When do honey bees use snapshots during navigation?

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When do honey bees use snapshots during
navigation?

• By Frank Bartlett

Bees and wasps learn information about visual
landmarks near the goal Edge orientation
(Srinivasan et al., 1994) Color (von Frisch,
1967 Cheng et al., 1986) Size (Cartwright
Collett, 1979 Ronacher, 1998) Spatial
relationships among multiple landmarks
(Cartwright Collett, 1983) How is this
information subsequently used over successive
visits? Snapshot template matching (Cartwright
Collett, 1983)
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What is snapshot navigation?
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Experiments revealing the contents of snapshot
memories
-- When a single landmark is present bees rely
on retinal image size. -- When multiple
landmarks are available bees rely on the
inter-landmark angles (or the spaces between
landmarks)
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Testing the snapshot hypothesis in a small scale
arena environment

• The snapshot hypothesis makes accurate
  predictions about where insects should spend
  their time searching for the goal.
• Can we replicate these findings?
• The hypothesis also generates predictions of
  flight paths to the goal from more distant
  locations.
• Do steering commands generated by snapshot
  matching predict honey bee flight behavior while
  en-route to a familiar goal?
• This has not been tested explicitly.

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Methods
Training bees visit an initial landmark
configuration (60 visits) Testing track with
original configuration and other landmark
manipulations The camera records bee position
and body axis orientation at 60 Hz.
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Search distributions
-- When a single landmark is present bees rely
on retinal image size. -- When multiple
landmarks are available bees rely on the
inter-landmark angles -- These results are
consistent with previous studies
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Flight paths to the goal location
The model predictions were generated in Matlab
based on the algorithm provided by Cartwright
Collett (1983)
Bees appear to be attracted to the nearest
landmark and use it as a beacon even over very
short distances
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Conclusions

• Search at the goal
• Consistent with previous findings
• Steering from more remote locations using
  template matching
• Bee flights not consistent with model predictions
• Strong role of beacons
• Consistent with other results (Fry Wehner,
  2005 Collett Baron, 1994) but extended to
  shorter distances and more complex arrays
• Beacon selection probably driven by visual
  salience

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Acknowledgments

• Yoav Littman
• Jenny Jones
• Lora Bramlett
• Kourtney Trudgen
• Lauren Davenport

• NSF IGERT
• Fred Dyer
• Steven Fry
• Mike Mack
• Chris Speilburg

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Short range visual navigation in flying
hymenopterans

• Bees and wasp learn information about visual
  landmarks near the goal
• Edge orientation (Srinivasan et al. 1994)
• Color (von Frisch, 1967 Cheng et al., 1986)
• Size (Cartwright Collett, 1979 Ronacher, 1998)
• Spatial relationships among multiple landmarks
  (Cartwright Collett 1983)
• How is this information represented and
  subsequently used over successive visits?
• Snapshot template matching (Cartrwright
  Collett 1983)

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How is this information learned?The
turn-back-and-look
--Motion parallax cues allow bees to distinguish
nearby landmarks from distant landmarks (Lehrer,
1993)
--Believed to aid in the selection and learning
of the landmarks near a goal
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What is snapshot navigation?
-- Insect visual memory is thought to be
comprised of a two dimensional snapshot that
encodes the retinotopic sizes and positions of
landmarks and the gaps between them.
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Model predictions vs. Flight Behaviorpushed off
course
After their course is diverted by the novel
landmark, bees again use the next nearest
landmark as a beacon to guide flight.
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Finding the match

• Near the goal bees prefer to maintain a southern
  facing body axis
• Snapshot is probably anchored to the retina
  (Collett Baron, 1994)
• Bees perform bouts of lateral flight during their
  return to the goal
• Probably to help bring their memory into register
  with their current view (Collett Reese, 1997)

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Model predictions vs. flight Behaviormiddle
landmark removed
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Model predictions vs. Flight Behaviorfarthest
landmark removed
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Model predictions vs. Flight Behavior removed
nearest landmark
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Fixed body axis and scanning flights
Bees preferred a southern facing body axis
orientation during their first pass through the
goal region
Bees rarely performed lateral scanning flights
near the landmark. Circling flights were the
norm.
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Snapshot overview

• Insects memorize a visual template or snapshot
  of landmarks they experience at important
  locations of their environment
• The memory encodes the sizes and retinal
  locations of landmarks
• Insects sequentially match this template to the
  environment upon return while maintaining
  consistent body alignment
• Lateral scanning movement may aid the matching
  process

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Snapshot overview

• Insects memorize a visual template or snapshot
  of landmarks they experience at important
  locations of their environment
• The memory encodes the sizes and retinal
  locations of landmarks
• Insects sequentially match this template to the
  environment upon return while maintaining
  consistent body alignment
• Lateral scanning movement may aid the matching
  process

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Testing the snapshot hypothesis in a small scale
arena environment

• Honey bee flight behavior during other visual
  navigation experiments in our apparatus appeared
  inconsistent with snapshot guidance.
• Investigated elements of snapshot navigation in a
  carefully controlled arena environment
• Snapshot predictions of search behavior near the
  goal location (tested by Cartwright Collett,
  1979, 1982 Cheng, 1999)
• Predictions of flights paths to the goal from
  distances of up to two meters (largely untested)
• Consistent body axis orientation near the goal
  (Collett Baron, 1994)
• Lateral scanning flights near the goal (Collett
  Rees, 1997)