- 4.7–5.1 in
- 7.5–8.7 in
- 0.4–0.6 oz
- Sparrow-sized; slightly smaller than a House Finch
- Passerin indigo (French)
- Azulito, Gorrión, Ruicito (Spanish)
- Indigo Buntings migrate at night, using the stars for guidance. Researchers demonstrated this process in the late 1960s by studying captive Indigo Buntings in a planetarium and then under the natural night sky. The birds possess an internal clock that enables them to continually adjust their angle of orientation to a star—even as that star moves through the night sky.
- Indigo Buntings learn their songs as youngsters, from nearby males but not from their fathers. Buntings a few hundred yards apart generally sing different songs, while those in the same "song neighborhood" share nearly identical songs. A local song may persist up to 20 years, gradually changing as new singers add novel variations.
- Like all other blue birds, Indigo Buntings lack blue pigment. Their jewel-like color comes instead from microscopic structures in the feathers that refract and reflect blue light, much like the airborne particles that cause the sky to look blue.
- Bunting plumage does contain the pigment melanin, whose dull brown-black hue you can see if you hold a blue feather up so the light comes from behind it, instead of toward it.
- Indigo and Lazuli buntings defend territories against each other in the western Great Plains where they occur together, share songs, and sometimes interbreed.
- The oldest known wild Indigo Bunting was 8 years, 3 months old.
Indigo Buntings breed in brushy and weedy areas. They're common on the edges of woods and fields; along roads, streams, rivers, and powerline cuts; in logged forest plots, brushy canyons, and abandoned fields where shrubby growth is returning. While migrating and in winter, Indigo Buntings forage in fields, lawns, grasslands, rice fields, as well as in shrubs, and trees.
Indigo Buntings eat small seeds, berries, buds, and insects. Common seed forage includes thistles, dandelions, goldenrods, and grain such as oats; berries eaten include blueberries, strawberries, blackberries, serviceberries, and elderberries. Spiders and insect prey, which form the majority of their diet during summer months, may include caterpillars, grasshoppers, aphids, cicadas and beetles such as canker worms, click beetles, and weevils. The brown-tail moth caterpillar, which is covered with noxious hairs that cause nasty rashes and respiratory problems in people, presents no obstacle to a hungry bunting. On arrival to breeding grounds in spring, Indigo Buntings may feed on twigs, buds, and leaves of trees including aspen, cottonwood, oaks, beech, elm, maple, and hickory.
- Clutch Size
- 3–4 eggs
- Number of Broods
- 1-3 broods
- Egg Length
- 0.7–0.8 in
- Egg Width
- 0.5–0.6 in
- Incubation Period
- 11–14 days
- Nestling Period
- 8–14 days
- Egg Description
- Unmarked white; a few have brownish spots.
- Condition at Hatching
- Naked except for sparse down; eyes closed; helpless.
The female Indigo Bunting builds the nest alone—a process that takes up to 8 days early in the season and as little as 2 days later in the summer. The male may watch but does not participate. The nest is an open cup woven of leaves, grasses, stems, and bark, and wrapped with spider web. The inside of the cup is lined with slender grasses, tiny roots, strips of thin bark, thistle down, and sometimes deer hair. The cup is about 1.5 inches deep inside, with an outside diameter of 3 inches and an inside diameter of two inches.
Indigo Buntings nest in fields and on the edges of woods, roadsides, and railroad rights-of-way. The female chooses a concealed nest site in low vegetation, within a meter of the ground. She locates the nest in a crotch or fork where branches meet, amid a supporting network of vertical and diagonal twigs. Occasionally an Indigo Bunting builds her nest in crop plants like corn or soybeans.
Foraging for seeds and gleaning insects off branches in low vegetation, Indigo Buntings hop along the ground and cling athletically to stems and reeds. Singing males tend to perch high in shrubs, trees, or on telephone lines. When disturbed, an Indigo Bunting may fly to the top of a shrub, raise its crest feathers, and swing its tail from side to side. Indigo Buntings usually forage alone during the breeding season; on their wintering grounds and during spring and fall migration, they feed in flocks on lawns and open grasslands. Males defending territory approach each other with slow, fluttering "butterfly" display flight, holding their wings at right angles to their bodies. Early in the breeding season, you may see two males grappling in the air and falling to the ground, singing loudly, clasping each other's feet.
Indigo Buntings are generally abundant throughout their range. Populations of these birds decrease with intensive agriculture, reforestation, frequent mowing of roadsides and fields, and increasing urbanization; they increase with the expansion of shrubby, weedy habitat. Their showy plumage can be a handicap, as Indigo Buntings are prized as cage birds in parts of Mexico, where they have been trapped for illegal sale. Indigo Buntings and many other small birds are commonly hunted on their tropical wintering grounds. During migration, many die after flying into buildings and transmission towers. These birds breed and sing along roadsides, and collisions with vehicles kill many birds in summer. In the 1970s, Indigo Buntings colonized Canada's Maritime Provinces, moving northward from their established breeding range in Maine. A warming climate may drive populations farther northward.
- Payne, R. B. 1992. Indigo Bunting (Passerina cyanea). In The Birds of North America, No. 4 (A. Poole, Peter Stettenheim, and F. Gill, Eds.). The Birds of North America Online, Ithaca, New York.
- Dunne, P. 2006. Pete Dunne's Essential Field Guide Companion. Houghton Mifflin, New York.
- Emlen, S. T. 1967. Migratory orientation in the Indigo Bunting, Passerina cyanea. Part II: Evidence for use of celestial cues. Auk 84:309-342.
- Sibley, D. A. 2003. The Sibley Field Guide to Birds of Western North America. Knopf, New York.
- Simon, H. 1971. The Splendor of Iridescence: Structural Colors in the Animal World. Dodd, Mead, New York.
- USGS Patuxent Wildlife Research Center. 2011. Longevity Records of North American Birds.
- Wiltschko, W., R. Wiltschko, S. T. Emlen, and N. J. Demong. 1980. Nocturnal activity and orientation behavior during spring migration and early summer in the Indigo Bunting, Passerina cyanea. J. Comp. Physiol. 137:47-49.
Long-distance migrant. Indigo Buntings fly about 1,200 miles each way between breeding grounds in eastern North America and wintering areas from southern Florida to northern South America. The birds tend to migrate more or less due south, so buntings that breed in the eastern part of their breeding range also winter in the eastern part of the winter range, while western breeders are western winterers.
You can attract Indigo Buntings to your yard with feeders, particularly with small seeds such as thistle or nyjer. Indigo Buntings also eat many insects, so live mealworms may attract them as well. There’s more about feeding birds at our Attract Birds pages.
Find This Bird
Look for Indigo Buntings in midsummer along rural roads, where they often sing from telephone lines or wooded edges for hours on end. One of the best ways to find them is to learn to recognize the bouncy quality of the paired notes in their song. During migration you may see large flocks of Indigo Buntings feeding in agricultural fields or on lawns. In fall their mostly brown plumage can make them tricky to identify, but look for tinges of blue in the wings or tail as a giveaway.