Honeybee Waggle Dance Research Articles

Automatic detection and decoding of honey bee waggle dances.

The waggle dance is one of the most popular examples of animal communication. Forager bees direct their nestmates to profitable resources via a complex motor display. Essentially, the dance encodes the polar coordinates to the resource in the field. Unemployed foragers follow the dancer’s movements and then search for the advertised spots in the field. Throughout the last decades, biologists have employed different techniques to measure key characteristics of the waggle dance and decode the information it conveys. Early techniques involved the use of protractors and stopwatches to measure the dance orientation and duration directly from the observation hive. Recent approaches employ digital video recordings and manual measurements on screen. However, manual approaches are very time-consuming. Most studies, therefore, regard only small numbers of animals in short periods of time. We have developed a system capable of automatically detecting, decoding and mapping communication dances in real-time. In this paper, we describe our recording setup, the image processing steps performed for dance detection and decoding and an algorithm to map dances to the field. The proposed system performs with a detection accuracy of 90.07%. The decoded waggle orientation has an average error of -2.92° (± 7.37°), well within the range of human error. To evaluate and exemplify the system’s performance, a group of bees was trained to an artificial feeder, and all dances in the colony were automatically detected, decoded and mapped. The system presented here is the first of this kind made publicly available, including source code and hardware specifications. We hope this will foster quantitative analyses of the honey bee waggle dance.

Importance of wing movements for information transfer during honey bee waggle dance

AbstractThere is growing evidence indicating that dancing honeybees can transfer some information about the found food source by means of wing movements. However, the available data are limited and inconclusive in the case of the frequency of wing beats. Therefore, in this study, the hypothesis that the wing beats convey information about the foraging distance was re‐examined. Honeybee dances were recorded using a high‐speed camera, and foraging distances were decoded from the duration of waggle phases. Dancing honeybees moved their wings for almost half (47%) of the duration of waggle phases. The number of wing‐beating pulses and the combined duration of wing beating were strongly positively correlated with the duration of waggle phases (p < .0014), whereas the mean frequency of wing beats, the mean duration of wing‐beating pulses and the mean number of wing beats in one wing‐beating pulse were not correlated with the duration of waggle phases (p > .05). Nevertheless, both the mean frequency of wing beats and the mean number of wing beats in one wing‐beating pulse were positively correlated with the mean frequency of abdomen waggles (p < .0014). They were also positively correlated with the mean frequency of wing‐beating pulses (p < .0014). The correlation matrix revealed that there were two groups of dance components that were positively correlated within groups, but negatively correlated between groups. One of the groups provided information about distance to the food source. We hypothesise that the other group, including the number of wing beats in one pulse, the frequency of wing beats, the frequency of wing‐beating pulses and the frequency of abdomen waggles, may provide information about the motivational state of foragers.

Direct Visual Observation of Wing Movements during the Honey Bee Waggle Dance

Recruitment-related behaviours such as waggle dances enable honey bee foragers to inform their nestmates about the location of important resources. However, it is still not known how the information contained in a dance performed in the darkness of the nest is transferred to followers. Although, there are findings indicating that dancing honey bees produce airborne sounds which may convey the information, there has only been indirect evidence that moving wings are the source of these airborne sounds. In this study, honey bee dances were recorded using a high-speed camera in order to directly observe and precisely measure the frequency of wing beats and abdomen wags of dancers. Dancing bees moved their wings for 40.4% of the duration of a waggle run and for only 8.1% of the duration of a circle run. The episodes of wing movements consisted of one to five wing beats and were separated by intervals of motionless wings. The mean frequency of wing beats was 167.0 Hz and significantly differed depending on the number of wing beats in one episode (p < 0.001) and the position of the wings (p = 0.007). The mean frequency of abdomen wags was 14.6 Hz. The mean number of followers was 7.9 and significantly more of them gathered around the abdomens of dancers than around their heads and thoraxes (p = 0.001). The results of this study support the assumption that moving wings are the source of airborne sounds emitted during honey bee dances.

