For humans, dancing can be a form of communication that conveys a lot of nonverbal information. Although we mainly partake in dancing for entertainment reasons, we must not forget that it is guided by social conventions and conceived guidelines. Therefore, our bodies can say a lot more than we think based on how we move. Honeybees, too, use dancing as a means to communicate with one another. Although it is less for entertainment as it is for survival, they follow certain social patterns and expectancies just as humans do. Jacobus Biesmeijer and Thomas Seeley’s research on the waggle dance of honeybees illustrates that honeybees use a form of dance in three situations when foraging for food. The followers of the waggle dance “can use location information acquired from the dance to find the indicated food source” which in turn “contributes to the foraging success of a honey bee colony” (Biesmeijer & Seeley, 133). Information on the type of food (pollen vs. nectar), the direction, and the distance of the food source can be conveyed through this dance. They studied the following three contexts:
1) The novice forager finding its first food source
2) The experienced forager whose foraging expedition has been interrupted
3) The experienced forager that is engaged in foraging
In all three contexts, the honeybee can either use the waggle dance information to guide its search or search independently for a food source without following any dance.
Biesmeijer and Seeley set up an observational hive in which the bees were forced to enter and leave the hive from one side of the cove. Consequently, all of the nectar unloading and all of the dancing could be recorded methodically. They performed three trials of observation: during the spring, summer, and fall. Depending on the trial, thirty or sixty bees were labeled for individual identification. The observer noted the following of a waggle dance if a bee was within one bee length of the dancer, faced the dancer, and moved so that its head always faced the performing dancer. Honeybees that had early excursions shorter than ten minutes and did not unload nectar or pollen upon return (thus performing an orientation flight) were considered novice foragers. The 48 novice foragers were observed from when their attempts of foraging began until when they engaged in successful food collection. Nineteen of those honeybees, or 40%, attempted to forage without the aid of information from any type of waggle dance. Eighteen honeybees, or 37%, relied on the waggle dance of other bees. The remaining 11 honeybees, or 23%, relied evenly on both. It is interesting to note that although there were differences in how the honeybees foraged for food, they did not differ statistically in the number of search trips, around 4.3 trips, required to find their first food source (Biesmeijer & Seeley, 136).
Sixty-three experienced foragers were observed on the 512 days determined as interrupted forager days. The behavior of interest was how the honeybees went back to foraging, if they followed a waggle dance to resume or if they went independently to find the same source. 63% of the time, the bees made trips that were not preceded by the following of a waggle dance, while 37% of the time, the bees made trips preceded by the following of waggle dance (termed reactivation). They found through statistical analysis that success was only slightly (but not significantly) higher for reactivation trips (preceded by the following of a waggle dance) than for trips that were not preceded by the following of a waggle dance (Biesmeijer & Seeley, 137). Looking at the trends over the whole day, experienced foragers followed the waggle dance for 16.6% of their daily trips when there were no interruptions.
When looking at the overall foraging activity for each experienced forager over their lifetime, Biesmeijer and Seeley found that “the percentage of first trips [of the day] by reactivation decreased over days of foraging” for most of the trials (trials 1 and 3)(Biesmeijer & Seeley, 137). In other words, experienced honeybees that lived longer tended to decrease their following of the waggle dance before going out on their first foraging trip of the day.
It is also interesting that Biesmeijer and Seeley found “dance following much more common after a failed trip [. . .] than after a successful one” (Biesmeijer & Seeley, 137). Honeybees that did not follow a waggle dance and failed to find food were 22-33% likely to follow a dance before their next trip. If the honeybees were successful however, that probability of following a waggle dance before their next trip dropped to 6-8%. The same trends were found even for honeybees that did follow a waggle dance initially. Honeybees that followed a waggle dance and failed to find food were 60-80% likely to follow a dance for their next trip. However, if the honeybees were successful in finding food, that probability dropped to 22-44% of following a waggle dance for their next trip (Biesmeijer & Seeley, 138).
After reading the results, let’s revisit the purpose of the study: to examine the extent to which worker honeybees acquire information from waggle dances throughout their careers as foragers (Biesmeijer & Seeley, 139). As a recap, we found that 37% of the novice foragers followed a waggle dance to find their first food source, experienced honeybees followed waggle dances 37% of the time after their foraging was interrupted, and experienced foragers followed dances before 17-20% of their trips, especially if their previous trips resulted in no food.
Biesmeijer and Seeley’s results provide some interesting discussion topics. First of all, although only 37% of novice bees relied on the waggle dance to find their first food source, if no food source were found, they were more likely to follow a waggle dance for their next trip. On average, it took novice honeybees 4.3 trips to find their first food source. Therefore, I hypothesize that if we were to graph the behavior of bees over trips, we would see a slight increase in the following of waggle dances until that 4.3 marker and then a decrease (since the results showed that if successful in finding food, honeybees were less like to follow a dance after). This decrease would continue since the results also showed that experience honeybees who lived longer and gained more experience were less likely to follow waggle dances.
Another topic I would like to discuss is the availability of waggle dances, in other words, how many of the honeybees that knew the location of food sources actually produced a waggle dance. This number would alter how many honeybees followed the dance such that if there was a high availability of dancing bees, the amount of honeybees following the dance would be higher than if there were not that many honeybees producing the waggle dance. In addition, that could say something about the evolutionary history of the waggle dance. The balance between the amount of waggle dance produced and the amount of following would, I assume, be tweaked through evolutionary forces. With too much dancing available, this would take up unnecessary time and energy of the dancing bees which they could be devoting to other tasks. However with too little dancing available, the following of the dance would be inefficient if there were not enough dances to learn from.
I also wonder why such a phenomena occurs if the success of finding food does not differ that greatly between the followers of the dance and those that did not follow the waggle dance. Does this communication system benefit the bees in a different way? Even if both the follower and the non-follower brings back food with the same probability, does following the dance allow the bees to find the food faster? Biesmeijer and Seeley offer the following explanation: recruitment (following the waggle dance) “guides a bee to a much richer food source [. . .] and lets a bee avoid the cost of inspection flights” (Biesmeijer & Seeley, 141). However, they do admit that only through further study will they be able to make a stronger hypothesis regarding the relative benefits of the waggle dance and how it improves the economy of the colony.
Biesmeijer, J. C. & Seeley, T. D. (2005) The use of waggle dance information by honeybees throughout their foraging careers. Behavioral Ecology and Sociobiology, 59(1), 133-142.