sun. In beetles could be demonstrated that they orient themselves in the absence of light on the vertical. For this purpose they were put on a tiltable horizontal surface. When running in a certain direction, the light is turned off while the substrate is tilted vertically. The beetles changed their direction and continued to run at the same angle to the vertical, which they had previously adhered to the light source.

The ability to form a connection between the sun and the angle to the vertical, so seems to be more common among them. To investigate whether this correlation also in bees, a light source was installed in the normally dark hive. Then, the direction of the waggle dance is specified relative to the light source. When a returning worker bee 's eyes glued with shellac, so that they could not see the light, they oriented to the vertical. All other bee interpreted the dance but relative to the light source - and flew in the wrong direction.

Presumably, the waggle dance was originally listed before the floor and given the actual direction to the sun. Later he was transferred to the inside of the stick and it exploited the already existing ability to reorient.

The question of uniqueness and significance of the waggle dance is the subject of ongoing investigations.

The inaccuracy of the dances also documented a new work by Tanner and Visscher.

Due to the polarization of light, which can be perceived by the human eye ( Haidinger - tufts ), it is possible to identify the angle of the bee and audition so. The necessary sensory cells lie in the eye of the bee. It is trimmed to the maximum of the polarization, so that cell is also energized at a maximum. So the bee can memorize the coordinates. The temporal shift which also attracts a shift of the polarization after himself, does the bee with her ​​good term memory offset. For this realization in 1973 of the Nobel Prize to Karl von Frisch was awarded.