The Dance
More than half a century ago, Karl von Frisch rocked the world
of behavioral biology with his conclusion that the honeybees (Apis mellifera) can actually communicate the distance
to and direction of valuable food sources through an elaborate “waggle dance.”
In what later led to his receipt of the Nobel Prize in Physiology or Medicine,
von Frisch determined that bees recruited by this dance used the information
encoded in it to guide them directly to the remote location of the resource.
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| Bee dance |
In the typical waggle
dance, a foraging worker bee who has found by a rich food source returns to the
hive, is greeted by other bees, and commences dancing on the vertical comb
surface within the dark nest (in other species of bee, like Apis florea, the dance is performed on a horizontal
surface in direct view of the sun and/or other landmarks). She dances in a
figure-eight pattern, alternating “waggle runs,” during which she vigorously
waggles her body from side to side in a pendulum motion at about 13 times per
second as she moves forward in a straight line, with return phases in which she
circles back to the approximate starting point of the previous waggle run,
alternatingly between clockwise and counter-clockwise returns. Here’s a video
of a bee doing the waggle dance:
As the video indicates, the honeybee’s dance encodes key
information about the resource. For instance, as she performs waggle runs on
the vertical comb surface, her average body angle with respect to gravity
corresponds to the direction of the food source relative to the current
position of the sun (the sun’s azimuth).
Accordingly, if the food source lies in the exact direction of the sun, she will waggle straight upwards; if the food lies, say, 30 degrees to the right of the imaginary line to the sun, she will angle upwards 30 degrees to the right of vertical. Also, the duration of her waggling runs is directly linked to the flight distance from the hive to the food source, with (for many bee subspecies) every extra 75 milliseconds of waggling adding roughly another 100 meters to the distance. Further, the more attractive the destination, the longer and more vigorously she dances, and the more quickly she returns for the start of each waggle run. Depending on the richness of the food source, she may perform up to 100 waggle runs in a single dance.
Accordingly, if the food source lies in the exact direction of the sun, she will waggle straight upwards; if the food lies, say, 30 degrees to the right of the imaginary line to the sun, she will angle upwards 30 degrees to the right of vertical. Also, the duration of her waggling runs is directly linked to the flight distance from the hive to the food source, with (for many bee subspecies) every extra 75 milliseconds of waggling adding roughly another 100 meters to the distance. Further, the more attractive the destination, the longer and more vigorously she dances, and the more quickly she returns for the start of each waggle run. Depending on the richness of the food source, she may perform up to 100 waggle runs in a single dance.
Cognitive Complexity
It seems, then, that honeybees have evolved an extraordinary
complex form of symbolic communication about distant resources, one that is
beyond the capabilities of virtually every other species except for humans. Not
bad for an insect.
The cognitive tasks implicated by the waggle dance are not
insignificant: the dancer must remember the location and characteristics of a
specific site she has seen on her foraging trips, and translate this
information into the appropriate dance characteristics. She must also remember
and take into account the position of the sun, and update that position as the
sun moves (the ability to compensate for the sun’s movement by memory has been
documented by researchers observing dances over several hours of overcast
weather, when there are no celestial cues to be seen). The observing bees must
“read” the dance, translate their sensory input into a resource location, and
then find the resource, navigating as necessary around hills, houses and other
obstacles.
In fact, the feat is so stunning that von Frisch’s findings were
initially met with significant skepticism and controversy.1 At this point, the
controversy has essentially been settled, with scientists recognizing that
there is compelling evidence that honeybees really do communicate and act on
the information encoded in the waggle dance, even though uncertainty remains
regarding exactly which signals (tactile, odor, vibrations, air flows, etc.)
the observing bees use to translate the dance into actionable information
regarding the resource location.2
Is the Waggle Dance a “Language”?
So, the waggle dance is an extremely complex communication
system, but is it a language?
Eileen Crist, Associate Professor in Science and Technology in
Society at Virginia Tech, makes a rather compelling case that the waggle dance
embodies many of the attributes of a true language.3 After noting that
the waggle dance is always performed in front of an audience and is clearly
communicative in nature, she describes some of the principal features that
support its being characterized as a language:
1. Rule-Governed. If a communication
system is to be considered linguistic in nature, it generally must be based on
a set of rules that are structured and used with regularity. This is the case
with the waggle dance: the dance is always performed in a designated place
within the hive, it is never done unless an audience is present, and it always
follows a standard template for conveying direction, distance, and
desirability. While the general rule is that the waggle dance is to be used to
inform other bees about sources of nectar, when the colony has a special
requirement (e.g., locating water when the hive is overheating or finding a new
home when part of the colony must relocate) then the rules dictate that the
dance purpose switches to this pressing need. Also, the general rule is that
foragers dance about rich, reliable and near resources, but in times of need
the “dance threshold” for less desirable resources is lowered.
