Animal Behavior/Honeybee Foraging Behavioral Analysis

Honeybee Foraging Behavioral Analysis
The common honeybee (Apis mellifera) forages around the hive in search of resources. Usually this resource constitutes food in the form of pollinating flowers. Several landmark studies were performed in the middle of the 20th century to analyze how these social organisms communicated exact distances and direction to one another in order to effectively locate these resources. Karl von Frisch determined that honeybees perform two distinct dance routines that coincide with two different distance approximations made by the foraging bee. These two dances, the Round dance and the Waggle dance, communicate to the other the approximate distance from the hive to the new resource. Only the Waggle dance communicates direction (von Frisch 1967).

The Round dance is performed by the returning bee usually in complete darkness, vertically on a honeycomb. The circuitous motion attracts other foragers, which then learn that the resource is within approximately 50 meters of the hive. No direction is given by this routine (von Frisch). As a result, the newest foragers leave to search in all directions surrounding the hive. Behaviorally, this dance is energetically favorable due to the short distances travelled. In contrast, the Waggle dance is energetically unfavorable to the individual, but beneficial to the hive.

The Waggle dance is performed primarily when the resource is further than 50 meters. The returning forager either performs the dance on a vertical surface or a horizontal one. To determine distance and direction, the bee orientates itself relative to the sun. Any deviation from this point gives the angle the new foragers should pursue. If vertical, the bee orientates itself to gravity. Perpendicular to the ground becomes the reference point (i.e. the sun). Deviations from such relay direction accordingly. Distance is communicated by the length of the abdomen shake that forms the middle of a figure eight dance (von Frisch).

Kirchner et al. determined that the Round dance does not convey direction. By tipping several hives onto their horizontal axis and placed a resource 10 meters away, the reference heading was experimentally altered. Regardless of the hive orientation, the number of successful returning foragers was constant (1998). Once the distance crossed 50 meters, the success rate decreased for hives orientated horizontally, indicating direction is dependent on hive orientation for the waggle dance to be effective.

Honeybees foraging behavior can be interpreted from a historical or adaptationist view. Lindauer performed historical analysis that reveals that distantly related bees might have evolved through 3 stages of development: First stage analysis reveals that the genus Trigona conveyed direction by buzzing to gain their hivemates attention. The odors trapped on the bee trigger others to forage in search of the odor. The secondary stage involves marking the path from the resource to the hive with mandibular pheromones. She then buzzes, and the bees follow the scent markers. The third stage involves an in-flight "waggle dance" in the direction of the resource (Lindauer 1961).

Seely et al. provides an adaptationist theory on bee dance evolution. The foragers seek new resources to provide increased hive fitness. By dancing, the cost/benfit ratio is reduced to the individual level more so than a group of foragers expending energy searching in all directions all the time (Seely et al. 1998). Their study demonstrates that dancing has become an evolutionarily desirable trait because less time foraging allows for more time collecting the resource. Honeybee dancing provides an evolutionarily advantageous behavior which optimizes the hive's fitness.