What information does the waggle dance encode?
Short answerTrueEmerging research
Two things: direction, as the angle of the straight run away from vertical, which equals the angle of the target away from the sun's bearing; and distance, as the duration of the waggling portion. Dance vigour adds a third piece of information — how good the source is — which is how the colony weighs one patch against another.
The code
- Direction: straight up the comb means fly towards the sun; sixty degrees left of vertical means sixty degrees left of the sun's bearing.
- Distance: roughly a second of waggling per kilometre, with the exact calibration differing between species and subspecies.
- Quality: a richer source produces a longer, livelier dance with more circuits, recruiting more followers.
- Time correction: the sun moves while a bee is inside, and a dancer adjusts the angle to compensate without being able to see the sky.
The substitution of gravity for the sun is the part that startled everybody. Inside a dark cavity there is nothing to point at, so the dancer transposes a solar bearing onto a gravitational one. Species that dance on a horizontal surface in daylight simply point at the target, which is almost certainly the ancestral form.
Where the distance comes from
A dancer is reporting a distance she has measured, and she measures it from optic flow — how much the image of the ground slid past on the outward flight. Bees flown through a narrow patterned tunnel experience far more image motion than the real distance warrants, and dance a much longer distance than they flew.
Sources
- The Dance Language and Orientation of Bees — Harvard University Press (1967) · Monograph
- Honeybee navigation: nature and calibration of the 'odometer' — Science (2000) · Peer-reviewed article
- The flight paths of honeybees recruited by the waggle dance — Nature (2005) · Peer-reviewed article
How sources are selected and weighted is set out in the sources and evidence policy.