Waggle Dance Essay Research Paper Communication Among — страница 2

  • Просмотров 286
  • Скачиваний 5
  • Размер файла 17

opposite direction. After repeating the dance numerous times, the scout then stops and gives some of the other workers a taste of the food it has found. The worker honeybees that have just witnessed the dance are then able to go collect the specified food. The different aspects of the waggle dance also convey different information. The direction of the straight part of the dance conveys the direction in which the food is located. The speed at which the dance is repeated conveys the distance to the food source. Frisch noticed that when the hive was horizontal, the straight part of the dance was pointed in almost the exact direction of the food source. However, it took many years of research to come up with an explanation as to how the honeybees are able to convert the direction of

the straight run danced in a vertical hive, to the horizontal ground outside. Frisch noticed that if he kept the food source in the same location, the bees in the vertical hive would change the direction of the straight run proportionally as the day progressed. He was therefore able to show that the scout honeybee based the direction of the straight portion of the dance relative to the position of the sun in the sky. If the food was located in the direction of the sun, then the scout would dance the straight part straight up. If the food was at another angle in relation to the sun, then the scout would dance the straight part at the same angle to the vertical . The other worker bees will translate this angle when they leave the hive in relation to the angle between the sun and

the food source by means of heat sensing as well as an internal clock that allows them to know where the sun is in the sky. The internal clock within the honeybees appears to be related to the honeybees metabolic rate. The speed at which the scout honeybee performs both parts of the waggle dance is also very important. Frisch noticed, that the speed in which the waggle dance was performed indicated the approximate distance to the food source; the faster the dance, the closer the food. It was relatively easy for Frisch to understand the importance of the speed of the dance, as there is a lot of variation between the speeds of the straight part of the dance when using two different distances to the food source. Also, the faster the scout honeybee actually vibrates its body,

indicates the quality of the food source. If the food source is extremely concentrated, then the scout will waggle with a lot of vigor. Karl von Frisch s theory of honeybee communication went unchallenged and unchanged until 1960, when Adrian M. Wenner and Harald E. Esch began to question Frisch s hypothesis. Although they were both working in two separate places, Wenner at the University of California and Esch at the University of Notre Dame, they both questioned how, according to Frisch s theory, the honeybees were able to see the dance inside of the darkened hive. Wenner suggested that the other worker bees were able to recognize the specific dance of the scout bee, not by seeing the dance, but by hearing and sensing the dance. He said, that when the scout performed the dance

it caused vibrations through the hive which conveyed the dance s information to the surrounding worker bees. As well, Wenner observed that the bees also emitted very low frequency buzzing. He theorized that although the waggle dance is used to convey information regarding food between honeybees, it is only understood and communicated through vibrations. Another problem that bothered Esch, was how the bees were able to judge distances between the hive and the food source. Esch realized that bees have compound eyes, and that they were able to judge distances by the flickering motions reflected into their eyes as they flew. This concept is know as the flicker effect . He proved this theory by doing numerous experiments, which involved setting up a food source in the middle of a

tunnel, and then switching the tunnel when the other worker bees came to collect the food. When he did not change the tunnel, then the other workers were able to locate the food source immediately. When he replaced the original tunnel with a narrower tunnel with vertical stripes, which would cause more flickering, he found that the other workers would search for the food well short of were it actually was. Consequently, when the tunnel was replaced by a wider tunnel with stripes, which would appear to cause less flickering motion, he found that the bees started searching for the food farther past were the food actually was located. Esch, along with another scientist named Burns also discovered from the tunnel experiments, that the flicker motion in judging distances also effects