Difficult choices

Honeybees are known for their collective capacity to make good choices. For example, when faced with a decision about whether to forage on flowers yielding copious amounts of nectar vs. those that are weak nectar producers, colonies learn quickly to focus on the more productive resource.

But what happens when their decisions are less clear-cut, and their choices more difficult?

A fascinating new study out of Australia shows that, when faced with insufficient information to make an informed choice, honeybees opt out of making any decision.

The researchers used an experimental model first developed with dolphins, that rewards an animal for a good choice, punishes for a bad one, but provides a third option where the test animal can decide not to choose at all. In the honeybee experiment, the authors trained bees to targets associated with either a sugar reward or a foul-tasting quinine punishment.

Bees trained easily when the targets were distinctly shaped or clearly located relative to the reward/punishment, soon learning to imbibe the sugar and ignore the quinine. However, when targets were only slightly different in shape or location, and difficult to tell apart, bees soon gave up sampling either one, opting out of making any decision. That is, uncertainty led to withdrawal of the bees’ interest in making any choice, at least until the options clarified.

Swarms have a similar opting-out mechanism when faced with more than one choice for a new nest site. A swarm that’s issued from a hive and is suspended from a tree branch or other overhang must find a new nest quickly if it is to survive. The swarm sends out worker bees to search, return and do a dance communicating the distance, direction and quality of potential sites, attracting additional scouts to examine prospective cavities.

A number of sites are scouted, but eventually the swarm reaches agreement and dances to only one superior site before lifting off, all the bees flying to the new nest together. Occasionally, though, two sites are equally valued, and the swarm lifts, splits, each half flies 20 to 30 feet in one of the two nest directions and then the bees in both groups return to the overhang, recognizing that their choice isn’t as clear as it needs to be.

Additional scouting and dance conversation ensues until the best choice clarifies. Just as in the reward/punishment experiment, swarms opt out of making a decision when faced with uncertainty.

There’s a lesson to ponder here for we humans as well. When choices are not obvious and we are faced with difficult decisions around highly nuanced issues, perhaps we would benefit by waiting.

For example, regulators often approve pesticides with insufficient research prior to licensing. I wish there had been more extensive information on neonicitinoid impact on bees before these controversial chemicals became the globe’s most ubiquitous agricultural pesticide.

And bees would be in much better shape today if field trials about the impacts of genetically modified, herbicide tolerant crops had asked whether these crops might be too efficient. While not directly toxic to bees, they are harmful by eliminating the diverse forage that honeybees and wild bees depend on for adequate nutrition.

It’s the precautionary principle: if there is a suspected risk of harm, slow down implementation of new technology until safety is proven.

Bees get it; perhaps we should too.

The decision-making study was published in the Proceeding of the U.S. National Academy of Sciences (2013, 110:19155-19159, Clint J. Perry and Andrew B. Barron, “Honey bees selectively avoid difficult choices”), available on the web at http://www.pnas.org/content/110/47/19155.full. For more on swarm choice, see Tom Seeley’s excellent book Honeybee Democracy (2010, Princeton University Press)