- 8.3–9.8 in
- 14.6 in
- 2.1–3 oz
- 7.9–8.7 in
- 14.6 in
- 1.8–2.4 oz
- About the size of a Red-winged Blackbird.
- Quiscale des Brewer (French)
- Brewer’s Blackbirds are social birds that nest in colonies of up to 100 birds. The first females to arrive choose a nest site to suit them, and later arrivals follow suit. Eggs are extremely variable in color and pattern. Some studies suggest the variability helps the eggs match the background pattern of the nest, helping to camouflage them.
- Most birds fly south for the winter, but a small number of Brewer’s Blackbirds fly west – leaving the frigid Canadian prairies for the milder coastal regions of British Columbia and Washington.
- Brewer’s Blackbirds cope well with humans and the development we bring. In the last century, they spread eastward from western Minnesota, taking advantage of agricultural fields, farmhouses, and towns. Where they overlap with the Common Grackle, the grackles take the streets and suburbs, leaving the Brewer’s Blackbirds to the fields and grasslands.
- Brewer’s Blackbirds are sometimes shot, trapped, or poisoned around agricultural fields in an attempt to protect crops. Although they do eat grains, this species’ appetite for insects makes it more of a farmer’s friend than a pest. Brewer’s Blackbirds are quick to notice new food sources and have been credited with helping to curb outbreaks of insect pests including weevils, cutworms, termites, grasshoppers, and tent caterpillars, among others.
- The oldest known Brewer’s Blackbird lived to be 12.5 years old.
Brewer’s Blackbirds live across the western half of North America, from below sea level in southern California to more than 8,000 feet in the Rocky Mountains. They occur in a huge variety of natural habitats – grasslands, marshes, meadows, woodland, coastal scrub, chaparral, and sagebrush – as well as many human-created habitats. These include lawns, golf courses, parks, city streets, agricultural fields, and power line rights-of-way.
Brewer’s Blackbirds eat mostly seeds and grains, but like many small birds they also eat lots of insects while they’re plentiful in summer – sometimes catching them in midair, or picking them off the backs of livestock. In towns, parks, and outdoor cafés, these birds will eat almost anything that’s not closely guarded. They’ve also been recorded eating small frogs, young voles, and a few kinds of nestling birds ranging from Brewer’s Sparrows to young Ring-necked Pheasants. Around marshes, you may even see them walk on lily pads to hunt aquatic insects.
- Clutch Size
- 3–7 eggs
- Number of Broods
- 1-2 broods
- Egg Length
- 0.9–1.1 in
- Egg Width
- 0.7–0.8 in
- Incubation Period
- 11–17 days
- Nestling Period
- 12–16 days
- Egg Description
- Pale gray to greenish white, clouded or spotted with brown, pink, yellow, violet, and gray.
- Condition at Hatching
- Naked except for sparse gray or black down; eyes closed; weighing about an eighth of an ounce.
Females build the nest cup from plant stems and a few twigs lined with fine dried grasses, rootlets, and hair. Sometimes they use mud or manure to cement the materials. The whole process takes 5-10 days, and the finished nest is about 6 inches across and 2 inches deep.
Brewer’s Blackbirds nest in colonies of a few to more than 100 pairs. After the first few females have chosen nest sites, others arrive and pick among nearby offerings. In some years this means you might find colonies in low shrubs; other years the same birds might nest in treetops. The birds typically nest in shrubs or trees near water, but may also nest in reeds and cattails or, occasionally, on the ground or in tree cavities.
Brewer’s Blackbirds feed on the ground and usually in the open, but perch much higher, often on telephone or power lines. They often flock with other species, including grackles, Red-winged Blackbirds, cowbirds, and starlings. Male Brewer’s Blackbirds watch over colonies by sitting at guard perches. They meet hawks, owls, gulls, and other predators with an alarm call, diving at and sometimes striking them to make them leave. Paired birds stop associating with each other after the nesting season ends, but typically reunite the next year if both birds return after winter.
Although they are common within their range, Brewer's Blackbirds populations declined by over 2 percent per year between 1966 and 2010 (amounting to a cumulative decline of 61 percent), according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 20 million, with 74 percent spending part of the year in the U.S., 26 percent breeding in Canada, and 25 percent wintering Mexico. The 2014 State of the Birds Report listed Brewer's Blackbirds as a Common Bird in Steep Decline, and this species rates a 9 out of 20 on the Partners in Flight Continental Concern Score. Various hazards facing the species include shooting, trapping, and poisoning (measures aimed at protecting agricultural crops), and collisions with windows and other structures. But in general, human activities such as agriculture and settlement have created places for Brewer’s Blackbirds to live.
Resident or medium-distance migrant. Birds of central North America fly up to 1,500 miles to the southern U.S. and southern Mexico for the winter. West of the Rockies, most birds are nonmigratory.
Brewer’s Blackbirds readily come to feeders, though they’re a bit clumsy when perching. You’re likely to get the best results by scattering seed on the ground or using an open platform feeder.
Find This Bird
Look for Brewer’s Blackbirds in two places: meandering along open ground, eyes peeled for crumbs, seeds, and insects; and perched up high, particularly on utility lines and in groups in the tops of trees.
Hear sounds and see videos of Brewer's Blackbird from the Cornell Lab of Ornithology's Macaulay Library archive
Check Project FeederWatch results for Brewer’s Blackbird sightings in your area. Then join the project and contribute your own sightings!
eBird needs your sightings – of Brewer’s Blackbirds, their rarer counterpart the Rusty Blackbird, and other birds. Help us understand the status and distribution of birds in North America.