Indigo Bunting

The indigo bunting, Passerina cyanea, is a small, seed-eating avian member of the cardinal family. This diminutive bird is known for its vibrant blue plumage in males during the breeding season and its migratory habits. Females and non-breeding males are predominantly brown, with the males exhibiting a hint of their summer blue.

Identification Tips

Adult males in breeding plumage are a brilliant blue, with darker wings and tail. Females and juveniles are brown with faint streaking. The species exhibits sexual dimorphism, with males changing coloration seasonally. Look for a short, conical beak and a body length of 11.5–13 cm.

Habitat

Indigo buntings favor brushy forest edges, open deciduous woods, and farmland. They thrive in areas with a mix of clearings and dense shrubbery, which provide both feeding grounds and nesting sites.

Distribution

During the breeding season, these birds can be found from southern Canada to northern Florida and from eastern Texas to southern Nevada. Come winter, they migrate to regions from southern Florida to northern South America.

Behaviour

The indigo bunting is a solitary feeder during the breeding season but may join flocks in winter. Males are territorial and will sing from perches to defend their domain and attract mates. They are monogamous, though not strictly faithful, and may hybridize with the lazuli bunting where their ranges overlap.

Song & Calls

Males sing a high-pitched, buzzed "sweet-sweet chew-chew sweet-sweet" to mark territory and attract females. Both sexes use a sharp "chip!" as an alarm call and a buzzed "zeeep" in flight.

Breeding

Females build nests in dense shrubs or low trees, laying 1-4 eggs, which they incubate alone. The species raises one to two broods per year, with males feeding fledglings while females prepare for the next clutch.

Similar Species

The lazuli bunting is similar but has orange on the breast and white wing bars. Where their ranges meet, the two species may interbreed.

Diet and Feeding

Indigo buntings forage for insects, seeds, and berries. Insects are a staple during the breeding season, while seeds predominate in the winter diet. Young are fed protein-rich insects to support their growth.

Conservation status

The indigo bunting is classified as Least Concern, with a stable population estimated at 28 million individuals. Its extensive range and adaptability to human-altered landscapes have helped maintain its numbers.

References

• BirdLife International (2018). "Passerina cyanea". IUCN Red List of Threatened Species. 2018.
• Sibley, Charles Gald; Burt Leavelle Monroe (1991). Distribution and Taxonomy of Birds of the World. Yale University Press.
• Kaufman, Kenneth (2001). Lives of North American Birds. HMCo Field Guides.