How do you identify a Brewer’s blackbird?

The Brewer’s blackbird (Euphagus cyanocephalus) is a medium-sized blackbird that is common across much of western North America. They are sexually dimorphic, meaning males and females have different plumage. Adult males are glossy black overall with a purplish iridescent sheen around the head and neck. Females are mostly dark brown but have lighter brown streaks on the underparts. Identifying a Brewer’s blackbird can be done by paying attention to the bird’s size, shape, color patterns and behavior. Knowing the geographic range where these birds occur is also helpful for identification. This article will provide tips on how to recognize a Brewer’s blackbird based on field marks and characteristics.

Size and Shape

Brewer’s blackbirds have a slender, long-tailed profile typical of icterids or blackbirds. They measure around 8 to 10 inches in length from bill to tail tip. Their wingspan ranges from about 13 to 17 inches. In terms of body proportions, these blackbirds have a medium-long tail that is rounded at the end. The legs and bill are also moderately long and pointed. Overall size and shape is very similar to a common grackle. Females may be slightly smaller than males. While seeing one by itself provides no scale, a Brewer’s blackbird is noticeably larger than a red-winged blackbird when seen together.

Plumage

The male Brewer’s blackbird in breeding plumage is unmistakable. Its entire body is covered in black lustrous feathers that have a metallic dark blue or purple iridescence when light hits them. This sheen is especially prominent on the head and neck. The eye is bright yellow. Legs and feet are also black. Non-breeding males have somewhat duller black plumage.

Females are considerably different with an overall brown color. The head and neck are darker brown while the underside is streaked with paler brown. The eye is yellowish. Immature Brewer’s blackbirds resemble adult females until they molt into adult male plumage by the following spring. In flight, the white underwing lining contrasts against the dark wing feathers.

Comparison to Common Grackle

The common grackle overlaps extensively in range with the Brewer’s blackbird and occupies similar habitats. Males are also glossy black but lack the strong purple iridescence on the head and neck. The eye is pale yellow rather than bright yellow. Females are brown but the plumage is darker overall compared to female Brewer’s. Juvenile common grackles can appear very similar however.

Behavior and Habits

Brewer’s blackbirds are social and congregate in large flocks, especially in the winter. They forage primarily on the ground in open areas. At bird feeders, they prefer platform or tray feeders rather than tube feeders. These blackbirds are omnivorous but eat mainly insects, grains and seeds. Their flight consists of stiff, shallow wingbeats interspersed with short glides. In flight, they form loose flocks.

Males are highly territorial during the breeding season. They sing and perform flight displays to defend their territory and attract females. Brewer’s blackbirds produce a variety of musical whistles, gurgles and chattering sounds. Calls include sharp “chek” notes. They nest either singly or in loose colonies, building an open cup nest in shrubs or small trees.

Range and Habitat

Brewer’s blackbirds occur from southern British Columbia east to Manitoba, and south throughout much of the western half of the United States. They are absent from higher elevations. During the breeding season they inhabit open deciduous or mixed woodlands, forest edges, parks, gardens and agricultural areas. Outside of breeding season they frequent more open country including fields, pastures, agricultural lands, feedlots, urban parks and gardens.

In winter, they may wander eastward and turn up well outside their normal range. But within their core western range, seeing a medium-sized black colored songbird with a long tail is very likely to be a Brewer’s blackbird.

Identifying Brewer’s Blackbirds – A Photo Guide

Here are some photos to help visually identify Brewer’s blackbirds:

Adult Male Brewer’s Blackbird

– Entirely black plumage with purple-blue gloss on head and neck
– Bright yellow eyes
– Long pointed bill

Adult Female Brewer’s Blackbird

– Brown plumage with darker head and neck
– Pale yellow eyes
– Streaked underside

Juvenile Brewer’s Blackbird

– Brown plumage similar to adult female
– Dark bill and gape

Brewer’s Blackbird vs Common Grackle

– Brewer’s blackbird has more slender shape, longer tail
– Male Brewer’s has purplish iridescence on head/neck, bright yellow eye
– Female Brewer’s is lighter brown overall with streaked underside
– Male grackle has paler yellow eye, female is darker brown

Typical Song and Calls

Here are some audio clips of the typical vocalizations of Brewer’s blackbirds:

Brewer’s Blackbird Song:

– Melodic and varied song sequences
– Whistles, gurgles, chatter sounds

Brewer’s Blackbird Calls:

– Harsh “check” notes
– Chatter calls

Nesting and Reproduction

– Build nests in small colonies or singly in low shrubs or trees
– Only female incubates eggs and cares for young
– Young fledge from nest at 13 to 14 days old

Conclusion

In summary, the combination of black color in males, brown streaked females, medium-large icterid shape, long tail, yellow eyes, and musical behavior help identify Brewer’s blackbirds. They are skilled vocalists and their flocks wheel and glide gracefully across open habitats. Paying attention to field marks, range, seasonal plumage differences, and habits allows even beginning birders to recognize these striking birds. Brewer’s blackbirds add a beautiful dash of color and energy to any outdoor environment across western North America.