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Tag Archive | "Blue Jays"

Colors of Spring

Ranger Steve’s Nature Niche By Ranger Steve Mueller

We wait. It is coming. When? Anticipation of green leaves, first garden flowers, butterfly wings, and changing bird feathers from dull winter hues to spring’s festive brightness are all on the way. We can’t wait but we must. 

Unlike many birds who lose their color during the winter, Northern Cardinals retain their bright red feathers. Photo by Hari Krishnan (https://creativecommons.org/licenses/by-sa/4.0)]

American Goldfinches are displaying patches of yellow that will replace the olive feathers from last fall’s molt. A black cap on males will become prominent. Black wing feathers with white markings will contrast with the sunshine yellow of summer body feathers. Male Northern Cardinals have maintained a bright red all winter. Blue Jays display crystal blues. White-breasted Nuthatches show a splash of orange on the belly under the tail.

Bird colors are often ephemeral pigments that serve survival and breeding functions. The genetic bases of color is sometimes structural instead of pigmental. Diet can cause color variation. House Finch males typically have red feathers but yellow develops instead if they do not eat adequate carotenoids in their diet during feather development. They need a mother to remind them to eat their carrots. Plants and insects often contain the needed carotenoids. 

Melanin is responsible for black, brown, and earth tones. Carotenes provide yellow, orange, and red that please our eyes. Joyful blues on Eastern Bluebirds, Indigo Buntings, and Blue Jays are structural colors instead of pigments. 

Colors provide a variety of functions in bird nature niches. During the non-breeding season, the bright displays used in breeding season to court females or to claim territory could draw the attention of predators when trees are bare. Having bright colors is not as dangerous during breeding season when birds can hide among tree foliage. Birds advertise their presence with songs to females and other males from secluded perches where they can show off bright colors to her or use them to threaten other males in territorial disputes. Some colorful birds sing from exposed perches but many, like warblers and vireos, sing more secretively in the thick tree canopy. 

Why Northern Cardinals stay bright red all year remains a mystery to me. It would seem changing to the rusty color of females during the fall molt would be advantageous. People feeding birds ask me why predators, like the Cooper’s Hawks, always have to take their cardinals? They wish they would pick on duller colored birds. I am sure they take both but we notice the bright red feathers scattered on the ground. 

Blue color appears when feather structure splits short light waves from longer reds and yellow light waves. The blue is reflected outward while reds and yellows are absorbed by melanin and remain hidden to our eyes.

White feathers lack pigments and strength. We notice the new black feathers in fall on European Starlings have white edges creating a spotted appearance. During the winter the white tips wear off and the birds become shiny black by spring. Pigment gives feathers greater strength and durability.

Feather pigments aid important ornamental breeding displays, territory establishment, protective camouflage, and help with heat absorption.

Perhaps your heart has been momentarily stopped when a Ruffed Grouse burst into the air from vegetation near your feet. How often have we walked past birds that remained hidden with stillness? They have many essential behaviors for survival aided by color. 

Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at odybrook@chartermi.net – Ody Brook Nature Sanctuary, 13010 Northland Dr. Cedar Springs, MI 49319 or call 616-696-1753.

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