Hidden Bills, Mallards, Anas platyrhynchos, Hortus Botanicus, Amsterdam, The Netherlands
It was chilly. Our Pair of Ducks was resting after foraging and in order to preserve body heat and relieve neck muscles they'd tucked feather-naked yellow bills under their warm-feathered wings. Sleeping they keep one eye open to warn them in case I'd come too close for comfort. The coloring of green head and blue wing patches (called 'specula' in ornithological parlance) is beautiful. That coloring is not caused by pigmentation. Pigments 'color' by absorbing light. But the green and blue of our Mallard are produced by special nanostructures in those feathers that reflect special wavelengths of light.
Hidden Bills, Mallards, Anas platyrhynchos, Hortus Botanicus, Amsterdam, The Netherlands
It was chilly. Our Pair of Ducks was resting after foraging and in order to preserve body heat and relieve neck muscles they'd tucked feather-naked yellow bills under their warm-feathered wings. Sleeping they keep one eye open to warn them in case I'd come too close for comfort. The coloring of green head and blue wing patches (called 'specula' in ornithological parlance) is beautiful. That coloring is not caused by pigmentation. Pigments 'color' by absorbing light. But the green and blue of our Mallard are produced by special nanostructures in those feathers that reflect special wavelengths of light.