Grackles are blackbirds found across North America, recognized by their striking appearance and distinctive vocalizations. They are a common sight in diverse environments, from open fields to urban settings. Their glossy, dark plumage and characteristic sounds make them easily identifiable. Grackles are known for their adaptability.
Identifying Grackles
Grackles are medium-sized blackbirds, larger and longer-tailed than many other species. The Common Grackle measures 11 to 13 inches long with a 14 to 18-inch wingspan. Their plumage appears black from a distance but reveals iridescent sheens of purple, blue, and green in good light. This metallic luster is pronounced on the head and body, with some subspecies exhibiting bronze or brassy tones.
Grackles have piercing, bright golden-yellow eyes. They possess a long, tapered bill with a slight downward curve, and their legs are also long. Male grackles, especially the Common Grackle, display a long, V-shaped or “keeled” tail noticeable in flight. Females are generally smaller, less iridescent, and have shorter tails that do not always show the same keel shape.
Grackle vocalizations are harsh, creaky, or grating. The Common Grackle’s song sounds like a rusty gate or a “kh-sheee” or “kh-reezzh.” Great-tailed Grackles are known for loud, unpleasant noises and mechanical rattles. These sounds contribute to their noticeable presence.
Where Grackles Live
Grackles inhabit a wide geographical range across North America, primarily east of the Rocky Mountains. The Common Grackle breeds throughout much of the United States and southern Canada. They are partial migrants in the southeastern part of their range, moving shorter distances between breeding and wintering sites. Northern populations typically migrate south for winter.
Grackles are highly adaptable and thrive in various environments. They are commonly found in open woodlands, forest edges, grasslands, meadows, and swamps. Grackles also frequently inhabit human-modified landscapes such as agricultural fields, suburban parks, urban areas, and feedlots. Their ability to utilize scattered trees for nesting and open ground for foraging allows them to flourish.
Grackles often favor areas near water sources, including marshes, stream sides, and pond edges. While they can be found in a broad array of habitats, dense, old-growth forests are among the few places where Common Grackles are less prevalent.
Grackle Behavior and Diet
Grackles are highly social birds, frequently forming large flocks, particularly outside of the breeding season. These communal roosts can number in the millions and may include other blackbird species like Red-winged Blackbirds and European Starlings. Common Grackles often nest in colonies.
Grackles are ground foragers, often seen walking on lawns and fields as they search for food. They probe the ground with their bills and may also wade into shallow water to find prey. Their diet is omnivorous and diverse. Insects, such as beetle grubs, grasshoppers, and caterpillars, form a significant part of their diet, especially during the summer.
Beyond insects, grackles consume seeds, grains (like corn and rice), berries, and fruits. They are also opportunistic predators, eating small vertebrates such as minnows, frogs, lizards, and the eggs and young of other birds. Grackles exhibit intelligence in their foraging, sometimes following plows to catch disturbed invertebrates or stealing worms from American Robins. They possess a specialized keel inside their upper mandible, which aids in cracking hard nuts and kernels.
Grackles and Humans
Grackles frequently interact with human environments and are often seen in suburban and urban areas. Their large flocks can lead to perceptions of them as “nuisance” birds, particularly due to noise and their consumption of agricultural crops like corn. They also frequent bird feeders, often dominating them and consuming large quantities of seed.
Despite some negative perceptions, grackles play an ecological role, particularly in controlling insect populations. Their diverse diet includes many insects that can be pests to crops and gardens. Grackles are highly adaptable to human-modified landscapes, utilizing parks, fields, and urban structures for nesting and foraging. Their intelligence is noteworthy, as they can solve problems related to food acquisition. Grackles are protected in the U.S. by the Migratory Bird Treaty Act of 1918.