Great-tailed grackles are large blackbirds with long legs, a fairly flat crown, long tail, long, down-curved bill, and pale eyes. Adult male upperparts are black, with a purple sheen on the head and back. Eyes are bright yellow, and in breeding plumage, the tail is very long, with the edges turned up. The underparts are black with a purple sheen. The female is smaller, shorter-tailed, and dark brown, with a lighter upper breast, throat, and eyebrow. The eye is pale yellow. Juveniles resemble females but have dark eyes. The song is a series of clear, rising whistles, wiks, clacks, hisses, chucks, and a series of clicks.
Similar species: In Missouri, the common grackle is more common and has a wider distribution. It is smaller, with a shorter tail and a rounder (not flattened) crown, and it is mostly bronze-iridescent, with a bluish-purple head. A close relative, the boat-tailed grackle, is very similar to the great-tailed grackle but does not occur in Missouri. It has a coastal distribution ranging from eastern Texas, along the Gulf of Mexico, including most of Florida, and up the Atlantic coast as far as New York. It doesn’t stray far from saltwater marshes along coasts. Its range overlaps the great-tailed grackle’s along the coast in parts of Louisiana and Texas.
Length: 18 inches (male), 15 inches (female). (As with all bird measurements, length is from tip of bill to tip of tail.)
Habitat and Conservation
Usually seen in open areas with scattered trees, including marshes, cattle feedlots, agricultural fields, and pastures. Over the last 150 years, the great-tailed grackle has been expanding its range northward through Mexico and the United States. It reached Missouri in 1976, and the first nest was found in 1979; both records were in Holt County. Since then, it has been observed throughout the western third of Missouri each year and nests in many locations.
These grackles eat insects and seeds, often while walking on the ground. They frequent agricultural areas to eat spilled or newly planted grain. They eat a variety of insects and other small animals, especially during breeding season, when growing young require a high-protein diet. They sometimes wade into shallow water to snatch tadpoles, small frogs, and other aquatic prey.
Rare to uncommon permanent resident in western Missouri; accidental elsewhere. In 1900, great-tailed grackles were unknown in the United States, except for the southern tip of Texas. But the expansion of irrigated croplands and parklike urban areas in the US southwest and Great Plains created favorable habitat for them, allowing them to expand northward. If you look in mid-20th-century bird books, you will not find this species illustrated. At that time, it was considered a southern race of the boat-tailed grackle. As the southern, “great-tailed form” expanded and met the Gulf of Mexico boat-tailed grackles, intergrades between the two subspecies were apparently reported. However, the two populations currently breed in the same area with no hybrids occurring between the two species.
Adult male great-tailed grackles use several displays to court females and intimidate other males, including ruff-out, sky-pointing, and flight displays. In Missouri, females usually build their large, bulky cup nests over water in cattails or in shrubs. The nests are constructed of a variety of fibrous plant stems plus string, plastic bags, and other miscellaneous materials, with the upper rim woven onto upright supporting branches. Mud or cow manure plasters the inner walls, which are lined with a cushion of soft, fine grasses. Clutches comprise 1–5 eggs, which are incubated for about 2 weeks. After hatching, the young remain in the nest another 20–23 days. A great-tailed grackle can live to be at least 7 years old.
In the Southwest, great-tailed grackles have become crop pests on sprouting grain and in citrus groves. Great-tailed grackles proliferate in places humans live — cities, farms, and parks, for instance — much like the introduced rock pigeons and house sparrows. But these grackles are native to North America, and their populations are simply expanding due to our alteration of habitats. It is interesting to note that the range of its relative the common grackle has expanded westward, as farms have been carved out of forests, while their numbers are decreasing in the east as cities and suburbs shrink the farmland.
Great-tailed grackles are social birds, roosting in flocks, communicating via a huge variety of whistles and chattering sounds, and establishing and defending breeding territories. Their problem-solving ability is admirable, and they have demonstrated flexibility in behavior, changing their tactics as circumstances change.
About 350 species of birds are likely to be seen in Missouri, though nearly 400 have been recorded within our borders. Most people know a bird when they see one — it has feathers, wings, and a bill. Birds are warm-blooded, and most species can fly. Many migrate hundreds or thousands of miles. Birds lay hard-shelled eggs (often in a nest), and the parents care for the young. Many communicate with songs and calls.