Brewer's Blackbird

Brewer's Blackbird (Euphagus cyanocephalus) is a medium-sized, highly social songbird native to western and central North America. Known for its comfortable coexistence with human development, this species is a familiar sight in suburban parks, agricultural fields, and bustling commercial parking lots. While they may initially appear to be plain black birds from a distance, a closer look in direct sunlight reveals the adult male's spectacular, multi-toned metallic iridescence and piercing pale eyes. They are highly gregarious birds, often foraging in active flocks alongside other blackbird species, starlings, and cowbirds.

Identifying Brewer's Blackbirds relies on observing eye color, plumage sheen, and structural profile:

• Adult Male: Entirely black plumage. In good light, it displays a distinct contrast: a glossy, purplish-blue sheen on the head and neck, shifting to a greenish-bronze reflection on the back, wings, and underparts. The eyes are a striking, bright pale yellow or white.
• Adult Female: Uniformly soft gray-brown overall, with slightly darker wings and tail. Unlike the males, females have dark brown eyes and often show a subtle, faint pale line over the eye.
• Juvenile: Similar to the adult female but with variable eye coloration developing in young males as they mature.

Similar Species

• Rusty Blackbird: Very similar in shape and size, but prefers wet, wooded habitats. The breeding male Rusty Blackbird has a slightly more slender, curved bill. In non-breeding plumage, Rusty Blackbirds display extensive warm, rusty-brown feather edges. Female Rusty Blackbirds have pale yellow eyes, unlike the dark-eyed female Brewer's.
• Brown-headed Cowbird: Features a much shorter, thicker, finch-like bill. The male cowbird has a chocolate-brown head and a dark, metallic body without the purplish-to-green contrast. Females are more uniform gray-brown with thick, short bills.
• Common Grackle: Significantly larger with a much longer, wedge- or keel-shaped tail, a heavier bill, and different vocalizations.

Brewer's Blackbirds thrive in open and semi-open country. Their natural habitats include grasslands, shrubby areas near streams, coastal marshes, and meadow borders. However, they are highly opportunistic and have heavily colonized human-altered landscapes. They are exceptionally common in city parks, golf courses, agricultural fields, lawns, and paved urban environments like shopping centers and outdoor eateries.

Geographic Range and Migration

Their breeding range extends from central Canada down through the western and central United States. While populations along the Pacific Coast and throughout the Southwest are year-round residents, northern and interior populations migrate south and east for the winter, spending the colder months in the southern United States and Mexico, often gathering in massive, mixed-species blackbird flocks.

Foraging and Diet

Brewer's Blackbirds are opportunistic omnivores. They forage primarily on the ground, walking with a characteristic rhythmic head-jerk as they search for food. Their natural diet consists largely of insects during the summer months, switching to seeds, grains, and berries in the fall and winter. In urban settings, they are bold scavengers, frequently feeding on discarded human food, bread crumbs, and trash around outdoor dining facilities.

Vocalizations

Their vocalizations are generally harsh and unmusical. The song of the male is a wheezy, creaking sound described as a buzzy ksh-e-e-r or sh-r-r-up, often accompanied by a physical display where the male puffs out his body feathers, spreads his tail, and slightly droops his wings. Their common call note is a sharp, flat, metallic chack or tick used to maintain contact with the flock.

Nesting and Socializing

These birds are colonial nesters, with up to several dozen pairs nesting in close proximity. Nests are sturdy cups built of twigs, grass, and weeds, cemented with mud or manure, and lined with fine grasses and animal hair. They are typically placed low in shrubs or trees, though they occasionally nest directly on the ground. During the breeding season, they are intensely protective of their territory, aggressively mobbing hawks, crows, ravens, and even humans who wander too close to their nesting sites.