Common Grackle or Brewer’s Blackbird?
Here's how to tell the difference
Common Grackle
Brewer’s Blackbird
Common Grackle
Quiscalus quiscula
Also known as: Blackbird
General appearance
The common grackle is about the size of a crow, bearing a distinctive long tail with a crease down the middle. Coloring varies with two forms presented, namely, the 'Bronzed Grackle' and the 'Purple Grackle.' The former spots a bronzy body offset by a blue-black head while the latter shines with glosses of purple and green, offering less contrast.
Male vs female
Physical variations between the sexes are not explicitly stated. However, based on the Bronzed and Purple forms noted, it could be inferred that some slight difference in color intensity and gloss may exist.
Juvenile
Juvenile grackles present dark eyes in contrast to the whitish-yellow eye color observed in adults. Molting, a period prevalent in late summer, results in these younger birds having short or fragmented tails.
Size
11.0 - 13.4 in/2.6 - 5.0 oz
There's more to learn about Common Grackle
View full detailsBrewer’s Blackbird
Euphagus cyanocephalus
General appearance
The Brewer’s blackbird is a medium-sized songbird with a slender body and a rounded head. It has a pointed bill and relatively long legs. The overall plumage is glossy with an iridescent sheen under certain lighting conditions, predominantly appearing black from a distance.
Male vs female
Male Brewer’s blackbirds are characterized by their glossy black overall color, with a purplish sheen on the head and greenish gloss on the body and wings. Females, however, display a more subdued appearance, with brownish-gray plumage, pale throat, and lack the iridescence that males exhibit. Their eyes are darker than those of males.
Juvenile
Juvenile Brewer’s blackbirds resemble females but are generally duller in tone. They have brownish feathers with a streaky appearance and lack the iridescence seen in adults. Unlike adults, their eyes are typically dark brown rather than the yellow seen in mature males.
Size
7.9 - 9.8 in/2.0 - 2.4 oz
There's more to learn about Brewer’s Blackbird
View full detailsHow to tell the Common Grackle from the Brewer’s Blackbird
Visual differences
The Common Grackle is larger than the Brewer's Blackbird, measuring 11-13 inches with a weight of 2.6-5 oz, compared to the Brewer's 8-10 inches and 2-2.4 oz. Grackles have a longer tail and a more pronounced, keel-shaped bill, whereas Brewer's have a slender body and pointed bill. The Grackle's plumage features bronzed or purplish-green gloss, while the Brewer's male shows a purplish head and greenish body. The female Brewer's is brownish-gray, lacking iridescence, contrasting with the less pronounced sexual dimorphism in Grackles.
Key differences and behavior
Common Grackles (11-13.4 in, 2.6-5 oz) tend to forage on the ground and can be aggressive at feeders, stealing food from other birds. They are omnivorous, eating insects, seeds, and small animals, often using unique methods like "anting" for pest control. Grackles prefer semi-open spaces, nesting in small colonies often near water. Their courtship involves males showcasing plumage and singing. Brewer’s Blackbirds (7.9-9.8 in, 2-2.4 oz) primarily eat insects, benefiting agriculture, yet they're mistakenly seen as pests. Highly social, they nest in larger colonies, and males attract mates through song and flight displays. While both species thrive in human-altered environments, Brewer's Blackbirds are more adaptive to urban settings. Unlike the grackle’s aggressive feeder behavior, Brewer’s Blackbirds prefer natural foraging but will visit feeders for grains and seeds.
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