MRoCS: A new multi-robot communication system based on passive action recognition

Multi-robot search-and-rescue missions often face major challenges in adverse environments due to the limitations of traditional implicit and explicit communication. This paper proposes a novel multi-robot communication system (MRoCS), which uses a passive action recognition technique that overcomes the shortcomings of traditional models. The proposed MRoCS relies on individual motion, by mimicking the waggle dance of honey bees and thus forming and recognising different patterns accordingly. The system was successfully designed and implemented in simulation and with real robots. Experimental results show that, the pattern recognition process successfully reported high sensitivity with good precision in all cases for three different patterns thus corroborating our hypothesis.

Dancing to her own beat: honey bee foragers communicate via individually calibrated waggle dances.

Communication signals often vary between individuals, even when one expects selection to favour accuracy and precision, such as the honey bee waggle dance, where foragers communicate to nestmates the direction and distance to a resource. Although many studies have examined intra-dance variation, or the variation within a dance, less is known about inter-dance variation, or the variation between dances. This is particularly true for distance communication. Here, we trained individually marked bees from three colonies to forage at feeders of known distances and monitored their dances to determine individual communication variation. We found that each honey bee possesses her own calibration: individual duration-distance calibrations varied significantly in both slopes and intercepts. The variation may incur a cost for communication, such that a dancer and recruit may misunderstand the communicated distance by as much as 50%. Future work is needed to understand better the mechanisms and consequences of individual variation in communication.

Following the dance: Ground survey of flowers and flower-visiting insects in a summer foraging hotspot identified via honey bee waggle dance decoding

Decoding of honey bee waggle dances has previously shown that average foraging distances are longest during July and August in Sussex, United Kingdom, indicating a scarcity of summer floral resources. However, it also identified a summer foraging ‘hotspot’ in agricultural land at 2–3km distance. Unfortunately, dance decoding does not yield precise foraging locations or information on the flower species visited. Therefore, we surveyed this hotspot during July and August 2012 and 2013 in order to identify the habitats and flower species used by honey bees and other flower-visiting insects (FVI).The hotspot area consisted predominantly of four habitat types potentially attractive to FVI: pasture fields, field margins/hedgerows of arable fields, set-aside and a National Nature Reserve. We surveyed three fields within each habitat type. The abundance of flowers was found to be a key determent of FVI abundance per field (p=0.002). Field margins/hedgerows were the most flower abundant habitat type (p=0.002) and had more than twice (235%) the FVI abundance (p=0.001) and species richness (p=0.035) per unit area than did pasture fields. Areas with long grass had greater flower abundance (p<0.001) and FVI species richness (p=0.009) than those with short grass (≤30cm). The five plants on which we recorded the greatest number of FVI were species considered to be agricultural weeds.Honey bees represented 19% of all FVI, showing that dance decoding had located a hotspot that was an important foraging location not just for honey bees but also for other types of FVI. Honey bee abundance, per transect, was strongly correlated with that of other FVI (p=0.001), particularly bumble bees (p <0.001). However, FVI groups were not found uniformly across our study site and honey bee abundance was only weakly linked to overall species richness (p=0.069).

The spatial information content of the honey bee waggle dance

In 1954, Haldane and Spurway published a paper in which they discussed the information content of the honey bee waggle dance with regard to the ideas of Norbert Wiener, who had recently developed a formal theory of information. We return to this concept by reanalyzing the information content in both vector components (direction, distance) of the waggle dance using recent empirical data from a study that investigated the accuracy of the dance. Our results show that the direction component conveys 2.9 bits and the distance component 4.5 bits of information, which agrees to some extent with Haldane and Spurway's estimates that were based on data gathered by von Frisch. Of course, these are small amounts of information compared to what can be conveyed, given enough time, by human language, or compared to what is routinely transferred via the internet. Nevertheless, small amounts of information can be very valuable if it is the right information. The receivers of this information, the nestmate bees, know how to react adaptively so that the value of the information is not negated by its low information content.

