RoboBee: A Biomimetic Honeybee Robot for the Analysis of the Dance Communication System

Abstract

This thesis describes the development of a honeybee robot for the analysis of the dance communication system of the European Honeybee (Apis Mellifera). “RoboBee” is a tool to find out which of the stimuli produced by a dancing bee are actual signals, i.e. which stimuli are used by the follower bees to decode the message. This dissertation comprises six chapters: First, I introduce the reader to the motivation, scope and structure of the dissertation. Then I give a detailed overview of the key aspects of this thesis. Beginning with a short introduction to the history of waggle dance research, I report current views on the function and mechanism of the dance. In this chapter I also report on open questions in our understanding of the communication process. In the second part of the chapter, I list similar systems that were used to imitate the waggle dance. I close the chapter by report on more general examples of robots in behavioral biology. The following chapter contains description of own preliminary work and experiments prior to building RoboBee. First, I introduce basic methods for keeping bees under experimental conditions. I outline lighting and video recording setups that I used in many works that follow up in later parts of the thesis. Then I specify details of a computer vision algorithm that I developed to track waggle dances in video recordings. Subsequently, I analyze waggle dance trajectories statistically, concluding with a computer model of the dance motion. In the last section, I describe experimental tests for the characterization of the sensory capabilities of honeybees. After this analytical part, I give a detailed overview of the mechanics, the electronics and the software of RoboBee in a separate chapter. I review shortly a number of prototypes and conclude with the description of the final system. Each stimulus produced by the robot is characterized and compared to reference cues in the natural system. The chapter is concluded by validating and discussing RoboBee’s components. The ultimate validation is a test in live bee colonies. In the summers 2009 – 2011 I conducted experiments to validate different functions of RoboBee. A major part of the thesis is concerned with all experimental field trials conducted in this period of time. The first experiments lead to the identification of materials that are accepted in live honeybee colonies. Following experiments address RoboBee’s ability to recruit trained and naïve bees. Each description of the experiment’s scope and setup is followed by the presentation of the results and their discussion. The final results of the summer 2011 – the following behavior of foragers and their ensuing flights - are statistically evaluated in detail by comparing natural dance following behavior with that shown with RoboBee’s dances. Flight traces of bees that displayed extensive following behavior are presented. I conclude this dissertation by reviewing the achievements and their implications. I discuss the significance of the results and give an outlook of future experiments and possible improvements to RoboBee.