DOI: 10.5061/dryad.bp67v
title: Data from: Proximate mechanisms of colour variation in the frillneck lizard: geographical differences in pigment contents of an ornament

description: Animal coloration has evolved in contexts such as communication,
 camouflage, and thermoregulation. Most studies of animal coloration focus
 on its adaptive benefits, whereas its underlying mechanisms have received
 less attention despite their potential influence on adaptive benefits. In
 fish and reptiles, for example, colour variation from yellow to red can be
 produced by carotenoid and/or pteridine pigments, which differ
 dramatically in the way they are obtained (carotenoids through diet and
 pteridines synthesized de novo). Hence, potential adaptive benefits could
 differ greatly depending on the relative contribution to coloration of
 different pigments. In the present study, we investigate the mechanisms
 underlying colour variation in the frill of the Australian frillneck
 lizard (Sauropsida: Chlamydosaurus kingii). Frill colour varies between
 populations across the species' range (red, orange, yellow or white).
 We argue that this geographical variation results from different
 concentrations of carotenoids and pteridines in the frill. Frill
 carotenoid concentrations were lower in eastern populations (yellow and
 white forms), and pteridines were present only in the red and orange
 forms, thereby explaining their redder hues. The observed geographical
 variation in frill carotenoids suggests variation in carotenoid
 availability across the species' range, which is backed up by the
 finding that plasma carotenoid concentrations were higher in the red
 (western) compared to the yellow (eastern) form. Although no correlations
 were found between individual colour measurements, frill pigments and
 plasma carotenoids, our results suggest that selective pressures vary
 across the species' range and we speculate that predation pressures
 and/or intrasexual signalling context differ between forms.
description: spec
 NTZip
 archive containing all the spectral files for individuals of the orange
 form of the frillneck lizard. To be analysed with the script 'script
 BJLS colour contrasts.R'.spec
 QLDZip archive containing
 spectral files for individuals of the yellow and white forms of the
 frillneck lizard. To be analysed with the script 'script BJLS colour
 contrasts.R'.spec
 WAZip
 archive containing spectral files for individuals of the red form of the
 frillneck lizard. To be analysed with the script 'script BJLS colour
 contrasts.R'.Colour contrasts WA-QLD
 from 4 pop dataColour contrasts values
 for individuals of the red and yellow form, as calculated in the
 'script BJLS colour contrasts.R'. These data are used in the
 script 'script BJLS correlations carot plasma skin
 colour.R'.Frilly carot plasma skin
 colour dataFile containing plasma
 pigment concentrations, skin pigment concentrations and colour contrasts.
 Analysed using the script 'script BJLS correlations carot plasma skin
 colour'.irradianceIrradiance data for visual modelling.spectral_sensitivitiesLizard spectral sensitivities used for the visual modelling.script BJLS colour contrastsR script to calculate the colour contrasts for the four colour forms of the Frillneck lizard.script BJLS correlations carot plasma skin colourR script used to look at the correlations between plasma carotenoid concentrations, skin pigment concentrations and colour contrasts.