Does the Earth's magnetic field serve as a reference for alignment of the honeybee Waggle dance?

The honeybee (Apis mellifera) waggle dance, which is performed inside the hive by forager bees, informs hive mates about a potent food source, and recruits them to its location. It consists of a repeated figure-8 pattern: two oppositely directed turns interspersed by a short straight segment, the “waggle run”. The waggle run consists of a single stride emphasized by lateral waggling motions of the abdomen. Directional information pointing to a food source relative to the sun's azimuth is encoded in the angle between the waggle run line and a reference line, which is generally thought to be established by gravity. Yet, there is tantalizing evidence that the local (ambient) geomagnetic field (LGMF) could play a role. We tested the effect of the LGMF on the recruitment success of forager bees by placing observation hives inside large Helmholtz coils, and then either reducing the LGMF to 2% or shifting its apparent declination. Neither of these treatments reduced the number of nest mates that waggle dancing forager bees recruited to a feeding station located 200 m north of the hive. These results indicate that the LGMF does not act as the reference for the alignment of waggle-dancing bees.

Inner workings: Breaking down bees' dances.

Margaret Couvillon uses a protractor to measure the angle of a honey bee's waggle dance, as the insect's movements play frame by frame on a computer monitor. Image courtesy of Roger Schurch (University of Sussex, United Kingdom).

Honeybee waggle dance error: adaption or constraint? Unravelling the complex dance language of honeybees

The honeybees' (genus Apis) waggle dance is the only known example of a symbolic language in a nonprimate species. Through a complex series of stereotyped movements, a bee returning from a foraging trip can indicate to her nestmates the direction, distance and quality of a nectar, pollen or nest resource she has located. The ‘waggle’ component of the dance (indicating directional information) contains an inherent error and this error becomes smaller the further the site danced for. The imprecision in the dance effectively spreads dance followers over a patch that remains relatively constant with increasing distance to a resource. This error has been proposed to be a colony-level adaptation and to confer an advantage in the context of foraging. An alternative explanation for the error in the bees' dance is that the bees simply cannot be more precise due to constraints inherent to the dance. Here we analyse all studies to date that have investigated the bees' dance error. We conclude that the error in the honeybee waggle dance is nonadaptive and that the bees dance as best they can. © 2014 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Error in the Honeybee Waggle Dance Improves Foraging Flexibility

The honeybee waggle dance communicates the location of profitable food sources, usually with a certain degree of error in the directional information ranging from 10–15° at the lower margin. We simulated one-day colonial foraging to address the biological significance of information error in the waggle dance. When the error was 30° or larger, the waggle dance was not beneficial. If the error was 15°, the waggle dance was beneficial when the food sources were scarce. When the error was 10° or smaller, the waggle dance was beneficial under all the conditions tested. Our simulation also showed that precise information (0–5° error) yielded great success in finding feeders, but also caused failures at finding new feeders, i.e., a high-risk high-return strategy. The observation that actual bees perform the waggle dance with an error of 10–15° might reflect, at least in part, the maintenance of a successful yet risky foraging trade-off.

Incorporating variability in honey bee waggle dance decoding improves the mapping of communicated resource locations

Honey bees communicate to nestmates locations of resources, including food, water, tree resin and nest sites, by making waggle dances. Dances are composed of repeated waggle runs, which encode the distance and direction vector from the hive or swarm to the resource. Distance is encoded in the duration of the waggle run, and direction is encoded in the angle of the dancer's body relative to vertical. Glass-walled observation hives enable researchers to observe or video, and decode waggle runs. However, variation in these signals makes it impossible to determine exact locations advertised. We present a Bayesian duration to distance calibration curve using Markov Chain Monte Carlo simulations that allows us to quantify how accurately distance to a food resource can be predicted from waggle run durations within a single dance. An angular calibration shows that angular precision does not change over distance, resulting in spatial scatter proportional to distance. We demonstrate how to combine distance and direction to produce a spatial probability distribution of the resource location advertised by the dance. Finally, we show how to map honey bee foraging and discuss how our approach can be integrated with Geographic Information Systems to better understand honey bee foraging ecology.

