Motion Picture and Videotape Analysis of Behavior

Abstract

Film and videotape are useful tools in the analysis of animal behavior. A camera can capture actions that evade an observer's eye; films taken at high speeds can be viewed at slow rates to capture actions too fast to be viewed at a normal pace. Single-frame analysis can be employed stop-motion in order to permit detailed analysis of rapid behavior patterns. Time-lapse photography and videotape are useful in recording behaviors and interactions that take place infrequently or over prolonged periods. Finally, film and videotape can be viewed repeatedly, allowing the observer to concentrate on the behavior of several animals or separate events at a particular time, or on different body parts of a single animal during any particular behavior. An observer unaided by the camera may have difficulty concentrating on more than a single animal or body part at one time. Films and videotapes can be used to determine behavior patterns via a method known as single-frame analysis. This does not necessarily involve the viewing of every single frame as the name implies, but merely recording the position of particular body parts, entire animals, or even the behavior of an animal at constant intervals. This technique has been exploited in the study of the species-specific display action patterns (DAP) of iguanid lizards (Carpenter and Ferguson 1977; cf. Carpenter this volume) (fig. 1). The species-specific DAP of a lizard is employed as a social signal during encounters with conspecifics and may involve fighting, territoriality, or courtship. The DAP involves specific sequences of head-bobs and push-ups that occur over specific time intervals. These are of paramount importance in many kinds of lizards in the recognition of species, sex and probably individuals. Sophisticated equipment is available for timemotion analysis, for example, the Vanguard Motion Analyzer (Vanguard Instrument Corporation, Long Island, NY). Although easy and convenient to use, this equipment is costly. A simple, less expensive, laboratory set-up for time-motion analysis can be constructed (fig. 2). A projection screen should have a grid drawn on it for the analysis of behavior. For videotape analysis a transparent