View in EDS

Intraspecific variation and detectability of iridescence in the dorsal coloration of a wall lizard

Saved in:
Bibliographic Details
Title: Intraspecific variation and detectability of iridescence in the dorsal coloration of a wall lizard
Authors: Abalos, J., de la Cruz, F., Pérez i de Lanuza, G., Font, E.
Contributors: Lund University, Faculty of Science, Department of Biology, Sections at the Department of Biology, Biodiversity and Evolution, Lunds universitet, Naturvetenskapliga fakulteten, Biologiska institutionen, Avdelningar vid Biologiska institutionen, Biodiversitet och evolution, Originator
Source: Journal of Zoology. 326(3):239-255
Subject Terms: Natural Sciences, Biological Sciences, Ecology (including Biodiversity Conservation), Naturvetenskap, Biologi, Ekologi, Evolutionary Biology, Evolutionsbiologi
Description: Iridescence refers to the optical property of surfaces for which the reflected wavelengths depend on viewing geometry. Although iridescence underlies some of the most striking animal colours, the sensory stimulation elicited by iridescent spectral shifts in relevant observers has seldom been explored. Wall lizards (genus Podarcis), with remarkable intraspecific colour variation and possible iridescence, offer a unique opportunity to investigate how these traits interact to shape overall colour appearance. Here, we set out to study iridescence in Podarcis liolepis in two localities in which lizards differ in dorsal coloration: the València Botanical Garden (EB) and La Murta Natural Park (LM). To determine the presence of angle-dependent reflectance, we measured dorsal coloration at three different configurations (0°, 60° and 90° angles between incident light and observer location) in 87 lizards of either sex and used visual modelling to determine their detectability when viewed by conspecifics, raptors and humans. Our results show that P. liolepis dorsal coloration varies chromatically with sex and locality and also shows iridescence (i.e. reflectance peaks at shorter wavelengths with increasing viewing angle). Lizards from EB are brown dorsally, whereas most lizards from LM, especially males, show a green dorsal background coloration, reflectance peaking at shorter wavelengths in lizards from LM compared to lizards from EB. Angle-dependent shifts in peak location are smaller in LM males than in other groups, yet iridescence appears more pronounced (i.e. larger chromatic distances between viewing angles) in LM than in EB due to greater overlap between the involved waveband and receiver cone sensitivities. Additionally, P. liolepis dorsal iridescence may be more noticeable to humans and raptors than to lizards. Our findings suggest that intraspecific colour variation influences iridescence detectability across observers, underscoring the need for objective colour quantification and visual modelling to assess the ecological consequences of animal coloration.
Access URL: https://doi.org/10.1111/jzo.70016
Database: SwePub
Description
Abstract:Iridescence refers to the optical property of surfaces for which the reflected wavelengths depend on viewing geometry. Although iridescence underlies some of the most striking animal colours, the sensory stimulation elicited by iridescent spectral shifts in relevant observers has seldom been explored. Wall lizards (genus Podarcis), with remarkable intraspecific colour variation and possible iridescence, offer a unique opportunity to investigate how these traits interact to shape overall colour appearance. Here, we set out to study iridescence in Podarcis liolepis in two localities in which lizards differ in dorsal coloration: the València Botanical Garden (EB) and La Murta Natural Park (LM). To determine the presence of angle-dependent reflectance, we measured dorsal coloration at three different configurations (0°, 60° and 90° angles between incident light and observer location) in 87 lizards of either sex and used visual modelling to determine their detectability when viewed by conspecifics, raptors and humans. Our results show that P. liolepis dorsal coloration varies chromatically with sex and locality and also shows iridescence (i.e. reflectance peaks at shorter wavelengths with increasing viewing angle). Lizards from EB are brown dorsally, whereas most lizards from LM, especially males, show a green dorsal background coloration, reflectance peaking at shorter wavelengths in lizards from LM compared to lizards from EB. Angle-dependent shifts in peak location are smaller in LM males than in other groups, yet iridescence appears more pronounced (i.e. larger chromatic distances between viewing angles) in LM than in EB due to greater overlap between the involved waveband and receiver cone sensitivities. Additionally, P. liolepis dorsal iridescence may be more noticeable to humans and raptors than to lizards. Our findings suggest that intraspecific colour variation influences iridescence detectability across observers, underscoring the need for objective colour quantification and visual modelling to assess the ecological consequences of animal coloration.
ISSN:09528369
14697998
DOI:10.1111/jzo.70016