[Tom] Seeley and [Susannah] Buhrman used swarms in which every
individual bee was marked with a number, and they videotaped the
entire process. "What's marvellous about bees is that the decision
making is quite transparent", says Seeley. From the videotape, they
could see which bees danced for which site, and monitor the
popularity of each site, relative to the site that the swarm
eventually flew to.

As they expected, at first there are bees dancing for different
sites. Then one site grows in popularity. More and more bees dance
for that site, until eventually all the scouts are dancing for the
same site. As soon as that happens, the swarm flies. To understand
how the bees always choose the best site, you need to track the
behaviour of individual scouts.

By painstakingly observing dozens of hours of videotape, the
scientists first watched bees who began dancing for a site that was
not eventually chosen. They discovered that these bees do not later
change their minds and convert to the best site. They simply stop
dancing.

But the real surprise came when they looked at bees who began dancing
for the chosen site. Many of these bees also stopped dancing before a
decision was made. So the consensus is not reached because the bees
who have found the best site never shut up. Instead, a scout bee is
programmed to do its dance for about a day and then to stop. "The
decision is made by a process of differential recruitment", says
Seeley. More and more bees visit the better site, because they have
seen other bees dancing so hard for it, until all the bees left
dancing are just dancing for one site. "This is a very friendly way
of reaching agreement", Seeley adds. "The scout bees do not compete
aggressively with each other".

As humans, we are not very good at making group decisions. We
wrangle, debate, argue, and persuade, but we usually end up resorting
to a voting system, in which some people get what they want and
others have to go along with it.

"Bees gain a consensus without any individual changing its mind or
losing", says Seeley. "This is a remarkable system to emerge from
some very small-brained animals."

http://www.bbsrc.ac.uk/news/features/00jan/00_01_bees.html


Seeley writes:

We found that when a scout bee returns to the swarm cluster and
advertises a potential nest site with a waggle dance, she tunes the
strength of her dance in relation to the quality of her site: the
better the site, the stronger the dance. A dancing bee tunes her
dance strength by adjusting the number of waggle-runs/dance, and she
adjusts the number of waggle-runs/dance by changing both the duration
and the rate of her waggle-run production. Moreover, we found that a
dancing bee changes the rate of her waggle-run production by changing
the mean duration of the return-phase portion of her dance circuits.
Differences in return-phase duration underlie the impression that
dances differ in liveliness.

http://link.springer-ny.com/link/service/journals/00265/contents/00/00299/s002650000299ch002.html
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Peter Borst <[log in to unmask]>