Galápagos lava lizards (Microlophus bivittatus) respond dynamically to displays from interactive conspecific robots

  • David L. ClarkEmail author
  • Joseph M. Macedonia
  • John W. Rowe
  • Michaela R. Austin
  • Isabella M. Centurione
  • Carlos A. Valle
Original Article


In many species, outcomes of male duels determine access to females and, ultimately, male reproductive success. Ritualization of behavior in male contests can reduce the probability of injury, which benefits both contestants. Components of ritualized combat often include postures and displays that showcase a male’s quality in a sequential assessment of fighting ability. Among the most common contest acts in iguanine lizards are bobbing displays. Investigations of bobbing display dynamics often include experimental “playbacks,” in which video or robotic representations of conspecifics are presented to subjects. In most “playback” research, pre-programmed stimuli exhibit behavior that is independent of subjects’ responses, despite the fact that actual animal contests are highly interactive. In the present study, we utilized a robotic Galápagos lava lizard (Microlophus bivittatus) to investigate the importance of interaction in simulated contests under field conditions. Using a matched pairs design where each subject experienced two behavioral variants of the robotic stimulus, we tested the effect of a robot that displayed immediately following a subject’s display versus when the same robot display was postponed 30 s. Results showed that immediate response from the robot stimulated subjects to display significantly more often than when the stimulus was delayed. We speculate that subjects perceived a rapid response from their robotic contestant as being more aggressive than a delayed response. We discuss our results in light of relevant previous work, and we suggest possibilities for future research using interactive lizard robots.

Significance statement

Some of the most impressive examples of ritualized animal behavior can be observed in male contests for access to reproductive females. The use of stereotyped displays in such duels allows males to assess one another’s quality while avoiding dangerous fighting that can lead to injury. For example, males in many lizard species perform bobbing displays where contestants respond to each other in reciprocal fashion. In this study, we used a realistic lizard robot as a stand-in for a contestant in simulated contests. We found that an immediate display response by the robot to a subject’s bobbing display stimulated subjects to display significantly more often than when the robot’s response was delayed by 30 s. To our knowledge, this is the first interactive robot “playback” experiment with lizards. Future research will further explore the “rules” underlying display behavior in lizard contests.


Animal contests Assessment of fighting ability Bobbing displays Communication Lava lizard 



DLC and JMM contributed equally to this study. We thank Juan Pablo Muñoz, Administrador e Investigador, Galápagos Science Center on San Cristóbal, for permission to conduct our research with the Galápagos lava lizards. We would like to thank our reviewers for their thoughtful comments and suggestions. We dedicate this paper to the late Christopher S. Evans, a champion of the playback technique who used sound, video, and robots in experiments with a variety of animal species. Chris was particularly interested in the rules by which animal contests are conducted, and he considered interactive playbacks to be an ideal approach for uncovering those rules.


This study was funded by internal funding from Alma College.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. This was a strict observational study and no animals were directly handled or harmed during data collection, so ethical approval from an ethics committee was not required.

Supplementary material

Online Resource 1

(Video 1) Adult male Microlophus bivittatus subject exhibiting dorsal crest erection and gular inflation as it performs a volley of signature displays in response to the conspecific male robot (MP4 5956 kb)

Online Resource 2

(Video 2) A second example of an adult male Microlophus bivittatus subject exhibiting dorsal crest erection and gular inflation as it performs a volley of signature displays in response to the conspecific male robot (MP4 7501 kb)

Online Resource 3

(Video 3) Adult male Microlophus bivittatus subject performing two-bob displays as it moves toward the conspecific male robot during a trial (MP4 4099 kb)

265_2019_2732_MOESM4_ESM.jpg (2.1 mb)
Online Resource 4 (Image) Adult male Microlophus bivittatus subject observing the conspecific male robot during a trial (JPG 2117 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of BiologyAlma CollegeAlmaUSA
  2. 2.Department of BiologyFlorida Southern CollegeLakelandUSA
  3. 3.Ecology and Evolutionary BiologyUniversidad San Francisco de QuitoQuitoEcuador

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