Differential ability of carotenoid C4-oxygenation in yellow and red bishop species (Euplectes spp.)
Journal article, 2009

Male breeding plumages of African widowbirds and bishops (Euplectes spp.) show striking variation in carotenoid-based plumage coloration, with saturated yellow or orange-red patches of different size. Yet, from observations and experiments, agonistic signaling appears to have been a generalized sexual selection pressure for redness in the genus. Recent results show that yellow and red widowbird colors derive from distinctly different pigment profiles, and suggest that species vary in their ability to metabolize ingested carotenoids. We used reflectance spectrometry and High Performance Liquid Chromatography (HPLC) to describe the species-specific colors and plumage carotenoids of the congeneric yellow-crowned bishop (E. afer) and southern red bishop (E. orix). Results show that the yellow rump color of E. afer primarily derives from direct-deposited, dietary yellow pigments, i.e. lutein and zeaxanthin. In the red breast of E. orix, these are complemented by smaller amounts of derived red C4-keto-carotenoids: mainly α-doradexanthin, but also β-doradexanthin, canthaxanthin, astaxanthin and adonirubin. We also performed a diet supplementation experiment to investigate the relative importance of nutritional and metabolic constraints in determining the differential occurrence of C4-keto-carotenoids, and thus red plumage color, in the two species. Our results indicate that E. orix, but not E. afer, can manufacture red C4-keto-carotenoids (α-doradexanthin and canthaxanthin) from yellow dietary precursors (lutein and β-carotene).

Weaverbirds

Metabolic constraints

Sexual selection

Pigmentation

Color signaling

Author

Maria Prager

University of Gothenburg

Anette Johansson

University of Gothenburg

Staffan Andersson

University of Gothenburg

Comparative Biochemistry And Physiology B-Biochemistry & Molecular Biology

Vol. 154 373-380

Subject Categories

Biochemistry and Molecular Biology

Biological Sciences

DOI

10.1016/j.cbpb.2009.06.015

More information

Created

10/10/2017