Sex on Six Legs_ Lessons on Life, Love, and Language From the Insect World - Marlene Zuk [100]
Beekman and her colleagues study dance language in the red dwarf bee of southeast Asia, which is closely related to the honeybee but nests in the open, making a single comb that is suspended from a shaded branch, rather like a wasp nest. This nesting habit is thought to be more like the ancestral state, with the elaborate cavity nests of the honeybees and several other species being more recently evolved. Dwarf bees still dance, and like honeybees, they do so both when they are selecting a new nest site and when they are feeding. But giving directions to a new nest site on a branch out in the open poses a much different problem than telling the rest of the colony how to find a small entrance hole to a cavity, such as the honeybees use. It's like the difference between telling someone to head north on State Street until he sees a big pink building—"you can't miss it"—versus giving explicit directions to a door on the third floor, east wing, of that building. On the other hand, a flower patch is a flower patch, and directions don't need to be all that precise when a worker is dancing to indicate where her nest mates can find food.
By videotaping dances of the dwarf bees, Beekman and her colleagues found that the dances used for both food and nest site directions were equally imprecise. Honeybees, in contrast, are far sloppier when they dance to show the other workers where food is than when they are directing them to a new home. The scientists believe that the dance evolved as a way to convey information about the new nest site, and that its use to indicate food sources came later.
If more than one species of bee uses symbolic language, can they understand each other? In a paper titled "East Learns from West," Songkun Su from Zheijiang University in China and co-workers showed that Asian honeybees, which are a different species than the European honeybees commonly found in Europe and the species that has been introduced to North America, can follow directions given by their European counterparts. Su and colleagues painstakingly constructed colonies containing a queen of one species and workers of the other, a daunting task because the specific odors of each colony usually mean the different species detect and kill any outsiders. Ordinarily the dances from the two bee species differ in what might be called dialect, with variations in the duration of the waggle portion of the dance. Su demonstrated that the two species could follow each other's directions, which means that the bees must learn some elements of the dance language.
Bees, Chimps, and Symbols
DESPITE the great interest in bee communication and the ever-greater elucidation of the dance, as Wenner points out, no one has ever been able to use the information to direct bees to particular crops that need pollinating or to sources of nectar that would be preferred by humans for honey production. So what is the significance of the bee dance language?
As I have mentioned before, we seem almost obsessed with setting out criteria for membership in a club that only we can enter; humans are the only species to use tools, for example, or to routinely kill members of our own species without using them for food. Both of these turn out to be unwarranted—chimpanzees, crows, and several other animals use tools, and fig wasps, among other species, routinely slaughter their own. One can detect a certain desperation in resorting to homicidal violence as a badge of distinction, but the effort continues. And language, with its slang and poetry, has always remained a prime candidate.
The problem is that many if not most other animals communicate, too, and they communicate in often complex and sophisticated ways. As Alison Wray put it in a book titled Language Origins, "Pinning down precisely what it is that makes human language special has never been so difficult.