Meeting Abstract

P1.7  Sunday, Jan. 4  Dietary fat influences carotenoid-based coloration in the American GoldfinchDietary HOOD, Wendy R*; HILL, Geoffrey E; Auburn University; Auburn University wrhood@auburn.edu

Yellow, orange and red ornamental coloration in vertebrates is often the result of carotenoid-based pigments. Carotenoid pigments cannot be synthesized by vertebrates de novo and thus carotenoids must be consumed to be expressed. Carotenoid expression in bird feathers is condition-dependent; color properties are correlated with total carotenoid intake, total food intake, and parasite load. In several bird species, males that express greater pigmentation have been shown to be preferred as mates by females, so it is assumed that females assess male pigmentation as an indicator of male condition. Carotenoids are fat-soluble pre-vitamins that are efficiently absorbed across the gut epithelium when associated with lipids in the intestinal lumen. Yet, little is known about the effect of dietary fat on carotenoid absorption and color expression in birds that express carotenoid-based ornaments. American goldfinches express bright yellow body and dark orange bill coloration that are both carotenoid based. We examined the effect of dietary fat on body and bill color expression American Goldfinches maintained throughout the molt on diets with low (7%), moderate (14%), or high fat (21%) but similar concentrations of carotenoids and total energy. Treatment has no significant effect on feather coloration, but the hue of the bill was greater (oranger) for animals consuming the 14% and 21% fat diet compared to those consuming only 7% fat. These finding suggest the fat content of diet plays a role in expression of carotenoid coloration in birds.