Can Bees Imitate?

I have been thinking a great deal about the evolution of memes, and wondering in particular about just how big a brain has to be in order to support memetic replication. Humans aren’t the only animals that imitate, after all. Many birds are notorious mimics, and not in the way a viceroy butterfly just happens to resemble a monarch butterfly without ever observing monarchs. The viceroy looks like a monarch because predators avoided eating its ancestors who resembled the very yucky-tasting monarch, and the more close the resemblance, the more likely there’d be uneaten offspring. In contrast, birds genuinely imitate, producing sounds that are actually copies of the sounds the birds hear; if the bird hears a different sound, it produces that sound instead. A parrot might hear a sound, imitate that sound and be heard by another parrot, who in turn might imitate it, and so on; the imitated sound then can replicate as a meme.

But birds have pretty advanced brains in the grand scheme of things, and parrots and crows in particular are remarkably clever animals. What about something much smaller? While pondering this question, I remembered the humble honey bee and its remarkable waggle dance.

When a foraging worker ant finds a good source of food, it can leave a scent trail on the way home so that other workers can quickly find that source and better exploit it. Bees, however, fly through the air, which tends to move around and carry away scent trails, so they need another way of communicating the location of resources to their hive. They do this by way of a special dance they perform when they return home laden with food. The dance indicates a vector: the direction to the food source (relative to the position of the sun) and the distance. Other bees observing this dance then know to fly this far in this direction to find the food and bring back more for the hive.

So what we have here is an ability to communicate. Information is transmitted from one tiny bee brain to another, and manifests itself in behavior to the benefit of the hive. These are really, really tiny brains we’re talking about here, but they still demonstrate the basic mechanical ability to formulate, transmit, and replicate behavior. Bee One does the dance communicating vector A and distance B, and a little while later, after observing this dance, Bee Two does a dance communicating the same vector and distance.

But is this actually memetic? That is, is this truly an instance of imitation?

I don’t know, but I suspect not.  I think that if this happens, it's because Bee Two is reporting its own visit to the same food source, not because it is repeating the first bee's report. I expect the bee brain has two distinct registers for storing these vectors, one for navigating to the food site and one for directing the waggle dance, and these registers are isolated from each other; the navigation register can only be loaded by observing the waggle dance, and the dance register can only be loaded by actually flying back to the hive. I predict that a bee cannot watch another bee perform the dance and then turn around and imitate the same dance for a latecomer who missed the original performance.

Why do I think this? Because there is no evolutionary advantage to imitation here, and indeed considerable disadvantage.

First of all, the waggle dance is analog, not digital, which means that with every replication there is a loss of fidelity. Bees indicate direction relative to the current position of the sun by the angle of the straight run in the middle of the figure eight relative to the vertical. (The dance is performed on a vertical surface, a wall in the hive.)

Now, the angle is accurate enough to get the observer near enough to find the target, but it’s probably not much more precise than that. A bee observing the dance may also misread the direction by a few degrees, and then misjudge a crosswind, but still get within spotting range. Also, since the direction is pegged to the current position of the sun, the bee has to adjust for the passage of time, which it does very well but that’s another area for error to creep in. If a bee were to watch and then imitate the dance, all these distortions would multiply, so that the information content of the dance would soon become unreliable; the hive would waste time and energy sending workers to the wrong place.

Even if the copied dance were perfectly accurate, an imitated dance would allow another problem common to internet chain letters: the propagation of messages long after the information within is outdated. If it were possible for a bee to repeat a second or third hand report, other bees might still be following those directions even though the food source in question had been depleted. It makes much more sense to have each and every performance of the waggle dance be a first-hand report.

I would be delighted to learn that bees are capable of supporting memes. Their brains are big enough to do so, but I predict that as a matter of fact they do not. And that is the falsifiable prediction of my theory. If there are any entomologists or apiologists out there who have actually observed one bee imitate another bee’s waggle dance, I would love to be proven wrong.