The indigo bunting perching in sunlight is like a sapphire with wings. Glistening intensely blue, it is a gem of a bird.
A bird watcher’s attention is first drawn to the bird by its distinctive song, which is usually delivered as a long series of paired notes, sometimes characterized by a mnemonic such as “sweet-sweet” or “chew-chew.”
One researcher found that the male bunting sings at the rate of five songs a minute for an hour at a time, and “not less than two thousand times a day.”
Of course a bird of such beauty wants to be seen, so he broadcasts his song from the most conspicuous perch available. To show to best advantage, it must be in bright sunlight. When the bird is seen in shadows, it often appears to be black. So, how does such a brilliant bird change color instantly and so completely?
The colors of birds are manifested in three ways.
Some, such as the cardinal’s bright red, result from pigments in their feathers. The most common pigments are melanins, which produce the brown and black colors of so many owls, hawks and shorebirds, as well as such game birds as quail and grouse. The pigments that give cardinals, flamingos and scarlet tanagers their color are called carotenoids, named for the pigment found in carrots.
Many of the brightest colors found in birds result not from pigments, but from iridescence. Iridescence is created by the refraction of light caused by microscopic structures that act as prisms in the feathers.
The bright colors of certain hummingbird feathers are good examples of this phenomenon, and it’s why the ruby-throat’s red chin and shimmering green body are so brilliant when this bird is in the sun but appear drab when it’s perched in the shade.
Some colors in birds are neither pigments nor iridescence. The bunting’s blue coloration results from feather structures in which light waves of blue are reflected from a layer of cells in the birds’ feathers. The blue in bird feathers such as bluebirds and blue jays, as well as the indigo bunting, is never a result of blue pigment.
If it were named for its preferred habitat, as are the pine warbler, saltmarsh sparrow and cactus wren, this bird might have been named the blackberry bunting. Such is its preference for weed fields and briar patches. But its sparkling color is its chief feature and so indigo bunting it is.
The female bunting is a study in beige, and her plainness is a key to identifying her. Wing bars and breast streaks often important field marks that help distinguish some birds from others, but on the female indigo bunting, these are faint.
The bird that’s most likely to be confused with the bunting is the blue grosbeak. These two occupy the same habitat, and the grosbeak is a similar shade of blue; however, it wears a rust-colored wing bar that stands out against the blue and is twice the size of the bunting by weight.
This bird soon will travel a thousand miles to its wintering residence in Mexico, Belize or Cuba where it can be seen in numbers from a few to a thousand birds.
Indigo buntings reside in our area from late April through early October, so you have another month to see this bejeweled bird before it heads south.
Among the best places to find this bird are the Muddy Creek Greenway, the Yadkin River Nature Trail’s meadow at Tanglewood Park, and the fallow fields along Bethania’s Black Walnut Bottoms Trail.
Other birds that are common in this habitat are the goldfinch, song sparrow, towhee and common yellowthroat.
To learn more about colors in birds, visit academy.allabout birds.org/how-birds- make-color.