Indigo Bunting ( Passerina cyanea )
Description: 5 1/2″ (14 cm) ADULT NONBREEDING MALE Has blotchy brown and blue plumage (caused by brown feather edges); resplendent again by spring. ADULT FEMALE Has brown plumage overall, darker above than below and with two faint wing bars and faint streaking on underparts. JUVENILE Recalls adult female; by first spring, male acquires some blue elements of adult’s plumage, but still looks blotchy.
Voice: Male Indigo Buntings whistle a bright, lively song of sharp, clear, high-pitched notes that lasts about 2 seconds. They are voluble, singing as many as 200 songs per hour at dawn and keeping up a pace of about one per minute for the rest of the day. Notes or phrases are often repeated in pairs: “what! what! where? where? see it! see it!” This pattern is recognizable, although the precise tune varies from place to place. Young Indigo Buntings learn their songs from males near where they settle to breed, and this leads to “song neighborhoods” in which all nearby males sing songs that are similar to each other and that are different from those sung more than a few hundred yards away.
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.
Nesting: 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 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.
Resource material provided by:
The Cornell Lab of Ornithology/ http://www.allaboutbirds.com