Carotenoids Bolster Birds' Feather Color

In many species of birds, bright, colorful feathers serve as a signal of vitality and as a result the more vibrant birds often are more successful at attracting mates. In species such as house finches, flamingos, scarlet ibises and Northern cardinals, their colorful feathers are the result of a diet rich in carotenoids.

Carotenoids are a class of organic pigments that are produced by plants. These red, yellow, and orange pigments help plants to absorb light energy for photosynthesis and prevent degradation of chlorophyll. But the advantages of carotenoids are not restricted to the plants that synthesize them. Animals that eat plants rich in carotenoids enjoy numerous benefits from these compounds as well.

Carotenoids function as antioxidants and boost the immune system. They serve as coloring agents in many organisms. Numerous species of birds (for example, Northern cardinals, scarlet ibises, house finches, flamingos) feast on carotenoid-rich foods. As a result individuals with the best diets are the most colorful and potentially more successful at attracting mates.

Now, scientists from Arizona State University are investigating several other ways carotenoids might be beneficial to birds. The team, lead by Professor Kevin McGraw, is studying house finches, mallards, and northern pintails.

"Carotenoids play fascinating and multifaceted roles in the lives of animals. For years, we have known that, as antioxidants, they boost human health and, as colorants, make birds colorful and sexually attractive. Now, we are blending as well as expanding these paradigms and studying how consumption of carotenoids can improve or 'tune' their color vision, promote the health of offspring as they develop in the egg, and possibly improve male sperm quality." ~ Kevin McGraw, Arizona State University.

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