Blue Grosbeak

Passerina caerulea

Order PASSERIFORMES - Family CARDINALIDAE

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1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

A beautiful blue bird with silvery bill and chestnut wingbars, the Blue Grosbeak is an uncommon bird of shrubby habitats across the southern United States.

Cool Facts

• The Blue Grosbeak formerly was placed in its own genus, Guiraca. Similarities with buntings in genetics, behavior, molts, and plumages led to its inclusion in the bunting genus Passerina. Genetic evidence indicates that the Lazuli Bunting is its closest relative.
• In the southern part of its breeding range, the Blue Grosbeak commonly raises two broods per year.

Description

• Size: 15-16 cm (6-6 in)
• Wingspan: 28 cm (11 in)
• Weight: 26-31 g (0.92-1.09 ounces)

• Medium-sized songbird.
• Large silver-gray bill.
• Male deep blue with two brown wingbars.
• Female mostly brown with two brown wingbars.

Blackish wings and tail. Eyes dark brown. Legs blackish.

Sex Differences

Male is mostly deep blue; female is brown.

Male

Black in front of eyes extending down to bill. Flight feathers dark brown to black, with blue edging.
Breeding (Alternate) Plumage: Blue all over.
Nonbreeding (Basic) Plumage: Body blue with brownish feather edges.

Female

Brown all over, with some blue feathers on back. Flight feathers dark brown to black, with brown edging.

Immature

First-year female resembles adult female, with even less blue on the upperparts. First-year male, through the first full summer of life, shows plumage intermediate between that of adult female and adult male, with variable amounts of blue mixed with brown.

Similar Species

• Eastern Bluebird has reddish chest and white belly.
• Indigo Bunting is similar in all plumages, but is much smaller, has a smaller bill, with wingbars less distinct or lacking.
• Immature Lazuli Bunting is similar, but is smaller, paler, and has a smaller bill.
• Female and juvenile Brown-headed Cowbird lack wingbars and may be streaked on breast.

Sound

Song is a long continuous musical warble, similar to that of Indigo Bunting but without paired phrases. Call is a low buzzy "bzzt" or a loud metallic "tink."

»listen to songs of this species

Range

Summer Range

Breeds from central California across the central United States, as far northward as southern North Dakota, to northern New Jersey. Generally does not breed along Gulf Coast. Also breeds throughout Mexico and Central America.

Winter Range

Winters mostly from Mexico to Panama. Also recorded in winter in South America.

Habitat

Forest edge, fields, power-line cuts, riparian areas, hedgerows, and other areas with medium-sized trees and low shrub density.

Food

Insects, other invertebrates, and seeds. Gathers in rice fields during migration.

Behavior

Foraging

Large bill can handle large seeds, including corn, and insects such as mantids and grasshoppers.

Reproduction

Nest Type

Compact cup made of twigs, bark, rootlets, and other fibers and strips of material, placed low in shrubs or small trees.

Egg Description

Pale blue and unmarked.

Clutch Size

Usually 4 eggs. Range: 3-5.

Condition at Hatching

Helpless.

Conservation Status

Populations stable or increasing. Range has expanded northward since early 20th century. Brown-headed Cowbird commonly lays its own eggs in Blue Grosbeak nests; specific effects on populations not documented.

Other Names

Guiraca bleue (French)
Piquirgrueso azul, Ruiz azul grande (Spanish)

Sources used to construct this page:

1. Banks, R. C., et al. 2002. Forty-third supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 119: 897-906.
2. Ingold, J. L. 1993. Blue Grosbeak (Guiraca caerulea ). In The Birds of North America, No. 79 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists' Union.