Biological Inspiration - Bees

1
Biological Inspiration - Bees

• Introduction
• The Dance Language and Orientation of Bees,
  Karl von Frisch
• More Recent Developments
• References

Jun Goo, Autonomous Multirobot Systems, October
12, 1999
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Introduction

• Why do people study bees?

3
Economic Importance in Agriculture

• Economic reasons they play a critical role in
  U.S. agriculture
• Value of crops requiring bee pollination
  estimated to be around 24 billion each year
• Commercial bee pollination valued around 10
  billion annually
• USDA pays for research aimed at the improvement
  of honey bee pollination of fruit and seed crops
  and ecologically important plant species

United States Department of Agriculture Agricultur
al Research Service
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Interesting focus of research

• Honey bees pose an interesting puzzle to
  biologists because they exhibit astonishing
  adaptive flexibility in their responses to
  features of their environment, and yet have
  exceedingly small nervous systems with which to
  handle the relevant sensory information. The
  juxtaposition of behavioral complexity and neural
  simplicity raises the hope of insights into the
  design features by which nervous systems can
  efficiently encode and store information about
  the outside world, and into evolutionary
  principles by which such behavioral abilities
  could have arisen.

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Why do people study bees?

• Communication How do they inform other bees of
  food sources which can be up to more than 10 km
  away?
• RecognitionHow are they able to distinguish
  nestmates from other bees? Or landmarks?
• OrientationHow do they know where they are or
  where they are going?
• Social behavior, division of labor
• Aerodynamics, neurobiology, chemistry, genetics,
  evolutionary biology, ...

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The Dance Language and Orientation of BeesKarl
von Frisch (1967)

• For many centuries, naturalists had observed that
  honeybees were able to tell their nestmates about
  discoveries they make beyond the hive but the
  system of communication that the insects used
  remained a mystery
• 1940s, Von Frisch (University of Munich) was the
  first person to really examine and discover the
  significance of the bee dance in communication

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Communication through Dance Language

• The Round Dance
• The Tail-Wagging Dance

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The Round Dance as Communication

• Method used by foraging bees to communicate to
  others about nearby food sources
• Von Frisch provides a description of how this
  communication takes place.

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Case 1 The objective is known to a group of bees

• A group of marked worker bees collecting from a
  source (a dish containing sugar water) stop
  making regular flights once the dish runs dry and
  simply return and sit around in the hive
• They still continue to scout the feeding place,
  often at first but with more spread out intervals
  later. All bees in the group are involved in the
  scouting but with differing levels of individual
  zeal
• The dish is refilled and a scouting bee returns
  with a stomach full of honey, makes a lively and
  excited run up the comb and feeds the others
  with the sugar solution

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Case 1 The objective is known to a group of bees

• The bee then goes through a series of movements
  describes as the round dance which arouses the
  interest of the bees around her.
• If group members were among those who were
  following her, they now fly out back to the
  feeding place. Once they return, they also
  perform the dance.
• This way, the entire group is notified and back
  in action.

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Case 1 The objective is known to a group of bees

• A returning food-distributing bee was also able
  to cause group members with whom she came in
  contact with to revisit the feeding place without
  dancing. This happened about 40 percent of the
  time whereas contact plus dancing had been
  effective about 90 percent of the time.
• If two different groups were collecting at
  different dishes and one of the dishes was
  refilled after an interruption in feeding, then
  the bees of the second group would also be
  induced into action by the dances of the
  successful group and would keep returning to
  examine their empty dish. This showed that the
  bees in a given group were not personally known
  to one another.

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Case 2 The objective is not known to the bees

• A bee discovers a source of food and through the
  round dance recruits helpers who are unfamiliar
  with the location of the food source.
• Similar situation occurs when members of a group
  who have found their food site to be replenished
  start performing the round dance and attract
  newcomers. Newcomers only join when there is
  dancing and the number that join depend on the
  number of dancers and the liveliness of the
  dancing.
• The liveliness and number of the dances depends
  upon the profitability of the food source. This
  is mainly determined by the quantity and
  sweetness of the sugar solution.
• Newcomers alerted by round dances search the
  vicinity in all directions
• Also may be influenced by olfactory cues of
  dancing bees search for flowers with the
  specific odor

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The Tail-Wagging Dance

• When food is more than 100 m from hive, round
  dance is replaced by tail-wagging.
• Tail-wagging also provides information as to the
  distance and direction of the goal.
• More complex than round dance.

