Deep blue plumage is a captivating sight across North America. This striking coloration stands out because, unlike reds and yellows, a true blue pigment does not exist in the feathers of most birds. The visual effect of blue is instead a trick of the light, created through specialized feather structures that selectively reflect blue wavelengths. North America is home to several iconic species, from the far-ranging jays to the smaller songbirds. These species have adapted to diverse environments, making the brilliant blue flash a possibility in nearly every region.
Primary Blue Bird Species of North America
The Eastern Bluebird is a small songbird. The male exhibits a bright blue head, back, and wings, contrasted by a rusty-orange throat and chest that fades into a white abdomen. Its western counterpart, the Western Bluebird, often displays a more extensive blue area on the back and a partial chestnut-colored back patch, while the female appears duller and grayer. The Mountain Bluebird is perhaps the bluest, with the male often appearing entirely sky-blue, lacking the characteristic rusty chest of the other two species.
The Blue Jay is a larger species, recognized by its prominent crest and a striking black necklace encircling its white throat. This jay is primarily found in eastern North America and has a stout body that can reach nearly a foot in length. In the West, the Steller’s Jay shares the crest but features a dark, almost black head and a body of deep indigo blue.
The Indigo Bunting and the Lazuli Bunting are two smaller species known for their intense blue breeding plumage. The male Indigo Bunting appears almost entirely deep blue in the summer, though the color is structurally produced and can look black in poor light. The Lazuli Bunting, found in western North America, is distinguished by its bright turquoise head and back, a white belly, and a vibrant chestnut band across its chest.
The Biological Mechanism of Blue Feathers
The blue coloration seen in these birds is a product of structural color, not pigmentation. Unlike colors like red or yellow, which are created by pigments deposited in the feather, blue is derived from the physics of light scattering. Feathers contain an outer layer of keratin surrounding a spongy layer composed of tiny air pockets and protein structures.
When white sunlight hits the feather, the microstructure of the spongy layer scatters the shorter, blue wavelengths of light in all directions, making the feather appear blue. Longer wavelengths, such as red and yellow, pass through the spongy layer to be absorbed by melanin granules located beneath the structure. This absorption intensifies the perceived blue color. Because the color depends on the physical structure and the angle of light, a blue feather viewed with light passing through it will often look brownish due to the underlying melanin.
Geographic Distribution and Habitat Types
The Eastern Bluebird is the most widespread of the bluebirds, occupying open woodlands, orchards, and farmland habitats east of the Rocky Mountains. The Western Bluebird favors semi-open woodlands and forest edges along the Pacific Coast and throughout the intermountain West. The Mountain Bluebird is adapted to high elevations, found in open grasslands and mountain meadows of the western cordillera.
The corvid species, the Blue Jay and Steller’s Jay, also exhibit distinct geographic ranges. The Blue Jay is a permanent resident or short-distance migrant throughout the eastern United States and southern Canada, thriving in forests and suburban parks. The Steller’s Jay replaces it in the West, inhabiting coniferous and mixed mountain forests. The Buntings are long-distance migrants. The Indigo Bunting breeds in eastern deciduous forest edges, while the Lazuli Bunting occupies brushy areas and riparian habitats in the West, with both species migrating to Central or South America for the winter.
Encouraging Blue Birds in Local Environments
For bluebirds, which are secondary cavity nesters, providing correctly sized nesting boxes with a 1.5-inch entrance hole is highly effective. These boxes should be placed in open areas with scattered trees, ideally spaced at least 100 yards apart to respect their territorial nature.
A reliable food source, especially protein-rich insects during the breeding season, attracts many blue species. Live or dried mealworms offered on a flat platform feeder are particularly effective for attracting bluebirds. Planting native shrubs that produce winter berries, such as sumac, dogwood, and serviceberry, offers a crucial food source when insects are scarce. Minimizing the use of chemical pesticides is important, as many blue birds rely heavily on foraging for ground insects to feed their young.