2. Complexity. A key dimension of
a true language is its complexity, as it is unlikely that a communication
system based on just a few rules will qualify as a language. The bee dance
rules are not only extremely intricate, but they are applied in a versatile and
complex fashion to respond to differing environmental factors and hive
requirements.
3. Stability and Dynamism. A core feature of
human language is that a relatively fixed and stable syntax enables the dynamic
generation of an indefinite number of new sentences. Similarly, while the
waggle dance always takes the same recognizable forms, it “accommodates
different purposes, shifting circumstances, urgent needs, and unprecedented
events; while structurally identical every time, it is also contextually
flexible.”
4. Symbolic. By itself, the symbolic
nature of the waggle dance has led to its being called a language. The dance
symbolically represents conditions existing in the real world, actually
enabling human researchers to “read” the information encoded in the dance to
find specific honeybee food sources and even to design experiments about
honeybee foraging behavior.
5. Performative. According to linguistic
theory and as first articulated by John Austin, languages not only describe the
world, they also include what he called “performative” utterances, which are
used to carry out actions.4 Not only is the
waggle dance symbolically descriptive, but it has performative force in the
sense that it elicits action from the bees who watch it (as Crist notes, the
performative nature of the waggle dance is implicit in the way in which
scientists “routinely deploy a vocabulary of announcing, reporting, summoning,
recruiting, soliciting, inviting, commanding, and guiding” in describing it).
James Gould, Professor of Ecology and Evolutionary Biology at
Princeton University, summarized both the controversy over the issue and the
nature of honeybee dance communication as follows:
Some of the resistance to the idea that honey bees possess a
symbolic language seems to have arisen from a conviction that “lower” animals,
and insects in particular, are too small and phylogenetically remote to be capable
of “complex” behavior. There is perhaps a feeling of incongruity in that the
honey bee language is symbolic and abstract, and, in terms of information
capacity at least, second only to human language.5
Gould estimates that the waggle dance is capable of
communicating at least 40 million unique messages (“sentences”), more than 10
times as many as any other animal except for man.6
Not surprisingly, not everyone agrees that the waggle dance
constitutes a true language. For example, Stephen Anderson, Professor of
Linguistics at Yale University, acknowledges that honeybee dance communication
is elaborate and cognitively rich, but concludes that it is unlike human
natural language in that, for example, it is genetically fixed rather than
learned through environmental interactions, it lacks a syntax in which the
order of the communicative elements (words or actions) impacts meaning, and
there is a close correspondence between the structure of the dance signals and
the nature information to be conveyed (e.g., orientation of the waggle run and
the direction to the resource).7
Some bees are better at the dance than others...
To Bee or Not to Bee
In the end, there will probably always be debate and
disagreement over whether the waggle dance is a true language. Clearly, the
waggle dance and human language are vastly different communication systems, and
how we label the waggle dance in human terms may be missing the point. From the
honeybee standpoint, the dance serves its purposes and contains all of the
communicative nuances that the bees need within their environment. Maybe, the
real point is that we should sit back and appreciate the fact that the
honeybee, a small insect with tiny brain, has been able to evolve a system of
communications that is so sophisticated that it has challenged human linguists
to wrestle with the question of what distinguishes a true language and whether
human language is really so unique.
Anyhow, time to stop droning on and sign off!
_____
1See, e.g., Gould, J. (1975). Honey bee recruitment: the dance-language
controversy Science, 189 (4204), 685-693 DOI: 10.1126/science.1154023.
2See, e.g., Landgraf, T., Rojas, R., Nguyen, H., Kriegel, F., & Stettin,
K. (2011). Analysis of the Waggle Dance Motion of Honeybees for the Design of a
Biomimetic Honeybee Robot PLoS ONE, 6 (8) DOI: 10.1371/journal.pone.0021354; Gil, M., & De Marco, R. (2010). Decoding information in the
honeybee dance: revisiting the tactile hypothesis Animal Behaviour, 80 (5),
887-894 DOI: 10.1016/j.anbehav.2010.08.012.
3Crist, E. (2004). Can an Insect
Speak?: The Case of the Honeybee Dance Language Social Studies of
Science, 34 (1), 7-43 DOI: 10.1177/0306312704040611.
4Hymes, D. (1965). : How to Do
Things with Words . John L. Austin. American Anthropologist, 67 (2),
587-588 DOI: 10.1525/aa.1965.67.2.02a00970.
5Gould, J. L. Ibid. at 692.
6Gould, J. L. Ibid. at note 37.
7Anderson, S. R. 2004. Doctor Dolittle’s delusion: Animals and the uniqueness of human
language. New Haven, Conn.: Yale University Press. ISBN-13:
978-0300115253.
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