dancing bees heather mahaney september 26 th, 2002

Dancing Bees

Heather Mahaney

September 26th, 2002

Discovery

• Karl von Frisch• Vienna• Nobel Prize 1973• The Dance Language

and Orientation of Bees

• Experiments began 1923

Methods

• Observation Hives– Large – 6 combs

– Small – 2 combs

– Shape – Flat

– Combs visible

– Temperature Regulation

– Wedges

Labeling

• Color Lacquer Dissolved in Alcohol

• 5 different colors

• 2 different spots on the thorax

• Duration – several weeks

• Method – mark bees while they are getting sugar water

Labeling

Artificial Feeding

• Watch glass filled with sugar water

• Colored paper under dish to resemble flower

• Attract by putting drops of sugar water in the hive entrance.

• Trail to artificial flower

• Only want bees from one hive

Challenges

• Spring Time– Natural food sources are good.– Hard to attract to artificial sources.

• Late Summer– Natural food sources are scarce.– Hard to keep other bees away.

Nutrition

• The hive needs both nectar and pollen to survive– Nectar – 120 kg– Pollen – 20 kg

• Must have correct balance

• Consume and Store

Food Sources

• Foragers monitor food sources within a 62 sq mile radius of the hive

• Choose the best food sources

• Constantly changing needs and resources

Foragers

• Each hive sends several thousand bees to collect food daily.– ¼ of total population

• No Scouts

• When a good source is found, other bees are recruited there to gather food.

Foraging

• Each bee can find flowers over 3.7 miles away.

• Travel at 5.5 mph

• 400,000 body lengths = 372 human miles

Foraging

• Covers a 62 sq mile distance around hive.

• Most foraging within ½ mile

• Large area = large variety of food sources

• Best shortly after blooming

Feeding

• Bee finds good food source

• Fills honey stomach

• Flies home

• Finds recipients

• Drops of honey water in mouth

• Bees drink through probiscus

• Dance

Dance - Measuring

• von Frisch used a protractor and drew lines with on the glass to measure angles

• Also used a rotating disk with gridlines 2cm apart placed parallel to the direction of the dance

• Measured length of circuits with a stop watch

• Motion picture

Dance – Process

• Bee distributes food

• Dances

• Distrubutes more food

• Dances again …

• Done in highly populated area

• Others follow with their antenna against her abdomen.

Dance - Types

• Tail-Waggle – greater than 100 m

• Transition: Round -Waggle – 25m to 100m

• Round – Food source within 10m

Round Dance

• Bee runs in a small circle

• Runs over 6 adjacent cells

• Reverses and returns

Tail - Waggle

• Run in a straight line

• Return in a semicircle

• Run again

• Return on the other side

Tail - Waggle

• Direction indicates direction of source

• Distance proportional to distance of source

• Buzzing

• Low sugar – little wagging, no buzzing

Surveillance

• Colonies effectively survey their foraging range for new patches of flowers.

• When sites are found, bees return to the hive and dance to recruit others.

• Upon discovery, bees dispatch quickly to the new site before competitors can find it.

Food Sources

• Colonies concentrate their resources on the riches food sources.

• When food is scare, bees are less selective.

• When food is plentiful, bees feed on only the best food sources.

Beeswax Combs

• Used for rearing and food storage.

• Initially build 20,000 cells

• Up to 100,000 cells by the end of the summer

• Create new combs when current combs are full and nectar is prolific

Pollen

• Colonies only store small amounts of pollen.

• 50kg of honey but only 1kg of pollen

• Pollen contains protein, constantly consumed over the summer when plentiful.

Water

• Colonies adjust their water intake due to environmental situations

• Colony needs water to regulate hive temperature on hot days

• Nurse bees need water to produce liquid food for larvae on cool days