endler-colorchangefor-2016.pdf (625.56 kB)
Color change for Thermoregulation versus camouflage in free-ranging lizards
journal contribution
posted on 2016-12-01, 00:00 authored by K R Smith, V Cadena, John EndlerJohn Endler, M R Kearney, W P Porter, D Stuart-FoxAnimal coloration has multiple functions including thermoregulation,
camouflage, and social signaling, and the requirements
of each function may sometimes conflict. Many terrestrial ectotherms
accommodate the multiple functions of color through color change.
However, the relative importance of these functions and how colorchanging
species accommodate themwhen they do conflict are poorly
understood because we lack data on color change in the wild. Here, we
show that the color of individual radio-tracked bearded dragon lizards,
Pogona vitticeps, correlates strongly with background color and
less strongly, but significantly, with temperature. We found no evidence
that individuals simultaneously optimize camouflage and thermoregulation
by choosing light backgrounds when hot or dark backgrounds
when cold. In laboratory experiments, lizards showed both UV-visible
(300–700 nm) and near-infrared (700–2,100 nm) reflectance changes
in response to different background and temperature treatments, consistent
with camouflage and thermoregulatory functions, respectively,
but with no interaction between the two. Overall, our results suggest
that wild bearded dragons change color to improve both thermoregulation
and camouflage but predominantly adjust for camouflage, suggesting
that compromising camouflage may entail a greater potential
immediate survival cost.
camouflage, and social signaling, and the requirements
of each function may sometimes conflict. Many terrestrial ectotherms
accommodate the multiple functions of color through color change.
However, the relative importance of these functions and how colorchanging
species accommodate themwhen they do conflict are poorly
understood because we lack data on color change in the wild. Here, we
show that the color of individual radio-tracked bearded dragon lizards,
Pogona vitticeps, correlates strongly with background color and
less strongly, but significantly, with temperature. We found no evidence
that individuals simultaneously optimize camouflage and thermoregulation
by choosing light backgrounds when hot or dark backgrounds
when cold. In laboratory experiments, lizards showed both UV-visible
(300–700 nm) and near-infrared (700–2,100 nm) reflectance changes
in response to different background and temperature treatments, consistent
with camouflage and thermoregulatory functions, respectively,
but with no interaction between the two. Overall, our results suggest
that wild bearded dragons change color to improve both thermoregulation
and camouflage but predominantly adjust for camouflage, suggesting
that compromising camouflage may entail a greater potential
immediate survival cost.
History
Journal
American naturalistVolume
188Issue
6Pagination
668 - 678Publisher
University of Chicago PressLocation
Chicago, Ill.Publisher DOI
ISSN
0003-0147eISSN
1537-5323Language
engPublication classification
C Journal article; C1 Refereed article in a scholarly journalCopyright notice
2016, University of ChicagoUsage metrics
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