American Journal of Primatology 68:1054–1067 (2006) RESEARCH ARTICLE Perceptual Considerations in the Use of Colored Photographic and Video Stimuli to Study Nonhuman Primate Behavior CORRI WAITT 1,2Ã AND HANNAH M. BUCHANAN-SMITH 1 1 Scottish Primate Research Group, Department of Psychology, University of Stirling, Stirling, United Kingdom 2 Animal Behaviour Group, Department of Zoology, University of Oxford, Oxford, United Kingdom The use of photographs, slides, computerized images, and video to study behavior is increasingly being employed in nonhuman primates. However, since these mediums have been designed to simulate natural coloration for normal trichromatic human vision, they can fail to reproduce color in meaningful and accurate ways for viewers with different visual systems. Given the range of color perception that exists both across and within different species, it is necessary to consider this variation in order to discern the suitability of these mediums for experimental use. Because of the high degree of visual similarity among humans, Old World monkeys, and apes, the use of photographic and video stimuli should be acceptable in terms of replicating naturalistic coloration and making noticeable color manipulations. However, among New World primates and prosimians, there exists a considerable degree of variation in color perceptual abilities depending on the species, sex, and allelic combination of the animals involved. Therefore, the use of these mediums to study behavior is problematic for these species, and should be done with caution. Am. J. Primatol. 68:1054–1067, 2006. r 2006 Wiley-Liss, Inc. Key words: primates; color; vision; experimental methods INTRODUCTION The use of photographs, slides, computerized images, and video to study animal behavior is becoming increasingly popular [reviewed by D’Eath, 1998]. However, some researchers have major reservations about their use because of discrepancies between human and nonhuman visual systems [e.g., D’Eath, 1998; Fleishman et al., 1998; Fleishman & Endler, 2000]. Because these mediums are constructed for human viewing, they may fail to reproduce color in meaningful and accurate ways for nonhuman viewers. These criticisms are Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ajp.20303 Received 17 November 2005; revised 13 January 2006; revision accepted 14 January 2006 Contract grant sponsor: Department of Psychology, University of Stirling. Ã Correspondence to: Corri Waitt, John Krebs Field Station, University of Oxford, Wytham OX2 8QJ, UK. E-mail: corri.waitt@zoo.ox.ac.uk r r 2006 Wiley-Liss, Inc.