Digital video playback and visual communication in lizards

• Published in: Animal behaviour 2002-05, Vol.63 (5), p.879-890
• Main Authors: Ord, Terry J., Peters, Richard A., Evans, Christopher S., Taylor, Alan J.
• Format: Article
• Language: English
• Subjects: Animal behavior; Animal communication; Animal ethology; Biological and medical sciences; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; General aspects; Males; Psychology. Psychoanalysis. Psychiatry; Reptiles & amphibians; Vertebrates: nervous system and sense organs; Video
• ISSN: 0003-3472; 1095-8282
• DOI: 10.1006/anbe.2001.1983

Experimental analyses of dynamic visual signals have to overcome the technical obstacle of reproducing complex motor patterns such as those found in courtship and threat displays. Video playback offers a potential solution to this problem, but it has recently been criticized because of sensory differences between humans and nonhuman animals, which suggest that video stimuli might be perceived as deficient relative to live conspecifics. Quantitative comparisons are therefore necessary to determine whether video sequences reliably evoke natural responses. Male Jacky dragons, Amphibolurus muricatus, compete for territories using complex displays delivered in a rapid stereotyped sequence. We evaluated video playback as a technique for studying this visual signal. Digital video sequences depicting a life-sized displaying male were indistinguishable from live male conspecifics in the rate and structure of aggressive displays evoked. Other measures of social behaviour suggested that video stimuli were more effective in this context. Lizards produced significantly more appeasement displays and had higher rates of substrate licking and locomotor activity in response to video playback than to confined male opponents, which failed to produce aggressive displays. Lizards tracked temporal changes in the display rate of video stimuli and were also sensitive to individual differences in morphology and behaviour between video exemplars. These results show that video stimuli are appropriate for the experimental analysis of Jacky dragon aggressive displays. We compare the potential shortcomings of video playback with those of other techniques and conclude that no approach offers a panacea, but that several have complementary characteristics. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.