Über die durch Licht bedingte «Missweisung» bei den Tänzen im Bienenstock

Summary

Bees are able to indicate direction to their hive comrades by means of a waggling dance of 2 kinds: in the horizontal plane with regard to the sun they point directly towards the goal by a waggling walk using the same angle to the sun as they took in their flight. Inside the dark hive in the vertical honey-comb, they transpose the angle between goal and sun to the field of gravity, whereby the sun's direction is shown by a waggling walk upwards, and the angle to the right or left of the sun's position is given by a dance-direction in the corresponding angle to the right or left of the zenith.

If a piece of blue sky is made visible in an observation hive to the bees which are dancing in orientation by gravity, they recognise the position of the sun by this polarisation sample, and the effort to orientate themselves directly by the sun (as in the horizontal plane) comes into conflict with the orientation by gravity. The result is a dance direction which corresponds remarkably well with the halving of the angle between what the dance direction should have been by gravity and what it should have been by light orientation (Figure 1). This is also true when the bee is orientating itself by polarised sky light over its back, while the sun is at the other side of the honey-comb under its front (Figure 2), a situation which does not occur during flight but which is important for its dance in the swarm. The bees receiving the information compensate the deviation of the angle determined by light, and fly to the right goal.

As the sun itself, as well as the piece of blue sky, was made visible to the dancers, its influence dominated and they orientated themselves by its light (Figure 3).