Spring swiftly turned into summer, and the local birds are putting on their best suits as they molt their feathers in time for the breeding season. I've always been in awe of birds - jealous of their ability to fly away when life gets rough, their beautiful colors, and their incredible diversity. Over 10,000 species of birds thrive on every continent - that's more than we can say. I am always mesmerized by soaring raptors, the hovering hummingbirds, and the songbirds that flit from branch to branch. How do they move so quickly and gracefully? Why are they so colorful or camouflaged? The answer to all my bird thoughts and questions lies with their feathers - the epitome of beauty and function.
Feathers are made up of keratin, similar to human hair. Like other animals, they contain compounds like melanin and other pigments that give feathers their color. Eumelanin produces gray and black colors, while pheomelanin produces shades of warm colors like duller yellows and red. Carotenoids are different pigments that produce brilliant, vibrant shades of yellow and red. The brightness of these colors is dependent on the age, sex, and diet of the individual.
An array of red-tinged birds were enjoying a wildlife drinker at Borderlands Wildlife Preserve this spring. While they may seem like bright red stop signs for predators, saying "Stop! I'm right here! Eat me!" they remain quite inconspicuous. We often hear Northern cardinals along the path in Sabino Canyon long before we see them, and as soon as we catch a glimpse, they disappear just as quickly back into the bushes.
Most often, the brightly colored male birds are trying to woo their female counterparts, who often sport camouflaging brown and gray plumage. Their vibrant pigments help attract mates - the brighter, the better. Usually, this is a sign that the male is healthy and can provide for their offspring.
What about blue pigments? The blue we often associate with jays is caused by the structure of molecules within their feathers. This unique structure absorbs all wavelengths of light except for blue, making these birds appear in different shades of blue depending on the angle you view them from as the light is refracted outwards.
What about birds that don't use vivid feathers to attract a mate? Species like the common raven employ other methods, like their impressive vocality. Ravens use a wide range of sounds to mimic and communicate with each other, which makes them very sociable. Their courtship ritual involves flying close together, cooing, and preening each other's feathers. Preening refers to the cleaning and straightening of their feathers, which they do to themselves and others. This is critical in maintaining the structure and function of each feather, and all birds spend a portion of their day dedicated to preening.
A raven's all-black feathers are a result of eumelanin present in their feathers. This type of melanin produces gray and black shades and is structurally stronger than other pigments. This makes black feathers coarser and stiffer, which is why you can hear a raven flapping its wings quite loudly compared to other birds. Many woodpeckers have black feathers to protect them from their frequent contact with tree bark, and many far-flying migratory birds have black wing tips, like Snow Geese. The melanin strengthens the feathers and keeps them from wearing out as quickly.
Feathers are made up of a series of interconnecting, microscopic barbs and barbules. They are beautifully simple, and a marvel of evolution, and their color can tell you a lot about a bird's social behavior, diet, and habitat.
Birds play essential roles in almost every ecosystem, as their feathers have allowed them to diversify into thousands of species and inhabit every corner of the world. Patagonia, Arizona is home to an impressive rainbow of birds: our beloved black-cloaked vultures, ghostly white barn owls, colorful painted buntings - and everything in between.
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