Morphological analysis of the primary center receiving spatial information transferred by the waggle dance of honeybees

The waggle dancers of honeybees encodes roughly the distance and direction to the food source as the duration of the waggle phase and the body angle during the waggle phase. It is believed that hive-mates detect airborne vibrations produced during the waggle phase to acquire distance information and simultaneously detect the body axis during the waggle phase to acquire direction information. It has been further proposed that the orientation of the body axis on the vertical comb is detected by neck hairs (NHs) on the prosternal organ. The afferents of the NHs project into the prothoracic and mesothoracic ganglia and the dorsal subesophageal ganglion (dSEG). This study demonstrates somatotopic organization within the dSEG of the central projections of the mechanosensory neurons of the NHs. The terminals of the NH afferents in dSEG are in close apposition to those of Johnston's organ (JO) afferents. The sensory axons of both terminate in a region posterior to the crossing of the ventral intermediate tract (VIT) and the maxillary dorsal commissures I and III (MxDCI, III) in the subesophageal ganglion. These features of the terminal areas of the NH and JO afferents are common to the worker, drone, and queen castes of honeybees. Analysis of the spatial relationship between the NH neurons and the morphologically and physiologically characterized vibration-sensitive interneurons DL-Int-1 and DL-Int-2 demonstrated that several branches of DL-Int-1 are in close proximity to the central projection of the mechanosensory neurons of the NHs in the dSEG.

The Emergence of Hierarchical Structure in Human Language

We propose a novel account for the emergence of human language syntax. Like many evolutionary innovations, language arose from the adventitious combination of two pre-existing, simpler systems that had been evolved for other functional tasks. The first system, Type E(xpression), is found in birdsong, where the same song marks territory, mating availability, and similar “expressive” functions. The second system, Type L(exical), has been suggestively found in non-human primate calls and in honeybee waggle dances, where it demarcates predicates with one or more “arguments,” such as combinations of calls in monkeys or compass headings set to sun position in honeybees. We show that human language syntax is composed of two layers that parallel these two independently evolved systems: an “E” layer resembling the Type E system of birdsong and an “L” layer providing words. The existence of the “E” and “L” layers can be confirmed using standard linguistic methodology. Each layer, E and L, when considered separately, is characterizable as a finite state system, as observed in several non-human species. When the two systems are put together they interact, yielding the unbounded, non-finite state, hierarchical structure that serves as the hallmark of full-fledged human language syntax. In this way, we account for the appearance of a novel function, language, within a conventional Darwinian framework, along with its apparently unique emergence in a single species.

Working against gravity: horizontal honeybee waggle runs have greater angular scatter than vertical waggle runs

The presence of noise in a communication system may be adaptive or may reflect unavoidable constraints. One communication system where these alternatives are debated is the honeybee (Apis mellifera) waggle dance. Successful foragers communicate resource locations to nest-mates by a dance comprising repeated units (waggle runs), which repetitively transmit the same distance and direction vector from the nest. Intra-dance waggle run variation occurs and has been hypothesized as a colony-level adaptation to direct recruits over an area rather than a single location. Alternatively, variation may simply be due to constraints on bees' abilities to orient waggle runs. Here, we ask whether the angle at which the bee dances on vertical comb influences waggle run variation. In particular, we determine whether horizontal dances, where gravity is not aligned with the waggle run orientation, are more variable in their directional component. We analysed 198 dances from foragers visiting natural resources and found support for our prediction. More horizontal dances have greater angular variation than dances performed close to vertical. However, there is no effect of waggle run angle on variation in the duration of waggle runs, which communicates distance. Our results weaken the hypothesis that variation is adaptive and provide novel support for the constraint hypothesis.

