DOI: 10.5061/dryad.t34qq
title: Data from: Colour change on different body regions provides thermal and signalling advantages in bearded dragon lizards

description: Many terrestrial ectotherms are capable of rapid colour change, yet it is
 unclear how these animals accommodate the multiple functions of colour,
 particularly camouflage, communication and thermoregulation, especially
 when functions require very different colours. Thermal benefits of colour
 change depend on an animal's absorptance of solar energy in both
 UV–visible (300–700 nm) and near-infrared (NIR; 700–2600 nm) wavelengths,
 yet colour research has focused almost exclusively on the former. Here, we
 show that wild-caught bearded dragon lizards (Pogona vitticeps) exhibit
 substantial UV–visible and NIR skin reflectance change in response to
 temperature for dorsal but not ventral (throat and upper chest) body
 regions. By contrast, lizards showed the greatest temperature-independent
 colour change on the beard and upper chest during social interactions and
 as a result of circadian colour change. Biophysical simulations of heat
 transfer predicted that the maximum temperature-dependent change in dorsal
 reflectivity could reduce the time taken to reach active body temperature
 by an average of 22 min per active day, saving 85 h of basking time
 throughout the activity season. Our results confirm that colour change may
 serve a thermoregulatory function, and competing thermoregulation and
 signalling requirements may be met by partitioning colour change to
 different body regions in different circumstances.
description: Raw beard reflectance
 values for temperature-independent experiments_Smith et al.
 2016This spreadsheet shows
 the raw reflectance spectra for the beard (throat) in its lightest and
 darkest state for each lizard measured during the temperature-independent
 experiments (social and circadian). Data for Figure S2.Raw Reflectance Values
 Temperature-Dependent Experiments_Smith et al 2016This spreadsheet shows
 the raw reflectance spectra for the beard, head, light back spot region,
 dark back spot region and chest for each lizard at the end of the 15°C and
 40°C temperature-dependent experiments. Data for Table 1, Table 2, Figure
 2 and Figure 3.Temperature-Dependent
 photo data_Smith et al. 2016This spreadsheet shows
 data obtained from linearised and equalised photographs of lizards taken
 remotely during the temperature-dependent experiments to assess the speed
 of colour change. Luminance and chroma were calculated from RGB values as
 described in the paper. Data for Figure S1, Figure S3, Figure S5, Table S2
 and Table S3.Temperature-Dependent
 reflectivity values_Smith et al. 2016This spreadsheet shows
 reflectivity values calculated from reflectance spectra taken at the end
 of each temperature-dependent colour change experiment (15C and 40C). Data
 for Figure 2, Table 1, and Table 2.Temperature-independent
 reflectivity values_Smith et al. 2016This spreadsheet shows
 reflectivity values calculated from reflectance spectra taken at the end
 of each temperature-independent colour change experiment. Data for Table 1
 and Figure S2.Biophysical Model
 Simulation_Smith et al. 2016This spreadsheet shows
 results from biophysical models used to simulate the effect of differences
 in skin reflectance on lizard warming rates. Data for Figure 4 and Figure
 S6.