05-07-2012, 03:06 PM
ZIGBEE TECHNOLOGY
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Figure-Eight-Shaped Waggle Dance of the Honeybee (Apis mellifera). A waggle run oriented 45° to the right of ‘up’ on the vertical comb (A) indicates a food source 45° to the right of the direction of the sun outside the hive (B). The abdomen of the dancer appears blurred because of the rapid motion from side to side.
A waggle dance consists of one to 100 or more circuits, each of which consists of two phases: the waggle phase and the return phase. A worker bee's waggle dance involves running through a small figure-eight pattern: a waggle run (aka waggle phase) followed by a turn to the right to circle back to the starting point (aka return phase), another waggle run, followed by a turn and circle to the left, and so on in a regular alternation between right and left turns after waggle runs. Waggle-dancing bees produce and release twoalkanes, tricosane and pentacosane, and two alkenes, Z-(9)-tricosene and Z-(9)-pentacosene, onto their abdomens and into the air.[4]
The direction and duration of waggle runs are closely correlated with the direction and distance of the patch of flowers being advertised by the dancing bee. Flowers located directly in line with the sun are represented by waggle runs in an upward direction on the vertical combs, and any angle to the right or left of the sun is coded by a corresponding angle to the right or left of the upward direction. The distance between hive and recruitment target is encoded in the duration of the waggle runs.[1] The farther the target, the longer the waggle phase, with a rate of increase of about 75 milliseconds per 100 meters.
Waggle dancing bees that have been in the hive for an extended time adjust the angles of their dances to accommodate the changing direction of the sun. Therefore, bees that follow the waggle run of the dance are still correctly led to the food source even though its angle relative to the sun has changed.
The consumption of ethanol by foraging bees has been shown to reduce waggle dance activity and increase occurrence of the tremble dance.[5]
When scientists placed a dead Apis mellifera bee on flowers they discovered that bees performed far fewer waggle dances upon returning to their nest. This is likely to be because they associate the dead bee with the presence of a predator on the flower and so it is better for other bees to not forage there.[6][7]
Though first decoded by Karl von Frisch, dancing behavior in bees had been observed and described multiple times prior. Around 100 years before Frisch's discovery, Nicholas Unhoch described dancing behavior of bees as being an indulgence “in certain pleasures and jollity”.[3] He did, however, admit ignorance as to purpose of the dancing. 35 years before that, Ernst Spitzner observed bees dancing and interpreted it as transmitting forage resource odors to other nestmates.[3] Even Aristotle, in addition to describingflower constancy behavior, suspected that some form of communication occurred between foragers within a nest:
"On each trip the bee does not fly from a flower of one kind to a flower of another, but flies from one violet, say, to another violet, and never meddles with another flower until it has got back to the hive; on reaching the hive they throw off their load, and each bee on her return is followed by three or four companions. What it is that they gather is hard to see, and how they do it has not been observed".[8]
Jürgen Tautz also writes about it in his book "The Buzz about Bees":
Page 112: Many elements of the communication used to recruit miniswarms to feeding sites are also observed in "true" swarming behavior. Miniswarms of foragers are not placed under the same selection pressure as are true swarms, because the fate of the entire colony is not at stake. A truly swarming colony has to be quickly led to a new home, or it will perish. The behavior used to recruit to food sources possibly developed from the "true" swarming behavior. Tautz,J.: The Buzz about Bees - Biology of a Superorganism (photos by H. R. Heilmann) Springer Heidelberg & Berlin, 2008