Common Grackle vs Boat-tailed Grackle

In short

The Common Grackle and Boat-tailed Grackle are both large, iridescent blackbirds, but the Boat-tailed Grackle is typically found along coastal areas and has a notably longer tail. Female Boat-tailed Grackles are cinnamon-colored, unlike the more uniformly dark female Common Grackles.

Identification tips

1. Look for the longer tail of the Boat-tailed Grackle. 2. Note the habitat: coastal for Boat-tailed, more varied for Common. 3. Check the plumage: cinnamon females indicate Boat-tailed. 4. Observe behavior: large colonies suggest Boat-tailed during breeding season.

Size

Boat-tailed Grackles are generally larger with a longer tail compared to Common Grackles.

Plumage

Male Common Grackles have a glossy black plumage with a purple or bronze sheen, while male Boat-tailed Grackles display a blue-green iridescence. Female Boat-tailed Grackles are cinnamon-colored, contrasting with the more subdued brownish tones of female Common Grackles.

Behaviour

Boat-tailed Grackles exhibit a unique harem polygyny mating system and are often seen in large colonies during breeding. Common Grackles are more flexible in their behavior and can be found in a variety of habitats.

Habitat

Common Grackles are widespread across North America, often found in open areas and near human settlements. Boat-tailed Grackles are more restricted to coastal regions and marshes.

Voice

Both species have complex vocalizations, but specific details on differences are limited. Boat-tailed Grackles' vocalizations may play a role in maintaining reproductive isolation from similar species.