When do honey bees use When do honey bees use snapshots during navigation?snapshots during navigation?

By Frank BartlettBy Frank Bartlett

Bees and wasps learn Bees and wasps learn information about visual information about visual landmarks near the goallandmarks near the goal

Edge orientation (Srinivasan et al., Edge orientation (Srinivasan et al., 1994)1994)Color (von Frisch, 1967; Cheng et Color (von Frisch, 1967; Cheng et al., 1986)al., 1986)Size (Cartwright & Collett, 1979; Size (Cartwright & Collett, 1979; Ronacher, 1998)Ronacher, 1998)Spatial relationships among multiple Spatial relationships among multiple landmarks (Cartwright & Collett, landmarks (Cartwright & Collett, 1983)1983)

How is this information How is this information subsequently used over subsequently used over successive visits?successive visits?

Snapshot template matching Snapshot template matching (Cartwright & Collett, 1983) (Cartwright & Collett, 1983)

Niko Tinbergen (1938)

Departing Wasp

Returning Wasp

What is snapshot navigation?What is snapshot navigation?

View of landmarks is memorized from the

goal

After Cartwright & Collett, 1983 Upon return the

bee steers flight by sequentially matching her

memory to the environment

Experiments revealing the Experiments revealing the contents of snapshot memoriescontents 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)

Single Landmark

From Cartwright & Collett, 1983

Training

Distance from landmark

Landmark

Goal

3 equidistant Landmarks

Training

Landmarks

Goal

Testing the snapshot hypothesis Testing the snapshot hypothesis in a small scale arena in a small scale arena

environmentenvironment► The snapshot hypothesis makes The snapshot hypothesis makes

accurate predictions about accurate predictions about where insects should spend their where insects should spend their time searching for the goal. time searching for the goal.

Can we replicate these findings?Can we replicate these findings?

► The hypothesis also generates The hypothesis also generates predictions of flight paths to the predictions of flight paths to the goal from more distant locations.goal from more distant locations.

Do steering commands Do steering commands generated by snapshot matching generated by snapshot matching predict honey bee flight behavior predict honey bee flight behavior while en-route to a familiar goal?while en-route to a familiar goal?

This has not been tested This has not been tested explicitly.explicitly.

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.

MethodsMethods

Search distributionsSearch distributions

Replication of Cartwright & Collett (1983)

Training

2 x

-- 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

Model

The model predictions were generated in Matlab based on the algorithm provided by Cartwright & Collett (1983)

Flight paths to the goal Flight paths to the goal locationlocation

Bee Flights

E

F

Bees appear to be attracted to the nearest landmark and use it as a beacon even over very short distances

ConclusionsConclusions►Search at the goalSearch at the goal

Consistent with previous findingsConsistent with previous findings►Steering from more remote Steering from more remote

locations using template matchinglocations using template matching Bee flights not consistent with model Bee flights not consistent with model

predictionspredictions Strong role of beaconsStrong role of beacons

►Consistent with other results (Fry & Consistent with other results (Fry & Wehner, 2005; Collett & Baron, 1994) but Wehner, 2005; Collett & Baron, 1994) but extended to shorter distances and more extended to shorter distances and more complex arrayscomplex arrays

►Beacon selection probably driven by visual Beacon selection probably driven by visual saliencesalience

AcknowledgmentsAcknowledgments

NSF IGERTNSF IGERT

Fred DyerFred Dyer

Steven FrySteven Fry

Mike MackMike Mack

Chris SpeilburgChris Speilburg

Yoav LittmanYoav Littman

Jenny JonesJenny Jones

Lora BramlettLora Bramlett

Kourtney TrudgenKourtney Trudgen

Lauren DavenportLauren Davenport

Short range visual navigation Short range visual navigation in flying hymenopterans in flying hymenopterans

► Bees and wasp learn Bees and wasp learn information about visual information about visual landmarks near the goallandmarks near the goal Edge orientation (Srinivasan et Edge orientation (Srinivasan et

al.; 1994)al.; 1994) Color (von Frisch, 1967; Cheng Color (von Frisch, 1967; Cheng

et al., 1986)et al., 1986) Size (Cartwright & Collett, Size (Cartwright & Collett,

1979; Ronacher, 1998)1979; Ronacher, 1998) Spatial relationships among Spatial relationships among

multiple landmarks multiple landmarks (Cartwright & Collett; 1983)(Cartwright & Collett; 1983)

► How is this information How is this information represented and represented and subsequently used over subsequently used over successive visits?successive visits? Snapshot template matching Snapshot template matching

(Cartrwright & Collett; 1983) (Cartrwright & Collett; 1983)

Niko Tinbergen (1938)

How is this information learned?How is this information learned?The turn-back-and-lookThe turn-back-and-look

Tenth VisitFirst Visit

From Lehrer, 1993

--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

What is snapshot navigation?What is snapshot navigation?

