Common Grackles are medium sized birds who are entirely black as adults and entirely dark brown as juveniles. Adults have an iridescent sheen across their body which vary from individual to individual. The sheen can be green, blue, rusty, purple, and rarely yellowish. Common Grackles have long, unique tapering tails that form a kite shape when flying. Their eye is brown as a Juvenile but turns yellow with a black pupil as they turn into an adult. Their bill is sharp, thick, and long, and like their legs, silvery gray.

Parent and Juvenile Common Grackles Foraging; Juvenile making begging calls.

Notice how the adult does a flicking motion, side to side, to flip away the leaves. Also, note how they do not jump as some other birds do when flipping the leaves.

European Starlings are very similar to grackles but they are slightly smaller and stockier, with longer throat feathers. In winter they gain speckled plumage, unlike winter grackles. In winter Starling also change their bill from yellow to dark brown. The juveniles of both speicies look very similar except for the tail, which is much shorter on the starling. Both species gather in large flocks and make weird noises.

Brown-Headed Cowbirds are similar to Grackles, but are much smaller. Females and juveniles have a stubbier bill, a whiter throat, and shorter tails compared to Grackles. Males have dark brown heads, stubby bills, and a shorter tail. They gather in flocks and prefer the same habitats as grackles.

Rusty Blackbirds are very similar to grackles, but note the slimmer bill, shorter tail, and slight rusty sheen. They also have a diagnostic call, which sounds like a creaky door swinging open. They will wade through still water up to their bellies, while Grackles rarely go into the water if not to bathe. Rusty Blackbirds also strongly prefer swampier habitats over fields, woods, and suburbia.

Red-winged Blackbirds are similar in many ways to grackles, but note the stripes on the female and the red and yellow on males. Their signature call is also a clue, which is a loud ooo-BLEK. Red winged blackbirds also prefer more moist habitats.

Both crow species that inhabit Arlington county are similar to grackles but are much larger, have rounder bills, have more obvious nasal feathers, and have shorter tails. Their voices also differ, crows will give caws, bill snaps, and rattles.