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Sound Communication in Honey Bees – Support Material

[1964 Wenner, A.M. Sound communication in honey bees. Sci. Amer. 210:116-124.]

1. EFFECT OF SOUND on bees in a hive is illustrated by the two photographs below made by the author. Bees are normally in constant motion, but they quiet down at the sound of “piping,” a beeping tone produced by workers. The normal motion is shown by the blurred images in the top photograph, which was made at a fifth of a second. When piping was simulated and transmitted to the hive wall by a vibrator, the bees became almost motionless, as shown by bottom photograph, made at the same aperture and speed:

sound-bees-1

sound-bees-2

2. DANCE PATTERN described by the bee’s thorax is not a well-defined figure eight with a distinctive straight run. This suggests that recruits would have difficulty gaining information by following the dance movements alone. To make these pictures Robert C. King and the author put a spot of white paint on the thorax of foragers and then photographed their dances by repetitive flash:

wenner-dance-pattern

3. SOUND SPECTROGRAPH displays frequency against time as shown in this schematic tracing. The amplitude of the signal components is indicated by the darkness of the trace:

wenner-sound-spectograph

4. SPECTROGRAMS analyze the sound produced by forager bees during the dance. Sound trains are produced during the straight run; blank or light areas mark remainder of figure eight. The length of the sound train increases with the distance to the source of nectar:

wenner-sound-bees-4

5. DIRECT CORRELATION is shown between the sound-production time and the distance the bee had just traveled to obtain food. Each point is an average for several dancing bees:

wenner-sound-bees-5

6. DANCING BEES and recruits are seen in this photograph. There are three dancers, or foragers blurred images), heading to the right in a diagonal line starting near the upper left corner. The dancer nearest the left has a recruit on each side, the center one has two recruits on its right and the bee at the right, apparently nearing the end of its straight run, has a recruit at its right rear:

wenner-sound-bees-6

7. FORAGING BEE must transmit to its hivemates information about the distance from the hive to the food source and the angle (a) between the direction of the source and the direction of the sun:

wenner-sound-bees-7

It does a dance on the honeycomb in which its abdomen describes a kind of figure eight:

wenner-sound-bees-7a

The “straight run” (A) of the dance has a duration proportional to the distance to the food, and it is oriented at an angle from the vertical equal to angle a. “Recruit” bees track the dancer’s side with their antennae:

wenner-sound-bees-7b

8. WORKER SOUNDS are shown in these spectrograms. The top tracing illustrates two sounds produced when a hive is disturbed: the sharp burst of a disturbed worker (left), followed by two faint beeps, or worker piping. The middle and bottom tracings show “croaking” and “bipping,” two sounds that have yet to be related to any specific activity:

wenner-sound-bees-8

9. BEE SOUNDS are analyzed by a sound spectrograph. A short segment of a bee sound, recorded in the field, is transferred to the magnetic disk and then repeatedly sampled as the disk rotates with the recording drum. The stylus is a wire from which an electric spark passes to the drum, etching the recording paper. As the stylus rises, its position regulates the filter control so that the frequency analyzer extracts the proper frequency from the total sound, which is broken into a frequency “spectrum” changing with time:

wenner-sound-bees-9

10. QUEEN PIPING includes “quacking” and “tooting.” A queen in her cell produces quacking (left), a series of short pulses with emphasis on several harmonics. Once free in the hive a queen produces tooting (right), which begins with a long wail, has a somewhat higher fundamental frequency and usually emphasizes frequencies not simultaneously emphasized by quacking queens:

wenner-sound-bees-10a

TOOTING was simulated (upper tracing) and played to a caged queen via a vibrator touching the hive (A). It elicited from the queen a response that was picked up by a microphone (B) and analyzed as quacking (lower tracing). When the tooting vibrator was suspended above the queen (C), there was no response, indicating that the queen perceived sound via the hive structure:

wenner-sound-bees-10b

11. RELATION OF WING to sound production was demonstrated by severing most of two wings of a bee (left). Comparison with the sound produced by the intact animal (center) showed that loss of wing area reduced the intensity and changed the harmonics (right):

wenner-sound-bees-11