Carotenoid Access, Nutritional Stress, and the Dewlap Color of Male Brown Anoles

Carotenoids are integumentary colorants that must be ingested by vertebrates to be used as colorants. In many studies of fish and birds, carotenoid color serves as an indicator of foraging success, nutritional state, or parasite load. The dewlap of male Brown Anoles (Norops sagrei) contains the carotenoid pigments lutein and zeaxanthin. We performed a two-factor experiment to determine the effects of nutritional stress and xanthophyll supplementation on male dewlap color in N. sagrei. We tested the hypotheses that dewlap color is dependent on access to carotenoids and good nutrition. Contrary to our predictions we found no significant differences among groups of anoles that were either supplemented or not supplemented with carotenoids. Similarly, post-experimental dewlap spectral variation did not differ significantly among groups that were provided a standard or reduced diet. These findings demonstrate that dewlap color of adult male Brown Anoles does not change in response to food access or carotenoid supplementation.