View of landmarks is memorized from the

goal

After Cartwright & Collett, 1983

-- 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.

Bee sequentially matches her

memory to the environment upon

return

Model predictions vs. Flight Model predictions vs. Flight Behavior:Behavior:

pushed off coursepushed off course

E

F

After their course is diverted by the novel landmark, bees again use the next nearest landmark as a beacon to guide flight.

Finding the matchFinding the match► Near the goal bees prefer to Near the goal bees prefer to

maintain a southern facing body maintain a southern facing body axisaxis Snapshot is probably anchored Snapshot is probably anchored

to the retina (Collett & Baron, to the retina (Collett & Baron, 1994)1994)

► Bees perform bouts of lateral flight Bees perform bouts of lateral flight during their return to the goalduring their return to the goal Probably to help bring their Probably to help bring their

memory into register with their memory into register with their current view (Collett & Reese, current view (Collett & Reese, 1997)1997)

E

F

Model predictions vs. flight Model predictions vs. flight Behavior:Behavior:

middle landmark removedmiddle landmark removed

Model predictions vs. Flight Model predictions vs. Flight Behavior:Behavior:

farthest landmark removedfarthest landmark removed

E

F

Model predictions vs. Flight Model predictions vs. Flight Behavior: Behavior: removed nearest removed nearest

landmarklandmark

E

F

Fixed body axis and scanning Fixed body axis and scanning flightsflights

2060 * 1830 * 1550

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.

Snapshot overviewSnapshot overview

► Insects memorize a visual template or “snapshot” of Insects memorize a visual template or “snapshot” of landmarks they experience at important locations of landmarks they experience at important locations of their environmenttheir environment

► The memory encodes the sizes and retinal locations The memory encodes the sizes and retinal locations of landmarksof landmarks

► Insects sequentially match this template to the Insects sequentially match this template to the environment upon return while maintaining environment upon return while maintaining consistent body alignmentconsistent body alignment

► Lateral scanning movement may aid the matching Lateral scanning movement may aid the matching process process

Snapshot overviewSnapshot overview

► Insects memorize a visual template or “snapshot” of Insects memorize a visual template or “snapshot” of landmarks they experience at important locations of landmarks they experience at important locations of their environmenttheir environment

► The memory encodes the sizes and retinal locations The memory encodes the sizes and retinal locations of landmarksof landmarks

► Insects sequentially match this template to the Insects sequentially match this template to the environment upon return while maintaining environment upon return while maintaining consistent body alignmentconsistent body alignment

► Lateral scanning movement may aid the matching Lateral scanning movement may aid the matching process process

Testing the snapshot hypothesis Testing the snapshot hypothesis in a small scale arena in a small scale arena

environmentenvironment► Honey bee flight behavior during other visual Honey bee flight behavior during other visual

navigation experiments in our apparatus appeared navigation experiments in our apparatus appeared inconsistent with snapshot guidance.inconsistent with snapshot guidance.

► Investigated elements of snapshot navigation in a Investigated elements of snapshot navigation in a carefully controlled arena environmentcarefully controlled arena environment

Snapshot predictions of search behavior near the goal Snapshot predictions of search behavior near the goal location (tested by Cartwright & Collett, 1979, 1982; Cheng, location (tested by Cartwright & Collett, 1979, 1982; Cheng, 1999)1999)

Predictions of flights paths to the goal from distances of up to Predictions of flights paths to the goal from distances of up to two meters (largely untested)two meters (largely untested)

Consistent body axis orientation near the goal (Collett & Consistent body axis orientation near the goal (Collett & Baron, 1994)Baron, 1994)

Lateral scanning flights near the goal (Collett & Rees, 1997)Lateral scanning flights near the goal (Collett & Rees, 1997)