Honeybee dance language: is it overrated?

In a recent article inTREE, Grüter and Farina [1] point out that in honeybee dance language the communication of spatial (navigational) information is embedded in several additional informational components. As a consequence, followers of dances do not need to perceive or use the spatial information encoded in the dances to show adaptive foraging behavior. However, whether this is sufficient to argue that the spatial information is of inferior functional significance is questionable. The authors try to show that the dance language is an inefficient communication system but fail to justify their metric of efficiency. To the best of our knowledge, there has not been a rigorous analysis to date of how to assess correctly the efficiency of the dance language or any other symbolic system that communicates spatial information. Citing Seeley [2], the authors calculate the total number of waggle runs danced by all dancers and compare this with the number of recruits that arrived at a feeder. However, a single waggle run is not a recruitment event because the potential followers need to be first alerted and guided to the dance. In addition, as the authors themselves later cite from another study [3], bees need to follow at least five–ten waggle runs to find the indicated food source successfully. Thus, calculation of dance language efficiency needs to take into account not only the number of successful recruits, but also the number of recruitment events and potential followers. The concept of social and private information introduced by the authors [1] stresses the significance of behavioral plasticity in the responses of dance followers but errs in the assumption that public information is more reliable than is social information. This is not true for honeybees because of the unique character of social communication in their colonies and in eusocial insect societies in general. Foragers do not search for food for their personal needs but for those of the colony [4]. In eusocial systems, social signals and cues, such as dance signals, need to be reliable. There is ample evidence that dance information is continuously updated and reliable under natural conditions and tuned to the availability of floral resources and the needs of the colony [2,3,5,6]. The dancers provide all the information they have to address all possible followers, experienced or inexperienced. Dance information is better understood as a social reference system to which foragers adjust their behavior, rather than as a back-up system for private information. The fact that followers can be selective about receiving specific signals does not negate the importance of any of the dance signals, which engage different sensory modalities. The relative importance of the different signals depends on