Plant Pigments in Birds
I recently found out that all of the yellow pigment in the hooded oriole’s feathers is not synthesized or modified by the bird itself! This pigment, lutein, is made by plants (Friedman et al. 2014). Lutein is a yellow pigment in plants that converts light to heat. It does this when there is too much light hitting a leaf, and the sun exposure is too direct for the chloroplasts to handle (Dall’Osto et al. 2006). Lutein cannot be synthesized by animals, so they must obtain it by eating plants. Lutein gets concentrated in the retina of both humans and wood ducks, helping to filter blue light, reducing glare, and functioning like sunglasses (Kijlstra et al. 2012)!