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Factors Determining the Release and Liveliness of
the Dances

• Sweetness of Sugar Solution
• distension of the honey stomach shown to be
  unrelated to dancing level
• sorbitol experiment revealed dancing released
  solely or primarily through direct sense of taste
• change in sound production during waggling with
  higher sugar concentration though no evidence
  that higher sound was registered by nestmates as
  sign of better food
• Purity of Sweet Taste
• salt added
• hydrochloric acid, quinine

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Factors Determining the Release and Liveliness of
the Dances

• Ease of Obtaining the Solution
• quantity appears important
• unsure as to how this was measured. Von Frisch
  suggests time since longer times appeared to
  decrease dancing.
• Viscosity
• would mean more work and longer time.
• trisaccharide raffinose
• increases the liveliness of dances. Under natural
  circumstances, increased viscosity tends to
  correlate to richer sugar.

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Factors Determining the Release and Liveliness of
the Dances

• Load
• Added weight accompanied by somewhat increased
  flight time.
• Eagerness to dance not only undiminished but
  frequently clearly increased.
• Again, under natural circumstances, increased
  weight associated with higher sugar content of
  nectar
• Proximity
• Appears that bees dance for the same length of
  time
• Nearness allows closer bees to repeat dances more
  frequently

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Factors Determining the Release and Liveliness of
the Dances

• Floral Fragrance Form of Container
• floral scents increased liveliness of dances
• narrow tubes and clefts also resulted in
  increased dancing
• Uniform Flow
• food source must be continuous, bees do not dance
  after first flight
• exceptions great need, moderate shortage,
  unusual good find
• Status of Nourishment in Colony
• food supply (seasonal storage)
• famine, immediate dancing
• Relativity
• percentage of dancing foragers greater when 0.5M
  sucrose given after 0.25M solution then 0.5M
  solution given after 1M solution

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Factors Determining the Release and Liveliness of
the Dances

• Time of Day
• Flight intensity drops temporarily around noon
• Attributes this to diurnal periodicity in
  activity widely known among insects and other
  animals
• Weather
• take into account weather conditions in foraging
• several hours prior to storm, bees foraging from
  nearby sources continued to dance and forage
  while dancing for bees which were travelling to a
  source 6 km away declined rapidly and eventually
  stopped
• bees to nearby source kept foraging until storm
  actually broke

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Regulation of Supply and Demand on the Flower
Market

• Dance releases factors combined together result
  in a regulated exploitation of the sources of
  food in accordance with their profitability
• Scouts only signal nestmates for worthwhile
  sources of food
• Each individual bee concentrates on a relatively
  small area which it visits again and again.
  Economy of labor and limits unnecessary
  searching.
• Different species of plant are very distinct in
  their supply of nectar and its sugar content.
  Good sources of food are exploited more
  intensively. Likewise, when food supply runs out,
  bees may stay until situation improves or may
  stay home to avoid unnecessary risk in flight.
• Bees are able to adapt to diurnal variations

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Orientation and Other Topics

• Half the book is devoted to the dance language
  and how it relates to foraging. The other half
  deals with orientation and how bees are able to
  navigate from the hive to a foraging spot and
  back to the hive. Also mentions danceless
  communication in a couple pages in the middle of
  the book.
• Kirchner and Towne demonstrate that sound is an
  important part of the dance language by using a
  robotic bee to simulate dancing which a foraging
  bee would have produced.

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References

• Books
• Lindauer, Martin. (1971). Communication Among
  Social Bees. Cambridge, Massachusetts Harvard
  University Press.
• Seeley, Thomas D. (1995). The Wisdom of the
  Hive The Social Physiology of Honey Bee
  Colonies. Cambridge, Massachusetts Harvard
  University Press.
• Von Frisch, Karl. (1967). The Dance Language and
  Orientation of Bees. Cambridge, Massachusetts
  Harvard University Press.
• Links
• http//www.sciam.com/0694issue/0694kirchner.html
• http//www.cyberbee.net