E104 - L12

Waggle dance

honey bee communication

waggle dance

cues

• info passively left in environment by an animal

• used by anyone

• tracks, odors, sounds, etc

signals

• info intentionally sent by one animal to another

• usually within species

  • eavesdropping exits

threat signals evolve from…

the movement preceding an attack

bumble bee dances…

1. hypothetical ancestor: inactive workers can use activity in nest (a cue) to tell how much foraging is occurring

2. if worker exaggerates wildly their activity in nest after finding food for first time, this is now a signal that has evolved from a cue

selection works to…

increas

• production of cue (now a signal)

• sensitivity of receiver

what context does message produce?

predator present

who is the receiver & what is their response?

prey of that predator respond to the call by running

same signal can have…

mamy meanings

bird mating signals (visual & vocal) can…

be received & used by both males & females

• territorial call can also be a mating call

multiple meaning is…

very common in social insects

• castes

Honey bee chemical communication signals

(pheromones)

• fertility

• alarm

• flower membership

• mate attraction

Honey bee mechanical/acoustical communication signals

• dances

• other shaking

• buzzing

• vibrating type signals

foragers produce…

two kinds of signals

• signals with info about food resources

• signals to coordinate activities

History of waggle dance

dance of joy

• bees find food then dance to celebrate

• communicate food resources

• founded by Karl von Frisch

Karl von Frisch

• color vision in bees

• polarized light vision in bees

• 1930s: started working on waggle dance

• 1940s: published major work on waggle dance

bees can be…

trained to feeders over great distances

bees can be individually…

marked at the feeder

• can check if bees dance after they find a rich food source by watching inside hive for marked bees

color vision

• train bees to a food reward placed over a color

• see if bee goes to proper color when it returns

  • can move color around

  • can train to odors

• bees can see & remember many patterns

bees don’t see…

red, but do see UV which we do not

flowers looks very diff to bees

nectar guides

finding meaning of waggle dance

suspected it could be a recruitment signal b/c bees seemed to be able to talk to each other

• saw bees did the dance after finding food

bee would have to communicate distance & direction for it to work

• something must changes as distance grows & direction changes

waggle dance angle is…

vertical

• direction outside has to have a reference point

• Von Frisch suspected sun is the reference point

• watched bees dancing for the same sight all day

  • if sun is reference point then angle of dance should change continuously throughout the day

• Von Frisch also found found points by reading dances

bees can tell…

each other where food is

bees perform a number of…

dances that correlates with how good site is

• an individual dance is same for a good or great site

a good site for bees will…

attract maybe a hundred foragers while a poor one only a few

bee flight is…

costly

• can fly up to 12 km from nest

bees trained to…

three feeders that differ in nectar concentration or distance

bees do not…

use nectar concentration as the only measure of quality

• rate of energy transfer back to colony that matters

waggle dance is sent via…

sound, motion, smell, & substrate vibration

waggle dance pheromone is a…

blend of several hydrocarbons

• only recently identified & poorly understood

waggle dance is just…

one dance

there are many dances & other signals that…

together make up a dance language used to control foraging

bee foragers collect…

nectar but the other bees processes it

• requires much coordination & signaling

optic flow

refers to rate of image flow across retina

• ex) sitting on a train & looking out the window in fixed position = some sense of how fast you are going

optic flow experiment

make bee foragers fly down a narrow tube to a feeder

• narrow tube = increase optic flow but not time or energy used

results:

bees flew down a 6m tunnel to a feeder with sugar water

• they went back in hive & danced

recruits flew to a feeder 70m away

• flew over closer feeder

bees use optic flow to measure distance traveled