2007/06/18 by Kevin J. McGraw, Matthew B. Toomey, Paul M. Nolan +3 · 1 voice · 4 citations
Agricultural and Biological Sciences · Environmental Science · Immunology and Microbiology · #Animal Behavior and Reproduction #Amphibian and Reptile Biology #Bird parasitology and diseases
paper · doi:10.1111/j.1600-0749.2007.00386.x
openalex publication_date 2007/06/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Appendix S2. Light absorbance (λmax, or wavelengths at peak absorbance) and retention times (Rt), as determined by high-performance liquid chromatography, for authentic pterin, purine, flavin, and papiliochrome standards as well as the yellow penguin pigments. Figure S1. (A) Color photographs of the colorful plumage regions from all six studied penguin species; (B) Confocal microscopy images revealing the presence of small crystals (or "reflecting platelets") in the yellow feathers of all study species. Other feather regions subtly glow in these images because white keratin also fluoresces dimly. For comparison, we imaged red, carotenoid-based house finch (Carpodacus mexicanus) feathers, which also exhibited background, keratin-generated fluorescence but lacked crystalline structures (not shown). Interimage differences in fluorescence intensity are not biologically relevant and are due to alterations made to microscope sensitivity to maximize contrast of imaged structures. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.