Sex on Six Legs_ Lessons on Life, Love, and Language From the Insect World - Marlene Zuk [93]
Kirk, Seeley, and Kevin Passino of Ohio State University made this discovery using bee colonies on Appledore Island off the coast of Maine, where Cornell has a research facility. The island was handy because it has almost no trees that could serve as natural nests, which means the scientists could provide all the potential homes for the colonies they brought there.
The scientists gave different swarms of bees on opposite sides of the island either just one nest box into which they could relocate, or five similar boxes set close together. If the bees required a quorum of dancers, the dilemma of five equivalent alternatives should delay the formation of the quorum and, hence, delay the swarm movement itself, but the rest of the decision-making process would be the same in the two cases. As predicted, the bees took an average of 442 minutes to arrive at a decision when they were spoiled for choice, as it were, compared with just 196 minutes when one box was available. "Group intelligence," the researchers concluded, "is a product of disagreement and contest." Whether that constitutes more optimism than Nietzsche is perhaps a matter of debate.
Kirk and Tom Seeley also determined that the bees dance differently depending on the quality of the site they have discovered; scouts spent equal amounts of time inspecting two potential sites that were offered, but performed more circuits of their dance back at the swarm for the better location. The bees also avoid getting drawn into agonizing fruitlessly over a poor candidate by the rapid decrease in sequential visits to a lower-quality site, so that they are able to ruthlessly reject a loser instead of second-guessing themselves, something more humans would probably do well to emulate.
How the bees assess the presence of enough scouts to constitute a quorum is still not well understood. The swarm does not always arrive at a unanimous decision; occasionally one will split at takeoff, and even when dissention is not so drastic, a few divergent dancers will still be rooting for their own selection up until the very last minute. Until very recently, scientists likewise could not understand how the group of bees could all get up and move in synchrony after the winning site was selected. The scouts produce a kind of rallying cry, called piping, that seems to energize the swarm to warm up before they take off in unison.
Some work by Seeley and Clare Rittschof of the University of Florida suggests that the scout bees work the crowd by moving among the more languid members of the group, making a stereotyped set of motions accompanied by sounds, called a buzz-run. The buzz-run seems to encourage any laggards to move their wings as well, which in turn ensures that everyone's wing muscles are sufficiently warmed up for flight. Because they are cold-blooded like other insects, bees need to reach a certain temperature before they can fly, and they do so by revving their muscles like diminutive engines. Rittschof and Seeley then proposed that the scouts act like swarm thermometers to gauge the temperature of the mass of bees and trigger its synchronized takeoff when everyone is ready.
Even after takeoff, the synchronicity of the swarm is amazing. Although the scouts have done their advertisement and the decision has been made, less than 5 percent of the bees in the swarm have actually been to the site themselves and, hence, don't know exactly where to go. Yet all of the ten thousand or more end up in the right place, often miles away. Another publication with Seeley as the bee expert, this time with engineer Kevin Schultz from the Ohio State University as a collaborator, gave the solution to this problem as well. Using high-definition films of the swarms on Appledore Island, the researchers