European Starling vs Common Grackle: How To Tell Them Apart

A noisy flock of dark, iridescent birds descends on your garden, stripping the feeders bare in minutes. Are they starlings or grackles? Though they share a penchant for travelling in boisterous groups and shimmering in the sunlight, the European Starling (Sturnus vulgaris) and the Common Grackle (Quiscalus quiscula) are entirely different species. Once you know what to look for—from eye colour to tail length—telling them apart takes only a glance.

The quickest way to separate these two birds is by looking at their overall proportions. The Common Grackle is a noticeably larger, lankier bird. Measuring between 28 and 34 cm in length, it is roughly the size of a Mourning Dove. Its most defining structural feature is its long, keel-shaped tail, which often folds into a distinct V-shape during flight.

In contrast, the European Starling is a compact, stocky bird, measuring just 19 to 23 cm long. It has a short, square-tipped tail that makes its wings look disproportionately pointed in flight. If the bird looks stretched out with a trailing tail, it is a grackle. If it looks like a flying cigar with short tail feathers, it is a starling.

Sunlight reveals the true colours of both species, but their feather patterns behave entirely differently throughout the year. Common Grackles maintain a relatively consistent appearance year-round. Their bodies are a glossy bronze or purple, depending on the subspecies, with a contrasting iridescent blue or purple head. Crucially, their plumage is always solid and unspotted.

European Starlings undergo a dramatic seasonal transformation. In autumn, after moulting, they emerge covered in striking white spots—often called their "winter plumage." As winter turns to spring, the white tips of these feathers gradually wear away, revealing the glossy, unspotted, iridescent green and purple breeding plumage beneath.

A close look at the head will immediately confirm your identification. Adult Common Grackles have piercing, bright yellow eyes that give them an intense, almost glaring expression. Their bills are thick, dark, and feature a slight downward curve at the tip, perfectly adapted for cracking acorns and hard seeds.

European Starlings have dark brown eyes that blend into their dark facial feathers. Their bills are slender, straight, and sharply pointed. The starling's bill also changes colour with the seasons: it is dark brown or black during the winter months and turns a vibrant, unmistakable yellow during the spring breeding season.

Both species are highly gregarious and can quickly overwhelm a garden feeding station, but their feeding styles differ. Grackles are heavy-footed birds that prefer to walk deliberately across the ground or dominate platform feeders. They have a particular fondness for cracked corn, sunflower seeds, and peanuts.

Starlings are more agile and aggressive at hanging feeders. They are notorious for swarming suet blocks and devouring mealworms in a matter of minutes. While grackles use their strong bills to crush hard food, starlings use a technique called "open-bill probing"—driving their closed bill into the soil or a suet block and then springing it open to create a hole and extract the food.

Beyond the bird feeder, these two species have distinct ecological roles. The Common Grackle is an opportunistic omnivore with a diet that leans heavily towards plant matter, especially during the winter. They frequently descend on cornfields to pull up sprouting seedlings or feast on ripening ears. However, they also hunt for insects, catch small fish in shallow water, and occasionally raid the nests of other birds for eggs or nestlings.

European Starlings are primarily insectivores during the breeding season. Their unique open-bill probing technique allows them to hunt for leatherjackets (cranefly larvae) and earthworms hidden beneath the soil surface. This makes them a common sight on short-grass lawns, golf courses, and agricultural pastures. In the autumn and winter, their diet shifts to include more fruits, berries, and seeds, which helps them survive when insect populations plummet.

Common Grackles often nest in loose colonies, preferring the dense cover of coniferous trees. The female builds a bulky cup nest out of twigs, leaves, and grasses, often reinforcing the structure with mud. She typically lays four to five eggs, which are a pale greenish-blue with dark brown scrawls. The male will fiercely defend the nesting territory, sometimes dive-bombing humans or predators that venture too close.

European Starlings are cavity nesters. They rely on natural tree hollows, old woodpecker holes, or man-made structures like building crevices and nest boxes. This reliance on cavities often brings them into direct competition with native birds like bluebirds and woodpeckers. The female lays four to six pale blue, unmarked eggs. Both parents share the incubation duties and work tirelessly to feed the chicks a diet consisting almost entirely of insects.

The Common Grackle is a true North American native, found year-round across the eastern and midwestern United States, and breeding as far north as central Canada. They thrive in agricultural fields, city parks, and suburban gardens.

The European Starling, as its name suggests, is not native to the Americas. It is naturally found across Europe, Asia, and North Africa. However, in 1890, a Shakespeare enthusiast released around 100 starlings into New York's Central Park. From that small flock, the population exploded. Today, an estimated 200 million starlings span the entire North American continent.

While both birds are common sights, their population trajectories are moving in opposite directions. The Common Grackle, despite its abundance, has seen a significant population decline of over 50% since the 1960s. This drop is largely attributed to habitat loss, pesticide use, and aggressive pest-control measures aimed at protecting agricultural crops.

The European Starling presents a different conservation story. In North America, their population remains massive, though it has slightly declined from its peak in the mid-20th century. However, in their native European range, starling populations have plummeted. In the UK, for example, the European Starling is red-listed as a species of high conservation concern due to a severe decline in breeding numbers, driven by the loss of permanent pasture and the intensification of agriculture.

Yes. During the autumn and winter months, after the breeding season has finished, it is very common to see mixed flocks. Starlings and grackles will often join forces with Red-winged Blackbirds and Brown-headed Cowbirds to form massive foraging flocks that can number in the tens of thousands.

Despite their superficial similarities, they belong to entirely different scientific families. The Common Grackle is a member of the Icteridae family (New World blackbirds), which includes orioles and meadowlarks. The European Starling belongs to the Sturnidae family, a diverse group of Old World birds.

If you close your eyes, you can easily tell them apart. A Common Grackle's signature call is a harsh, squeaky sound that is frequently compared to the swinging of a rusty metal gate. European Starlings, on the other hand, produce a continuous stream of chatters, clicks, and whistles. They are also masterful mimics, capable of perfectly replicating the calls of other birds, car alarms, and even human speech.

It is a common misconception that female grackles outnumber males due to differing life expectancies. In reality, the sex ratio of Common Grackles is roughly equal. The confusion often stems from the fact that females are slightly smaller and have less iridescent plumage, making them look somewhat different from the highly glossy males. During the breeding season, males are also more conspicuous as they perform elaborate displays, puffing up their feathers and spreading their tails to attract mates.

Both species exhibit varied migratory behaviours depending on their location. Common Grackles in the northern parts of their range (such as Canada and the northern US) will migrate south in massive flocks to escape the harsh winter, while those in the southern US remain year-round residents. European Starlings follow a similar pattern; northern populations in Europe and North America will migrate southwards, whereas birds in milder climates are largely sedentary.