Carotenoid-based colours reflect the stress response in the common lizard.
Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR.
Fitze
Patrick S
PS
Museo Nacional de Ciencias Naturales CSIC, Madrid, Spain. patrick.fitze@mncn.csic.es
Cote
Julien
J
San-Jose
Luis Martin
LM
Meylan
Sandrine
S
Isaksson
Caroline
C
Andersson
Staffan
S
Rossi
Jean-Marc
JM
Clobert
Jean
J
D000818:Animals; D002338:Carotenoids / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003116:Color; D003345:Corticosterone / Q000097:blood; D005260:Female; D008116:Lizards / Q000502:physiology*; D008297:Male; D010860:Pigments, Biological / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D013312:Stress, Physiological
D010860:Pigments, Biological; D002338:Carotenoids; D003345:Corticosterone