ミツバチの尻振りダンスと採餌行動における効果

ミツバチの尻振りダンスと採餌行動における効果

The recruiter's excitement – features of thoracic vibrations during the honey bee's waggle dance related to food source profitability

The honey bee's waggle dance constitutes a remarkable example of an efficient code allowing social exploitation of available feeding sites. In addition to indicating the position (distance, direction) of a food patch, both the occurrence and frequency of the dances depend on the profitability of the exploited resource (sugar concentration, solution flow rate). During the waggle dance, successful foragers generate pulsed thoracic vibrations that putatively serve as a source of different kinds of information for hive bees, who cannot visually decode dances in the darkness of the hive. In the present study, we asked whether these vibrations are a reliable estimator of the excitement of the dancer when food profitability changes in terms of both sugar concentration and solution flow rate. The probability of producing thoracic vibrations as well as several features related to their intensity during the waggle phase (pulse duration, velocity amplitude, duty cycle) increased with both these profitability variables. The number of vibratory pulses, however, was independent of sugar concentration and reward rate exploited. Thus, pulse number could indeed be used by dance followers as reliable information about food source distance, as suggested in previous studies. The variability of the dancer's thoracic vibrations in relation to changes in food profitability suggests their role as an indicator of the recruiter's motivational state. Hence, the vibrations could make an important contribution to forager reactivation and, consequently, to the organisation of collective foraging processes in honey bees.

A new approach for the simultaneous tracking of multiple honeybees for analysis of hive behavior

Social activities are among the most striking of animal behaviors, and the clarification of their mechanisms is a major subject in ethology. Honeybees are a good model for revealing these mechanisms because they display various social behaviors, such as division of labor, in their colonies. Image processing is a precise and convenient tool for obtaining animal behavior data, but even recent methods are inadequate for the identification or description of honeybee behavior. This is because of the difficulty distinguishing between the large number of individuals in a small hive and their multiple movements. The present study developed a new computer-aided system, using a vector quantization method, for the identification and behavioral tracking of individual honeybees. The vector quantization method enabled separation of honeybee bodies in photographs recorded as a movie. This system succeeded in analyzing a huge number of frames quickly and can thus save both time and labor. Moreover, the system identified more than 72% of the bees in a hive and found and determined the active areas in the hive by extracting the trajectories of walking bees. In addition, useful behavioral data on the honeybee waggle dance were obtained using the present system.

Decoding information in the honeybee dance: revisiting the tactile hypothesis

The waggle dance of honeybees, Apis mellifera , is one of the most remarkable communication systems of the animal kingdom. In this study, we focused on a major gap in the understanding of this striking behaviour: the question of the sensory modality by which meaningful information is transferred from dancers to followers. We revisited the hypothesis that tactile stimuli convey information about the direction relative to gravity and the length of the waggle phase. It has long been suggested that followers use tactile stimuli arising from the wagging movements of a dancing bee to decode information in the dance. Yet, the questions of whether and to what extent such movements are mapped to the tactile experience of the followers have never been resolved. Using high-speed video techniques, we found that the higher the number of the dancer’s wagging movements, the higher the number of the followers’ antennal deflections. We also documented that most followers faced the dancers laterally and experienced a fairly regular pattern of tactile stimuli; a much smaller proportion of followers faced the dancers from behind and became the subject of a different, although still regular, pattern of tactile stimuli. From these observations, we conclude that tactile mechanosensory input from the antennae, presumably processed by neurons of the antennal joint hair sensilla and the neck hair plates, enables bees to estimate both the direction relative to gravity and the length of the waggle phase.

The honeybee waggle dance: can we follow the steps?

The honeybee (Apis mellifera) waggle dance, whereby dancing bees communicate the location of profitable food sources to other bees in the hive, is one of the most celebrated communication behaviours in the animal world. Dance followers, however, often appear to ignore this location information, the so-called dance language, after leaving the nest. Here we consider why foragers follow dances and discuss the function of the dance as a multicomponent signal. We argue that the 'dance language' is just one information component of the waggle dance and that the two terms should not be used synonymously. We propose that location information is often backup information to be used in case information acquired directly from the environment about food sources is not available, is of poor quality or is associated with unprofitable food sources.