I’m currently reading Fruitless Fall: The Collapse of the Honey Bee and the Coming Agricultural Crisis by Rowan Jacobsen. In the first two chapters, he does a wonderful job of outlining the history of honey bees in America, a brief introduction of their importance, as well as an overview of the inner workings of a hive. It includes a summary of the average worker bee’s life, but it reads more like a short story than a biology textbook. As the book proceeds, Jacobsen covers current research (well the book was written in 2008, current at the time) regarding varroa, Colony Collapse, commercial pollination problems, pesticides, and much more honey bee afflictions. I’m enjoying the book so far as it read quickly and easily and is filled with information, but not in a way that bogs the reader down.
In the first chapter, Jacobsen provides a nice description of the waggle dance. Honey bee communication is fascinating to me for several reasons. First, the inside of a hive is completely pitch dark, so that adds a certain difficulty right off the bat. Next, hives are made up of tens of thousands of bees and the colony works together as one highly efficient super organism. You know how smart humans are, right? Put 10 of them in a room (let among 10,000) and ask them to make a decision. I can guarantee what you won’t have, is a highly-efficient body that works as one!
Specifically, bees need a form of communication so that they can tell the others if they’ve found an incredible nectar source. Similarly, they use this communication to indicate water and pollen, as well. There is a section of comb just inside the entrance that Jacobsen calls the “dance floor.” This is where returned foragers perform the waggle dance. The waggle dance is a movement made by foragers that communicates distance and direction of a nectar source. It is performed by the bee wiggling it’s butt around. The angle of the bee’s dance indicates direction (using the sun as a reference point) and the duration of the dance indicates distance to the source. The number of dance repetitions, indicates source quality.
The purpose of the waggle dance it to recruit more foragers to visit the source. The initial dancer will repeat the dance and other foragers (who wait around the “dance floor” for just such an occasion) mimic the dance (conga line-style) until they know it for sure. Researchers have found that bees will perform the dance repeatedly if the source is incredibly good. A blossoming apple tree, for example, will get more dance repetitions than a small tuft of clover.
Jacobsen likens this to humans eating out at a new restaurant. If the restaurant is particularly good, you may tell 15 friends, post about it on Facebook, and even write a comment on Yelp. If the restaurant is not-so-good, you may tell one friend (or not any) and certainly not with any sort of enthusiasm. Likewise, bees perform a waggle dance with varying levels of excitability as well.
Just as there are bees waiting at the hive entrance, just dying to become foragers, there are also bees hanging around waiting to receive the fruits of the foraging. When bees find nectar, they suck as much as they can into their honey sac. When they return to the hive, they “hand off” the nectar to a waiting receiver, who then takes it into the hive. The waggle dance, then, calls for more foragers while a different (but similar) “tremble dance” is a call for more receivers. So if a forager does find the mother-load, the call for more receivers might go out as nectar-laden workers return one after another to the hive.
Below is a very cool vide from BBC that shows an example of a waggle dance and also gives you a quick explanation of the navigational abilities of the honey bee.
Here’s another short explanation, with some video of an actual waggle dance: