Studying Primate Color: Towards Visual System-dependent Methods

Abstract

Primates exhibit a striking diversity of colors and patterns in their pelage and skin markings, used in functions as diverse as camouflage to sexual signaling. In studying primate colors, it is important to adopt approaches not based on human assessment wherever possible, and that preferably take account of the visual system of the appropriate receiver(s). Here, we outline some of the main techniques for recording the colors exhibited and encountered by primates, including the use of digital photography and reflectance spectrometry. We go on to discuss the main approaches for analyzing the data obtained, including those not linked to a particular visual system, such as direct analyses of reflectance spectra. We argue that researchers should strive for analyses based on the visual system of the relevant receiver, and outline some of the main modeling approaches that can be used, such as color space and discrimination threshold modeling. By analyzing color measures with respect to specific visual systems, field studies can link behavioral ecology to the visual and cognitive sciences, and move toward descriptions of signal information content that incorporate elements of receiver psychology. This in turn should lead to a greater understanding of the detection and interpretation of signals by receivers, and hence their likely use in decision making.

Color in competition contexts in non-human animals

“…More sophisticated methods include spectrometry (Renoult et al, 2011;Sumner & Mollon, 2003). Future studies should also, ideally, account for the species' visual system (Stevens, Stoddard, & Higham, 2009), as well as the visual environment in which a signal occurs, to obtain a primate's eye view of their world. For example, theory predicts that red signals in forest shade should include blue or blue-green, to be most conspicuous (Thery, 2006).…”

Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators

“…[16][17][18][19][20]. In the last decade, this multiband imaging system, originally designed for remote sensing, has been applied largely in studying human color vision (41-46) and animal color communication (47).…”

“…Previous investigations of camouflage using image analysis (including spatial filtering and edge detection) provided insights into the mechanisms of visual perception of predators (13,14), yet these studies suffer from the inability to assess the effectiveness of camouflage in the visual space of predators (15). Recent studies using digital photography in conjunction with color space modeling have examined body coloration in both spatial and spectral domains (16)(17)(18)(19)(20). In the present study, we exploit unique imaging technology [hyperspectral imaging (HSI)] (Fig.…”

Hyperspectral Imaging of Cuttlefish Camouflage Indicates Good Color Match in the Eyes of Fish Predators

“…The potentially optimal solution for characterization of both spatial and spectral information in studying animal communication is the use of multispectral or hyperspectral imaging systems (but see a few exceptions in 16,[17][18][19][20]. In the last decade, this multiband imaging system, originally designed for remote sensing, has been applied largely in studying human color vision (41)(42)(43)(44)(45)(46) and animal color communication (47).…”

“…Previous investigations of camouflage using image analysis (including spatial filtering and edge detection) provided insights into the mechanisms of visual perception of predators (13,14), yet these studies suffer from the inability to assess the effectiveness of camouflage in the visual space of predators (15). Recent studies using digital photography in conjunction with color space modeling have examined body coloration in both spatial and spectral domains (16)(17)(18)(19)(20). In the present study, we exploit new imaging technology (HyperSpectral Imaging, HSI; Fig.…”