Meeting Abstract

P2.30  Friday, Jan. 4  Seasonal Costs Of Carotenoid Ingestion In Songbirds With Extensive Carotenoid-Based Plumage Coloration: Are Carotenoids Detrimental? HUGGINS, KA*; NAVARA, KJ; HILL, GE; MENDONCA, MT; Auburn University; University of Georgia; Auburn University; Auburn University huggika@auburn.edu

Although there is extensive literature addressing the beneficial effects of carotenoids as antioxidants and immune enhancers, there are also studies that indicate that high doses of carotenoids may actually have a toxic effect. Songbirds with extensive, carotenoid-based plumage tend to maintain high levels of circulating carotenoids in plasma, which could represent a potential tradeoff between maintaining brightness at the expense of carotenoid-related toxicities. To test this hypothesis, we maintained American goldfinch males on either a high (n=40) or a low (n=40) dose of lutein/zeaxanthan treatment for 60 days for two years during the time of molt. We took blood samples from animals before, during, and after supplementation, and analyzed the samples for baseline corticosterone as a measure of physiological stress and creatine kinase (CK) as a measure of muscle degradation. Additionally, we tested muscle function using a vertical ascent test, a novel technique that tests the performance capability of the pectoral muscles in birds. We found that CK levels were significantly higher 60 days after the end of supplementation in animals receiving a high dose of dietary carotenoids (p = 0.01), indicating the presence of muscular degradation in these birds. Birds in the same treatment had significantly reduced flight elevations at the same time as the significant elevation in CK levels (p=0.01) at the time creatine kinase levels were elevated indicating that there was a direct effect between increased carotenoid intake, increased creatine kinase levels and outward physical ability.